C 64   Kernal ROM
; continuation of EXP function

E000   85 56      STA $56
E002   20 0F BC   JSR $BC0F
E005   A5 61      LDA $61
E007   C9 88      CMP #$88
E009   90 03      BCC $E00E
E00B   20 D4 BA   JSR $BAD4
E00E   20 CC BC   JSR $BCCC
E011   A5 07      LDA $07
E013   18         CLC
E014   69 81      ADC #$81
E016   F0 F3      BEQ $E00B
E018   38         SEC
E019   E9 01      SBC #$01
E01B   48         PHA
E01C   A2 05      LDX #$05
E01E   B5 69      LDA $69,X
E020   B4 61      LDY $61,X
E022   95 61      STA $61,X
E024   94 69      STY $69,X
E026   CA         DEX
E027   10 F5      BPL $E01E
E029   A5 56      LDA $56
E02B   85 70      STA $70
E02D   20 53 B8   JSR $B853
E030   20 B4 BF   JSR $BFB4
E033   A9 C4      LDA #$C4
E035   A0 BF      LDY #$BF
E037   20 59 E0   JSR $E059
E03A   A9 00      LDA #$00
E03C   85 6F      STA $6F
E03E   68         PLA
E03F   20 B9 BA   JSR $BAB9
E042   60         RTS

; compute odd degrees for SIN and ATN

E043   85 71      STA $71
E045   84 72      STY $72
E047   20 CA BB   JSR $BBCA
E04A   A9 57      LDA #$57
E04C   20 28 BA   JSR $BA28
E04F   20 5D E0   JSR $E05D
E052   A9 57      LDA #$57
E054   A0 00      LDY #$00
E056   4C 28 BA   JMP $BA28

; compute polynomials according to table indexed by AY

E059   85 71      STA $71
E05B   84 72      STY $72
E05D   20 C7 BB   JSR $BBC7
E060   B1 71      LDA ($71),Y
E062   85 67      STA $67
E064   A4 71      LDY $71
E066   C8         INY
E067   98         TYA
E068   D0 02      BNE $E06C
E06A   E6 72      INC $72
E06C   85 71      STA $71
E06E   A4 72      LDY $72
E070   20 28 BA   JSR $BA28
E073   A5 71      LDA $71
E075   A4 72      LDY $72
E077   18         CLC
E078   69 05      ADC #$05
E07A   90 01      BCC $E07D
E07C   C8         INY
E07D   85 71      STA $71
E07F   84 72      STY $72
E081   20 67 B8   JSR $B867
E084   A9 5C      LDA #$5C
E086   A0 00      LDY #$00
E088   C6 67      DEC $67
E08A   D0 E4      BNE $E070
E08C   60         RTS

; float numbers for RND

E08D   .BY $98,$35,$44,$7A,$00
E092   .BY $68,$28,$B1,$46,$00

; RND function

E097   20 2B BC   JSR $BC2B
E09A   30 37      BMI $E0D3
E09C   D0 20      BNE $E0BE
E09E   20 F3 FF   JSR $FFF3
E0A1   86 22      STX $22
E0A3   84 23      STY $23
E0A5   A0 04      LDY #$04
E0A7   B1 22      LDA ($22),Y
E0A9   85 62      STA $62
E0AB   C8         INY
E0AC   B1 22      LDA ($22),Y
E0AE   85 64      STA $64
E0B0   A0 08      LDY #$08
E0B2   B1 22      LDA ($22),Y
E0B4   85 63      STA $63
E0B6   C8         INY
E0B7   B1 22      LDA ($22),Y
E0B9   85 65      STA $65
E0BB   4C E3 E0   JMP $E0E3
E0BE   A9 8B      LDA #$8B
E0C0   A0 00      LDY #$00
E0C2   20 A2 BB   JSR $BBA2
E0C5   A9 8D      LDA #$8D
E0C7   A0 E0      LDY #$E0
E0C9   20 28 BA   JSR $BA28
E0CC   A9 92      LDA #$92
E0CE   A0 E0      LDY #$E0
E0D0   20 67 B8   JSR $B867
E0D3   A6 65      LDX $65
E0D5   A5 62      LDA $62
E0D7   85 65      STA $65
E0D9   86 62      STX $62
E0DB   A6 63      LDX $63
E0DD   A5 64      LDA $64
E0DF   85 63      STA $63
E0E1   86 64      STX $64
E0E3   A9 00      LDA #$00
E0E5   85 66      STA $66
E0E7   A5 61      LDA $61
E0E9   85 70      STA $70
E0EB   A9 80      LDA #$80
E0ED   85 61      STA $61
E0EF   20 D7 B8   JSR $B8D7
E0F2   A2 8B      LDX #$8B
E0F4   A0 00      LDY #$00
E0F6   4C D4 BB   JMP $BBD4

; handle errors for direct I/O, calls from basic

E0F9   C9 F0      CMP #$F0
E0FB   D0 07      BNE $E104
E0FD   84 38      STY $38
E0FF   86 37      STX $37
E101   4C 63 A6   JMP $A663
E104   AA         TAX
E105   D0 02      BNE $E109
E107   A2 1E      LDX #$1E
E109   4C 37 A4   JMP $A437
E10C   20 D2 FF   JSR $FFD2
E10F   B0 E8      BCS $E0F9
E111   60         RTS
E112   20 CF FF   JSR $FFCF
E115   B0 E2      BCS $E0F9
E117   60         RTS
E118   20 AD E4   JSR $E4AD
E11B   B0 DC      BCS $E0F9
E11D   60         RTS
E11E   20 C6 FF   JSR $FFC6
E121   B0 D6      BCS $E0F9
E123   60         RTS
E124   20 E4 FF   JSR $FFE4
E127   B0 D0      BCS $E0F9
E129   60         RTS

; SYS command

E12A   20 8A AD   JSR $AD8A
E12D   20 F7 B7   JSR $B7F7
E130   A9 E1      LDA #$E1      ; low  E146
E132   48         PHA
E133   A9 46      LDA #$46      ; high E146
E135   48         PHA
E136   AD 0F 03   LDA $030F
E139   48         PHA
E13A   AD 0C 03   LDA $030C
E13D   AE 0D 03   LDX $030D
E140   AC 0E 03   LDY $030E
E143   28         PLP
E144   6C 14 00   JMP ($0014)
E147   08         PHP
E148   8D 0C 03   STA $030C
E14B   8E 0D 03   STX $030D
E14E   8C 0E 03   STY $030E
E151   68         PLA
E152   8D 0F 03   STA $030F
E155   60         RTS

; SAVE command

E156   20 D4 E1   JSR $E1D4
E159   A6 2D      LDX $2D
E15B   A4 2E      LDY $2E
E15D   A9 2B      LDA #$2B
E15F   20 D8 FF   JSR $FFD8
E162   B0 95      BCS $E0F9
E164   60         RTS

; VERIFY command

E165   A9 01      LDA #$01
E167   .BY $2C

; LOAD command

E168   A9 00      LDA #$00
E16A   85 0A      STA $0A
E16C   20 D4 E1   JSR $E1D4
E16F   A5 0A      LDA $0A
E171   A6 2B      LDX $2B
E173   A4 2C      LDY $2C
E175   20 D5 FF   JSR $FFD5
E178   B0 57      BCS $E1D1
E17A   A5 0A      LDA $0A
E17C   F0 17      BEQ $E195
E17E   A2 1C      LDX #$1C
E180   20 B7 FF   JSR $FFB7
E183   29 10      AND #$10
E185   D0 17      BNE $E19E
E187   A5 7A      LDA $7A
E189   C9 02      CMP #$02
E18B   F0 07      BEQ $E194
E18D   A9 64      LDA #$64
E18F   A0 A3      LDY #$A3
E191   4C 1E AB   JMP $AB1E
E194   60         RTS
E195   20 B7 FF   JSR $FFB7
E198   29 BF      AND #$BF
E19A   F0 05      BEQ $E1A1
E19C   A2 1D      LDX #$1D
E19E   4C 37 A4   JMP $A437
E1A1   A5 7B      LDA $7B
E1A3   C9 02      CMP #$02
E1A5   D0 0E      BNE $E1B5
E1A7   86 2D      STX $2D
E1A9   84 2E      STY $2E
E1AB   A9 76      LDA #$76
E1AD   A0 A3      LDY #$A3
E1AF   20 1E AB   JSR $AB1E
E1B2   4C 2A A5   JMP $A52A
E1B5   20 8E A6   JSR $A68E
E1B8   20 33 A5   JSR $A533
E1BB   4C 77 A6   JMP $A677

; OPEN command

E1BE   20 19 E2   JSR $E219
E1C1   20 C0 FF   JSR $FFC0
E1C4   B0 0B      BCS $E1D1
E1C6   60         RTS

; CLOSE command

E1C7   20 19 E2   JSR $E219
E1CA   A5 49      LDA $49
E1CC   20 C3 FF   JSR $FFC3
E1CF   90 C3      BCC $E194
E1D1   4C F9 E0   JMP $E0F9

; set parameters for load/verify/save

E1D4   A9 00      LDA #$00
E1D6   20 BD FF   JSR $FFBD
E1D9   A2 01      LDX #$01
E1DB   A0 00      LDY #$00
E1DD   20 BA FF   JSR $FFBA
E1E0   20 06 E2   JSR $E206
E1E3   20 57 E2   JSR $E257
E1E6   20 06 E2   JSR $E206
E1E9   20 00 E2   JSR $E200
E1EC   A0 00      LDY #$00
E1EE   86 49      STX $49
E1F0   20 BA FF   JSR $FFBA
E1F3   20 06 E2   JSR $E206
E1F6   20 00 E2   JSR $E200
E1F9   8A         TXA
E1FA   A8         TAY
E1FB   A6 49      LDX $49
E1FD   4C BA FF   JMP $FFBA

; skip comma and get integer in X

E200   20 0E E2   JSR $E20E
E203   4C 9E B7   JMP $B79E

; get character and check for end of line

E206   20 79 00   JSR $0079
E209   D0 02      BNE $E20D
E20B   68         PLA
E20C   68         PLA
E20D   60         RTS

; check for comma and skip it

E20E   20 FD AE   JSR $AEFD
E211   20 79 00   JSR $0079
E214   D0 F7      BNE $E20D
E216   4C 08 AF   JMP $AF08

; get open/close parameters

E219   A9 00      LDA #$00
E21B   20 BD FF   JSR $FFBD
E21E   20 11 E2   JSR $E211
E221   20 9E B7   JSR $B79E
E224   86 49      STX $49
E226   8A         TXA
E227   A2 01      LDX #$01
E229   A0 00      LDY #$00
E22B   20 BA FF   JSR $FFBA
E22E   20 06 E2   JSR $E206
E231   20 00 E2   JSR $E200
E234   86 4A      STX $4A
E236   A0 00      LDY #$00
E238   A5 49      LDA $49
E23A   E0 03      CPX #$03
E23C   90 01      BCC $E23F
E23E   88         DEY
E23F   20 BA FF   JSR $FFBA
E242   20 06 E2   JSR $E206
E245   20 00 E2   JSR $E200
E248   8A         TXA
E249   A8         TAY
E24A   A6 4A      LDX $4A
E24C   A5 49      LDA $49
E24E   20 BA FF   JSR $FFBA
E251   20 06 E2   JSR $E206
E254   20 0E E2   JSR $E20E
E257   20 9E AD   JSR $AD9E
E25A   20 A3 B6   JSR $B6A3
E25D   A6 22      LDX $22
E25F   A4 23      LDY $23
E261   4C BD FF   JMP $FFBD

; COS function

E264   A9 E0      LDA #$E0      ; low  E2E0
E266   A0 E2      LDY #$E2      ; high E2E0
E268   20 67 B8   JSR $B867

; SIN function

E26B   20 0C BC   JSR $BC0C
E26E   A9 E5      LDA #$E5      ; low  E2E5
E270   A0 E2      LDY #$E2      ; high E2E5
E272   A6 6E      LDX $6E
E274   20 07 BB   JSR $BB07
E277   20 0C BC   JSR $BC0C
E27A   20 CC BC   JSR $BCCC
E27D   A9 00      LDA #$00
E27F   85 6F      STA $6F
E281   20 53 B8   JSR $B853
E284   A9 EA      LDA #$EA      ; low  E2EA
E286   A0 E2      LDY #$E2      ; high E2EA
E288   20 50 B8   JSR $B850
E28B   A5 66      LDA $66
E28D   48         PHA
E28E   10 0D      BPL $E29D
E290   20 49 B8   JSR $B849
E293   A5 66      LDA $66
E295   30 09      BMI $E2A0
E297   A5 12      LDA $12
E299   49 FF      EOR #$FF
E29B   85 12      STA $12
E29D   20 B4 BF   JSR $BFB4
E2A0   A9 EA      LDA #$EA      ; low  E2EA
E2A2   A0 E2      LDY #$E2      ; high E2EA
E2A4   20 67 B8   JSR $B867
E2A7   68         PLA
E2A8   10 03      BPL $E2AD
E2AA   20 B4 BF   JSR $BFB4
E2AD   A9 EF      LDA #$EF
E2AF   A0 E2      LDY #$E2
E2B1   4C 43 E0   JMP $E043

; TAN function

E2B4   20 CA BB   JSR $BBCA
E2B7   A9 00      LDA #$00
E2B9   85 12      STA $12
E2BB   20 6B E2   JSR $E26B
E2BE   A2 4E      LDX #$4E      ; low  004E
E2C0   A0 00      LDY #$00      ; high 004E
E2C2   20 F6 E0   JSR $E0F6
E2C5   A9 57      LDA #$57      ; low  005F
E2C7   A0 00      LDY #$00      ; high 005F
E2C9   20 A2 BB   JSR $BBA2
E2CC   A9 00      LDA #$00
E2CE   85 66      STA $66
E2D0   A5 12      LDA $12
E2D2   20 DC E2   JSR $E2DC
E2D5   A9 4E      LDA #$4E      ; low  004E
E2D7   A0 00      LDY #$00      ; high 004E
E2D9   4C 0F BB   JMP $BB0F
E2DC   48         PHA
E2DD   4C 9D E2   JMP $E29D

; float numbers for SIN, COS and TAN

E2E0   .BY $81,$49,$0F,$DA,$A2  ; 0.5 * PI
E2E5   .BY $83,$49,$0F,$DA,$A2  ; 2 * PI
E2EA   .BY $7F,$00,$00,$00,$00  ; 0,25

; polynomial table

E2EF   .BY $05                  ; degree 6
E2F0   .BY $84,$E6,$1A,$2D,$1B
E2F5   .BY $86,$28,$07,$FB,$F8
E2FA   .BY $87,$99,$68,$89,$01
E2FF   .BY $87,$23,$35,$DF,$E1
E304   .BY $86,$A5,$5D,$E7,$28
E309   .BY $83,$49,$0F,$DA,$A2

; ATN function

E30E   A5 66      LDA $66
E310   48         PHA
E311   10 03      BPL $E316
E313   20 B4 BF   JSR $BFB4
E316   A5 61      LDA $61
E318   48         PHA
E319   C9 81      CMP #$81
E31B   90 07      BCC $E324
E31D   A9 BC      LDA #$BC      ; low  B9BC
E31F   A0 B9      LDY #$B9      ; high B9BC
E321   20 0F BB   JSR $BB0F
E324   A9 3E      LDA #$3E      ; low  E33E
E326   A0 E3      LDY #$E3      ; high E33E
E328   20 43 E0   JSR $E043
E32B   68         PLA
E32C   C9 81      CMP #$81
E32E   90 07      BCC $E337
E330   A9 E0      LDA #$E0      ; low  E2E0
E332   A0 E2      LDY #$E2      ; high E2E0
E334   20 50 B8   JSR $B850
E337   68         PLA
E338   10 03      BPL $E33D
E33A   4C B4 BF   JMP $BFB4
E33D   60         RTS

; float numbers for ATN, polynomial table

E33E   .BY $0B   ; degree 12
E33F   .BY $76,$B3,$83,$BD,$D3
E344   .BY $79,$1E,$F4,$A6,$F5
E349   .BY $7B,$83,$FC,$B0,$10
E34E   .BY $7C,$0C,$1F,$67,$CA
E353   .BY $7C,$DE,$53,$CB,$C1
E358   .BY $7D,$14,$64,$70,$4C
E35D   .BY $7D,$B7,$EA,$51,$7A
E362   .BY $7D,$63,$30,$88,$7E
E367   .BY $7E,$92,$44,$99,$3A
E36C   .BY $7E,$4C,$CC,$91,$C7
E371   .BY $7F,$AA,$AA,$AA,$13
E376   .BY $81,$00,$00,$00,$00

; warm start entry

E37B   20 CC FF   JSR $FFCC
E37E   A9 00      LDA #$00
E380   85 13      STA $13
E382   20 7A A6   JSR $A67A
E385   58         CLI
E386   A2 80      LDX #$80
E388   6C 00 03   JMP ($0300)   ; normally E38B

; handle error messages

E38B   8A         TXA
E38C   30 03      BMI $E391
E38E   4C 3A A4   JMP $A43A
E391   4C 74 A4   JMP $A474

; RESET routine

E394   20 53 E4   JSR $E453
E397   20 BF E3   JSR $E3BF
E39A   20 22 E4   JSR $E422
E39D   A2 FB      LDX #$FB
E39F   9A         TXS
E3A0   D0 E4      BNE $E386

; character fetch code for zero page $0073-$008F

E3A2   E6 7A      INC $7A
E3A4   D0 02      BNE $E3A8
E3A6   E6 7B      INC $7B
E3A8   AD 60 EA   LDA $EA60
E3AB   C9 3A      CMP #$3A      ; colon
E3AD   B0 0A      BCS $E3B9
E3AF   C9 20      CMP #$20      ; space
E3B1   F0 EF      BEQ $E3A2
E3B3   38         SEC
E3B4   E9 30      SBC #$30      ; 0
E3B6   38         SEC
E3B7   E9 D0      SBC #$D0
E3B9   60         RTS

; first RND seed value

E3BA   .BY $80,$4F,$C7,$52,$58

; initialisation of basic

E3BF   A9 4C      LDA #$4C
E3C1   85 54      STA $54
E3C3   8D 10 03   STA $0310
E3C6   A9 48      LDA #$48      ; low  B248
E3C8   A0 B2      LDY #$B2      ; high B248
E3CA   8D 11 03   STA $0311
E3CD   8C 12 03   STY $0312
E3D0   A9 91      LDA #$91      ; lowh B391
E3D2   A0 B3      LDY #$B3      ; high B391
E3D4   85 05      STA $05
E3D6   84 06      STY $06
E3D8   A9 AA      LDA #$AA      ; low  B1AA
E3DA   A0 B1      LDY #$B1      ; high B1AA
E3DC   85 03      STA $03
E3DE   84 04      STY $04
E3E0   A2 1C      LDX #$1C
E3E2   BD A2 E3   LDA $E3A2,X
E3E5   95 73      STA $73,X
E3E7   CA         DEX
E3E8   10 F8      BPL $E3E2
E3EA   A9 03      LDA #$03
E3EC   85 53      STA $53
E3EE   A9 00      LDA #$00
E3F0   85 68      STA $68
E3F2   85 13      STA $13
E3F4   85 18      STA $18
E3F6   A2 01      LDX #$01
E3F8   8E FD 01   STX $01FD
E3FB   8E FC 01   STX $01FC
E3FE   A2 19      LDX #$19
E400   86 16      STX $16
E402   38         SEC
E403   20 9C FF   JSR $FF9C
E406   86 2B      STX $2B
E408   84 2C      STY $2C
E40A   38         SEC
E40B   20 99 FF   JSR $FF99
E40E   86 37      STX $37
E410   84 38      STY $38
E412   86 33      STX $33
E414   84 34      STY $34
E416   A0 00      LDY #$00
E418   98         TYA
E419   91 2B      STA ($2B),Y
E41B   E6 2B      INC $2B
E41D   D0 02      BNE $E421
E41F   E6 2C      INC $2C
E421   60         RTS

; print BASIC start up messages

E422   A5 2B      LDA $2B
E424   A4 2C      LDY $2C
E426   20 08 A4   JSR $A408
E429   A9 73      LDA #$73      ; low  E473
E42B   A0 E4      LDY #$E4      ; high E473
E42D   20 1E AB   JSR $AB1E
E430   A5 37      LDA $37
E432   38         SEC
E433   E5 2B      SBC $2B
E435   AA         TAX
E436   A5 38      LDA $38
E438   E5 2C      SBC $2C
E43A   20 CD BD   JSR $BDCD
E43D   A9 60      LDA #$60      ; low  E460
E43F   A0 E4      LDY #$E4      ; high E460
E441   20 1E AB   JSR $AB1E
E444   4C 44 A6   JMP $A644

; vectors for $0300-$030B

E447   .WD $E38B
E449   .WD $A483
E44B   .WD $A57C
E44D   .WD $A71A
E44F   .WD $A7E4
E451   .WD $AE86

; initialise vectors

E453   A2 0B      LDX #$0B
E455   BD 47 E4   LDA $E447,X
E458   9D 00 03   STA $0300,X
E45B   CA         DEX
E45C   10 F7      BPL $E455
E45E   60         RTS

; startup messages

E45F   .BY $00

E460   .BY $20,$42,$41,$53,$49,$43   ; basic bytes free
E466   .BY $20,$42,$59,$54,$45,$53
E46C   .BY $20,$46,$52,$45,$45
E471   .BY $0D
E472   .BY $00

E473   .BY $93,$0D,$20,$20,$20       ; **** commodore 64 basic v2 ****
E478   .BY $20,$2A,$2A,$2A,$2A
E47D   .BY $20,$43,$4F,$4D,$4D,
E482   .BY $4F,$44,$4F,$52,$45
E487   .BY $20,$36,$34
E48A   .BY $20,$42,$41,$53,$49,$43
E490   .BY $20,$56,$32
E493   .BY $20,$2A,$2A,$2A,$2A
E498   .BY $0D,$0D

E49A   .BY $20,$36,$34,$4B           ; 64k ram system
E49E   .BY $20,$52,$41,$4D
E4A2   .BY $20,$53,$59,$53,$54,$45,$4D
E4A9   .BY $20,$20
E4AB   .BY $00
E4AC   .BY $81

; set output device

E4AD   48         PHA
E4AE   20 C9 FF   JSR $FFC9
E4B1   AA         TAX
E4B2   68         PLA
E4B3   90 01      BCC $E4B6
E4B5   8A         TXA
E4B6   60         RTS

; unused

E4B7   .BY $AA,$AA,$AA,$AA,$AA,$AA,$AA,$AA
E4BF   .BY $AA,$AA,$AA,$AA,$AA,$AA,$AA,$AA
E4C7   .BY $AA,$AA,$AA,$AA,$AA,$AA,$AA,$AA
E4CF   .BY $AA,$AA,$AA,$AA

E4D3   85 A9      STA $A9
E4D5   A9 01      LDA #$01
E4D7   85 AB      STA $AB
E4D9   60         RTS

; clear byte in color ram

E4DA   AD 86 02   LDA $0286
E4DD   91 F3      STA ($F3),Y
E4DF   60         RTS

; pause after finding a file on casette

E4E0   69 02      ADC #$02
E4E2   A4 91      LDY $91
E4E4   C8         INY
E4E5   D0 04      BNE $E4EB
E4E7   C5 A1      CMP $A1
E4E9   D0 F7      BNE $E4E2
E4EB   60         RTS

; baud rate factor table

E4EC   .WD $2619   ; 50
E4EE   .WD $1944   ; 75
E4F0   .WD $111A   ; 110
E4F2   .WD $0DE8   ; 134.5
E4F4   .WD $0C70   ; 150
E4F6   .WD $0606   ; 300
E4F8   .WD $02D1   ; 600
E4FA   .WD $0137   ; 1200
E4FC   .WD $00AE   ; 1800
E4FE   .WD $0069   ; 2400

; read base address of I/O device into XY

E500   A2 00      LDX #$00      ; low  DC00
E502   A0 DC      LDY #$DC      ; high DC00
E504   60         RTS

; read screen size

E505   A2 28      LDX #$28      ; 40 columns
E507   A0 19      LDY #$19      ; 25 rows
E509   60         RTS

; read/set XY cursor position

E50A   B0 07      BCS $E513
E50C   86 D6      STX $D6
E50E   84 D3      STY $D3
E510   20 6C E5   JSR $E56C
E513   A6 D6      LDX $D6
E515   A4 D3      LDY $D3
E517   60         RTS

; initialise screen and keyboard

E518   20 A0 E5   JSR $E5A0
E51B   A9 00      LDA #$00
E51D   8D 91 02   STA $0291
E520   85 CF      STA $CF
E522   A9 48      LDA #$48      ; low  EB48
E524   8D 8F 02   STA $028F
E527   A9 EB      LDA #$EB      ; high EB48
E529   8D 90 02   STA $0290
E52C   A9 0A      LDA #$0A
E52E   8D 89 02   STA $0289
E531   8D 8C 02   STA $028C
E534   A9 0E      LDA #$0E
E536   8D 86 02   STA $0286
E539   A9 04      LDA #$04
E53B   8D 8B 02   STA $028B
E53E   A9 0C      LDA #$0C
E540   85 CD      STA $CD
E542   85 CC      STA $CC
E544   AD 88 02   LDA $0288
E547   09 80      ORA #$80
E549   A8         TAY
E54A   A9 00      LDA #$00
E54C   AA         TAX
E54D   94 D9      STY $D9,X
E54F   18         CLC
E550   69 28      ADC #$28
E552   90 01      BCC $E555
E554   C8         INY
E555   E8         INX
E556   E0 1A      CPX #$1A
E558   D0 F3      BNE $E54D
E55A   A9 FF      LDA #$FF
E55C   95 D9      STA $D9,X
E55E   A2 18      LDX #$18
E560   20 FF E9   JSR $E9FF
E563   CA         DEX
E564   10 FA      BPL $E560
E566   A0 00      LDY #$00
E568   84 D3      STY $D3
E56A   84 D6      STY $D6

; set address of curent screen line

E56C   A6 D6      LDX $D6
E56E   A5 D3      LDA $D3
E570   B4 D9      LDY $D9,X
E572   30 08      BMI $E57C
E574   18         CLC
E575   69 28      ADC #$28
E577   85 D3      STA $D3
E579   CA         DEX
E57A   10 F4      BPL $E570
E57C   20 F0 E9   JSR $E9F0
E57F   A9 27      LDA #$27
E581   E8         INX
E582   B4 D9      LDY $D9,X
E584   30 06      BMI $E58C
E586   18         CLC
E587   69 28      ADC #$28
E589   E8         INX
E58A   10 F6      BPL $E582
E58C   85 D5      STA $D5
E58E   4C 24 EA   JMP $EA24
E591   E4 C9      CPX $C9
E593   F0 03      BEQ $E598
E595   4C ED E6   JMP $E6ED
E598   60         RTS
E599   EA         NOP

; this code is unused by the rom, no jumps to this location!

E59A   20 A0 E5   JSR $E5A0
E59D   4C 66 E5   JMP $E566

; initialise vic chip

E5A0   A9 03      LDA #$03
E5A2   85 9A      STA $9A
E5A4   A9 00      LDA #$00
E5A6   85 99      STA $99
E5A8   A2 2F      LDX #$2F
E5AA   BD B8 EC   LDA $ECB8,X
E5AD   9D FF CF   STA $CFFF,X
E5B0   CA         DEX
E5B1   D0 F7      BNE $E5AA
E5B3   60         RTS

; get character from keyboard buffer

E5B4   AC 77 02   LDY $0277
E5B7   A2 00      LDX #$00
E5B9   BD 78 02   LDA $0278,X
E5BC   9D 77 02   STA $0277,X
E5BF   E8         INX
E5C0   E4 C6      CPX $C6
E5C2   D0 F5      BNE $E5B9
E5C4   C6 C6      DEC $C6
E5C6   98         TYA
E5C7   58         CLI
E5C8   18         CLC
E5C9   60         RTS

; wait for return for keyboard

E5CA   20 16 E7   JSR $E716
E5CD   A5 C6      LDA $C6
E5CF   85 CC      STA $CC
E5D1   8D 92 02   STA $0292
E5D4   F0 F7      BEQ $E5CD
E5D6   78         SEI
E5D7   A5 CF      LDA $CF
E5D9   F0 0C      BEQ $E5E7
E5DB   A5 CE      LDA $CE
E5DD   AE 87 02   LDX $0287
E5E0   A0 00      LDY #$00
E5E2   84 CF      STY $CF
E5E4   20 13 EA   JSR $EA13
E5E7   20 B4 E5   JSR $E5B4
E5EA   C9 83      CMP #$83
E5EC   D0 10      BNE $E5FE
E5EE   A2 09      LDX #$09
E5F0   78         SEI
E5F1   86 C6      STX $C6
E5F3   BD E6 EC   LDA $ECE6,X
E5F6   9D 76 02   STA $0276,X
E5F9   CA         DEX
E5FA   D0 F7      BNE $E5F3
E5FC   F0 CF      BEQ $E5CD
E5FE   C9 0D      CMP #$0D
E600   D0 C8      BNE $E5CA
E602   A4 D5      LDY $D5
E604   84 D0      STY $D0
E606   B1 D1      LDA ($D1),Y
E608   C9 20      CMP #$20
E60A   D0 03      BNE $E60F
E60C   88         DEY
E60D   D0 F7      BNE $E606
E60F   C8         INY
E610   84 C8      STY $C8
E612   A0 00      LDY #$00
E614   8C 92 02   STY $0292
E617   84 D3      STY $D3
E619   84 D4      STY $D4
E61B   A5 C9      LDA $C9
E61D   30 1B      BMI $E63A
E61F   A6 D6      LDX $D6
E621   20 91 E5   JSR $E591
E624   E4 C9      CPX $C9
E626   D0 12      BNE $E63A
E628   A5 CA      LDA $CA
E62A   85 D3      STA $D3
E62C   C5 C8      CMP $C8
E62E   90 0A      BCC $E63A
E630   B0 2B      BCS $E65D

; get character from device 0 or 3

E632   98         TYA
E633   48         PHA
E634   8A         TXA
E635   48         PHA
E636   A5 D0      LDA $D0
E638   F0 93      BEQ $E5CD

; get character from current screen line

E63A   A4 D3      LDY $D3
E63C   B1 D1      LDA ($D1),Y
E63E   85 D7      STA $D7
E640   29 3F      AND #$3F
E642   06 D7      ASL $D7
E644   24 D7      BIT $D7
E646   10 02      BPL $E64A
E648   09 80      ORA #$80
E64A   90 04      BCC $E650
E64C   A6 D4      LDX $D4
E64E   D0 04      BNE $E654
E650   70 02      BVS $E654
E652   09 40      ORA #$40
E654   E6 D3      INC $D3
E656   20 84 E6   JSR $E684
E659   C4 C8      CPY $C8
E65B   D0 17      BNE $E674
E65D   A9 00      LDA #$00
E65F   85 D0      STA $D0
E661   A9 0D      LDA #$0D
E663   A6 99      LDX $99
E665   E0 03      CPX #$03
E667   F0 06      BEQ $E66F
E669   A6 9A      LDX $9A
E66B   E0 03      CPX #$03
E66D   F0 03      BEQ $E672
E66F   20 16 E7   JSR $E716
E672   A9 0D      LDA #$0D
E674   85 D7      STA $D7
E676   68         PLA
E677   AA         TAX
E678   68         PLA
E679   A8         TAY
E67A   A5 D7      LDA $D7
E67C   C9 DE      CMP #$DE      ; screen PI code
E67E   D0 02      BNE $E682
E680   A9 FF      LDA #$FF      ; petscii PI code
E682   18         CLC
E683   60         RTS

; check for quote mark and set flag

E684   C9 22      CMP #$22      ; quote mark
E686   D0 08      BNE $E690
E688   A5 D4      LDA $D4
E68A   49 01      EOR #$01
E68C   85 D4      STA $D4
E68E   A9 22      LDA #$22      ; quote mark
E690   60         RTS

; fill screen at current position

E691   09 40      ORA #$40
E693   A6 C7      LDX $C7
E695   F0 02      BEQ $E699
E697   09 80      ORA #$80
E699   A6 D8      LDX $D8
E69B   F0 02      BEQ $E69F
E69D   C6 D8      DEC $D8
E69F   AE 86 02   LDX $0286
E6A2   20 13 EA   JSR $EA13
E6A5   20 B6 E6   JSR $E6B6

; return from output to the screen

E6A8   68         PLA
E6A9   A8         TAY
E6AA   A5 D8      LDA $D8
E6AC   F0 02      BEQ $E6B0
E6AE   46 D4      LSR $D4
E6B0   68         PLA
E6B1   AA         TAX
E6B2   68         PLA
E6B3   18         CLC
E6B4   58         CLI
E6B5   60         RTS

; get/insert new line

E6B6   20 B3 E8   JSR $E8B3
E6B9   E6 D3      INC $D3
E6BB   A5 D5      LDA $D5
E6BD   C5 D3      CMP $D3
E6BF   B0 3F      BCS $E700
E6C1   C9 4F      CMP #$4F
E6C3   F0 32      BEQ $E6F7
E6C5   AD 92 02   LDA $0292
E6C8   F0 03      BEQ $E6CD
E6CA   4C 67 E9   JMP $E967
E6CD   A6 D6      LDX $D6
E6CF   E0 19      CPX #$19
E6D1   90 07      BCC $E6DA
E6D3   20 EA E8   JSR $E8EA
E6D6   C6 D6      DEC $D6
E6D8   A6 D6      LDX $D6
E6DA   16 D9      ASL $D9,X
E6DC   56 D9      LSR $D9,X
E6DE   E8         INX
E6DF   B5 D9      LDA $D9,X
E6E1   09 80      ORA #$80
E6E3   95 D9      STA $D9,X
E6E5   CA         DEX
E6E6   A5 D5      LDA $D5
E6E8   18         CLC
E6E9   69 28      ADC #$28
E6EB   85 D5      STA $D5
E6ED   B5 D9      LDA $D9,X
E6EF   30 03      BMI $E6F4
E6F1   CA         DEX
E6F2   D0 F9      BNE $E6ED
E6F4   4C F0 E9   JMP $E9F0
E6F7   C6 D6      DEC $D6
E6F9   20 7C E8   JSR $E87C
E6FC   A9 00      LDA #$00
E6FE   85 D3      STA $D3
E700   60         RTS

; move backwards over a line boundary

E701   A6 D6      LDX $D6
E703   D0 06      BNE $E70B
E705   86 D3      STX $D3
E707   68         PLA
E708   68         PLA
E709   D0 9D      BNE $E6A8
E70B   CA         DEX
E70C   86 D6      STX $D6
E70E   20 6C E5   JSR $E56C
E711   A4 D5      LDY $D5
E713   84 D3      STY $D3
E715   60         RTS

; put a character to screen

E716   48         PHA
E717   85 D7      STA $D7
E719   8A         TXA
E71A   48         PHA
E71B   98         TYA
E71C   48         PHA
E71D   A9 00      LDA #$00
E71F   85 D0      STA $D0
E721   A4 D3      LDY $D3
E723   A5 D7      LDA $D7
E725   10 03      BPL $E72A
E727   4C D4 E7   JMP $E7D4
E72A   C9 0D      CMP #$0D      ; return code
E72C   D0 03      BNE $E731
E72E   4C 91 E8   JMP $E891
E731   C9 20      CMP #$20
E733   90 10      BCC $E745
E735   C9 60      CMP #$60
E737   90 04      BCC $E73D
E739   29 DF      AND #$DF
E73B   D0 02      BNE $E73F
E73D   29 3F      AND #$3F
E73F   20 84 E6   JSR $E684
E742   4C 93 E6   JMP $E693
E745   A6 D8      LDX $D8
E747   F0 03      BEQ $E74C
E749   4C 97 E6   JMP $E697
E74C   C9 14      CMP #$14      ; delete code
E74E   D0 2E      BNE $E77E
E750   98         TYA
E751   D0 06      BNE $E759
E753   20 01 E7   JSR $E701
E756   4C 73 E7   JMP $E773
E759   20 A1 E8   JSR $E8A1
E75C   88         DEY
E75D   84 D3      STY $D3
E75F   20 24 EA   JSR $EA24
E762   C8         INY
E763   B1 D1      LDA ($D1),Y
E765   88         DEY
E766   91 D1      STA ($D1),Y
E768   C8         INY
E769   B1 F3      LDA ($F3),Y
E76B   88         DEY
E76C   91 F3      STA ($F3),Y
E76E   C8         INY
E76F   C4 D5      CPY $D5
E771   D0 EF      BNE $E762
E773   A9 20      LDA #$20      ; space
E775   91 D1      STA ($D1),Y
E777   AD 86 02   LDA $0286
E77A   91 F3      STA ($F3),Y
E77C   10 4D      BPL $E7CB
E77E   A6 D4      LDX $D4
E780   F0 03      BEQ $E785
E782   4C 97 E6   JMP $E697
E785   C9 12      CMP #$12      ;  reverse code
E787   D0 02      BNE $E78B
E789   85 C7      STA $C7
E78B   C9 13      CMP #$13      ; home code
E78D   D0 03      BNE $E792
E78F   20 66 E5   JSR $E566
E792   C9 1D      CMP #$1D      ; csr right
E794   D0 17      BNE $E7AD
E796   C8         INY
E797   20 B3 E8   JSR $E8B3
E79A   84 D3      STY $D3
E79C   88         DEY
E79D   C4 D5      CPY $D5
E79F   90 09      BCC $E7AA
E7A1   C6 D6      DEC $D6
E7A3   20 7C E8   JSR $E87C
E7A6   A0 00      LDY #$00
E7A8   84 D3      STY $D3
E7AA   4C A8 E6   JMP $E6A8
E7AD   C9 11      CMP #$11      ; csr down
E7AF   D0 1D      BNE $E7CE
E7B1   18         CLC
E7B2   98         TYA
E7B3   69 28      ADC #$28
E7B5   A8         TAY
E7B6   E6 D6      INC $D6
E7B8   C5 D5      CMP $D5
E7BA   90 EC      BCC $E7A8
E7BC   F0 EA      BEQ $E7A8
E7BE   C6 D6      DEC $D6
E7C0   E9 28      SBC #$28
E7C2   90 04      BCC $E7C8
E7C4   85 D3      STA $D3
E7C6   D0 F8      BNE $E7C0
E7C8   20 7C E8   JSR $E87C
E7CB   4C A8 E6   JMP $E6A8
E7CE   20 CB E8   JSR $E8CB
E7D1   4C 44 EC   JMP $EC44

; put shifted chars to screen

E7D4   29 7F      AND #$7F      ; remove shift bit
E7D6   C9 7F      CMP #$7F      ; code for PI
E7D8   D0 02      BNE $E7DC
E7DA   A9 5E      LDA #$5E      ; screen PI
E7DC   C9 20      CMP #$20
E7DE   90 03      BCC $E7E3
E7E0   4C 91 E6   JMP $E691
E7E3   C9 0D      CMP #$0D      ; shift return
E7E5   D0 03      BNE $E7EA
E7E7   4C 91 E8   JMP $E891
E7EA   A6 D4      LDX $D4
E7EC   D0 3F      BNE $E82D
E7EE   C9 14      CMP #$14      ; insert
E7F0   D0 37      BNE $E829
E7F2   A4 D5      LDY $D5
E7F4   B1 D1      LDA ($D1),Y
E7F6   C9 20      CMP #$20
E7F8   D0 04      BNE $E7FE
E7FA   C4 D3      CPY $D3
E7FC   D0 07      BNE $E805
E7FE   C0 4F      CPY #$4F
E800   F0 24      BEQ $E826
E802   20 65 E9   JSR $E965
E805   A4 D5      LDY $D5
E807   20 24 EA   JSR $EA24
E80A   88         DEY
E80B   B1 D1      LDA ($D1),Y
E80D   C8         INY
E80E   91 D1      STA ($D1),Y
E810   88         DEY
E811   B1 F3      LDA ($F3),Y
E813   C8         INY
E814   91 F3      STA ($F3),Y
E816   88         DEY
E817   C4 D3      CPY $D3
E819   D0 EF      BNE $E80A
E81B   A9 20      LDA #$20
E81D   91 D1      STA ($D1),Y
E81F   AD 86 02   LDA $0286
E822   91 F3      STA ($F3),Y
E824   E6 D8      INC $D8
E826   4C A8 E6   JMP $E6A8
E829   A6 D8      LDX $D8
E82B   F0 05      BEQ $E832
E82D   09 40      ORA #$40
E82F   4C 97 E6   JMP $E697
E832   C9 11      CMP #$11      ; csr up
E834   D0 16      BNE $E84C
E836   A6 D6      LDX $D6
E838   F0 37      BEQ $E871
E83A   C6 D6      DEC $D6
E83C   A5 D3      LDA $D3
E83E   38         SEC
E83F   E9 28      SBC #$28
E841   90 04      BCC $E847
E843   85 D3      STA $D3
E845   10 2A      BPL $E871
E847   20 6C E5   JSR $E56C
E84A   D0 25      BNE $E871
E84C   C9 12      CMP #$12      ; reverse off
E84E   D0 04      BNE $E854
E850   A9 00      LDA #$00
E852   85 C7      STA $C7
E854   C9 1D      CMP #$1D      ; csr left
E856   D0 12      BNE $E86A
E858   98         TYA
E859   F0 09      BEQ $E864
E85B   20 A1 E8   JSR $E8A1
E85E   88         DEY
E85F   84 D3      STY $D3
E861   4C A8 E6   JMP $E6A8
E864   20 01 E7   JSR $E701
E867   4C A8 E6   JMP $E6A8
E86A   C9 13      CMP #$13      ; clr code
E86C   D0 06      BNE $E874
E86E   20 44 E5   JSR $E544
E871   4C A8 E6   JMP $E6A8
E874   09 80      ORA #$80
E876   20 CB E8   JSR $E8CB
E879   4C 4F EC   JMP $EC4F

; set next line number

E87C   46 C9      LSR $C9
E87E   A6 D6      LDX $D6
E880   E8         INX
E881   E0 19      CPX #$19
E883   D0 03      BNE $E888
E885   20 EA E8   JSR $E8EA
E888   B5 D9      LDA $D9,X
E88A   10 F4      BPL $E880
E88C   86 D6      STX $D6
E88E   4C 6C E5   JMP $E56C

; action for return

E891   A2 00      LDX #$00
E893   86 D8      STX $D8
E895   86 C7      STX $C7
E897   86 D4      STX $D4
E899   86 D3      STX $D3
E89B   20 7C E8   JSR $E87C
E89E   4C A8 E6   JMP $E6A8

; move cursor to previous line if at start of line

E8A1   A2 02      LDX #$02
E8A3   A9 00      LDA #$00
E8A5   C5 D3      CMP $D3
E8A7   F0 07      BEQ $E8B0
E8A9   18         CLC
E8AA   69 28      ADC #$28
E8AC   CA         DEX
E8AD   D0 F6      BNE $E8A5
E8AF   60         RTS
E8B0   C6 D6      DEC $D6
E8B2   60         RTS

; move cursor to next line if at end of line

E8B3   A2 02      LDX #$02
E8B5   A9 27      LDA #$27
E8B7   C5 D3      CMP $D3
E8B9   F0 07      BEQ $E8C2
E8BB   18         CLC
E8BC   69 28      ADC #$28
E8BE   CA         DEX
E8BF   D0 F6      BNE $E8B7
E8C1   60         RTS
E8C2   A6 D6      LDX $D6
E8C4   E0 19      CPX #$19
E8C6   F0 02      BEQ $E8CA
E8C8   E6 D6      INC $D6
E8CA   60         RTS

; check for color change codes

E8CB   A2 0F      LDX #$0F
E8CD   DD DA E8   CMP $E8DA,X
E8D0   F0 04      BEQ $E8D6
E8D2   CA         DEX
E8D3   10 F8      BPL $E8CD
E8D5   60         RTS
E8D6   8E 86 02   STX $0286
E8D9   60         RTS

; color key codes

E8DA   .BY $90,$05,$1C,$9F,$9C,$1E,$1F,$9E
E8E2   .BY $81,$95,$96,$97,$98,$99,$9A,$9B

; scroll screen

E8EA   A5 AC      LDA $AC
E8EC   48         PHA
E8ED   A5 AD      LDA $AD
E8EF   48         PHA
E8F0   A5 AE      LDA $AE
E8F2   48         PHA
E8F3   A5 AF      LDA $AF
E8F5   48         PHA
E8F6   A2 FF      LDX #$FF
E8F8   C6 D6      DEC $D6
E8FA   C6 C9      DEC $C9
E8FC   CE A5 02   DEC $02A5
E8FF   E8         INX
E900   20 F0 E9   JSR $E9F0
E903   E0 18      CPX #$18
E905   B0 0C      BCS $E913
E907   BD F1 EC   LDA $ECF1,X
E90A   85 AC      STA $AC
E90C   B5 DA      LDA $DA,X
E90E   20 C8 E9   JSR $E9C8
E911   30 EC      BMI $E8FF
E913   20 FF E9   JSR $E9FF
E916   A2 00      LDX #$00
E918   B5 D9      LDA $D9,X
E91A   29 7F      AND #$7F
E91C   B4 DA      LDY $DA,X
E91E   10 02      BPL $E922
E920   09 80      ORA #$80
E922   95 D9      STA $D9,X
E924   E8         INX
E925   E0 18      CPX #$18
E927   D0 EF      BNE $E918
E929   A5 F1      LDA $F1
E92B   09 80      ORA #$80
E92D   85 F1      STA $F1
E92F   A5 D9      LDA $D9
E931   10 C3      BPL $E8F6
E933   E6 D6      INC $D6
E935   EE A5 02   INC $02A5
E938   A9 7F      LDA #$7F
E93A   8D 00 DC   STA $DC00
E93D   AD 01 DC   LDA $DC01
E940   C9 FB      CMP #$FB
E942   08         PHP
E943   A9 7F      LDA #$7F
E945   8D 00 DC   STA $DC00
E948   28         PLP
E949   D0 0B      BNE $E956
E94B   A0 00      LDY #$00
E94D   EA         NOP
E94E   CA         DEX
E94F   D0 FC      BNE $E94D
E951   88         DEY
E952   D0 F9      BNE $E94D
E954   84 C6      STY $C6
E956   A6 D6      LDX $D6
E958   68         PLA
E959   85 AF      STA $AF
E95B   68         PLA
E95C   85 AE      STA $AE
E95E   68         PLA
E95F   85 AD      STA $AD
E961   68         PLA
E962   85 AC      STA $AC
E964   60         RTS

; insert blank line in screen

E965   A6 D6      LDX $D6
E967   E8         INX
E968   B5 D9      LDA $D9,X
E96A   10 FB      BPL $E967
E96C   8E A5 02   STX $02A5
E96F   E0 18      CPX #$18
E971   F0 0E      BEQ $E981
E973   90 0C      BCC $E981
E975   20 EA E8   JSR $E8EA
E978   AE A5 02   LDX $02A5
E97B   CA         DEX
E97C   C6 D6      DEC $D6
E97E   4C DA E6   JMP $E6DA
E981   A5 AC      LDA $AC
E983   48         PHA
E984   A5 AD      LDA $AD
E986   48         PHA
E987   A5 AE      LDA $AE
E989   48         PHA
E98A   A5 AF      LDA $AF
E98C   48         PHA
E98D   A2 19      LDX #$19
E98F   CA         DEX
E990   20 F0 E9   JSR $E9F0
E993   EC A5 02   CPX $02A5
E996   90 0E      BCC $E9A6
E998   F0 0C      BEQ $E9A6
E99A   BD EF EC   LDA $ECEF,X
E99D   85 AC      STA $AC
E99F   B5 D8      LDA $D8,X
E9A1   20 C8 E9   JSR $E9C8
E9A4   30 E9      BMI $E98F
E9A6   20 FF E9   JSR $E9FF
E9A9   A2 17      LDX #$17
E9AB   EC A5 02   CPX $02A5
E9AE   90 0F      BCC $E9BF
E9B0   B5 DA      LDA $DA,X
E9B2   29 7F      AND #$7F
E9B4   B4 D9      LDY $D9,X
E9B6   10 02      BPL $E9BA
E9B8   09 80      ORA #$80
E9BA   95 DA      STA $DA,X
E9BC   CA         DEX
E9BD   D0 EC      BNE $E9AB
E9BF   AE A5 02   LDX $02A5
E9C2   20 DA E6   JSR $E6DA
E9C5   4C 58 E9   JMP $E958

; move one screen line

E9C8   29 03      AND #$03
E9CA   0D 88 02   ORA $0288
E9CD   85 AD      STA $AD
E9CF   20 E0 E9   JSR $E9E0
E9D2   A0 27      LDY #$27
E9D4   B1 AC      LDA ($AC),Y
E9D6   91 D1      STA ($D1),Y
E9D8   B1 AE      LDA ($AE),Y
E9DA   91 F3      STA ($F3),Y
E9DC   88         DEY
E9DD   10 F5      BPL $E9D4
E9DF   60         RTS

; set color and screen addresses

E9E0   20 24 EA   JSR $EA24
E9E3   A5 AC      LDA $AC
E9E5   85 AE      STA $AE
E9E7   A5 AD      LDA $AD
E9E9   29 03      AND #$03
E9EB   09 D8      ORA #$D8
E9ED   85 AF      STA $AF
E9EF   60         RTS

; fetch screen addresses

E9F0   BD F0 EC   LDA $ECF0,X
E9F3   85 D1      STA $D1
E9F5   B5 D9      LDA $D9,X
E9F7   29 03      AND #$03
E9F9   0D 88 02   ORA $0288
E9FC   85 D2      STA $D2
E9FE   60         RTS

; clear one screen line

E9FF   A0 27      LDY #$27
EA01   20 F0 E9   JSR $E9F0
EA04   20 24 EA   JSR $EA24
EA07   20 DA E4   JSR $E4DA
EA0A   A9 20      LDA #$20
EA0C   91 D1      STA ($D1),Y
EA0E   88         DEY
EA0F   10 F6      BPL $EA07
EA11   60         RTS
EA12   EA         NOP

; set cursor flash timing and color memory addresses

EA13   A8         TAY
EA14   A9 02      LDA #$02
EA16   85 CD      STA $CD
EA18   20 24 EA   JSR $EA24
EA1B   98         TYA

; put a char on the screen

EA1C   A4 D3      LDY $D3
EA1E   91 D1      STA ($D1),Y
EA20   8A         TXA
EA21   91 F3      STA ($F3),Y
EA23   60         RTS

; set color memory adress parallel to screen

EA24   A5 D1      LDA $D1
EA26   85 F3      STA $F3
EA28   A5 D2      LDA $D2
EA2A   29 03      AND #$03
EA2C   09 D8      ORA #$D8
EA2E   85 F4      STA $F4
EA30   60         RTS

; normal IRQ interrupt

EA31   20 EA FF   JSR $FFEA     ; do clock
EA34   A5 CC      LDA $CC       ; flash cursor
EA36   D0 29      BNE $EA61
EA38   C6 CD      DEC $CD
EA3A   D0 25      BNE $EA61
EA3C   A9 14      LDA #$14
EA3E   85 CD      STA $CD
EA40   A4 D3      LDY $D3
EA42   46 CF      LSR $CF
EA44   AE 87 02   LDX $0287
EA47   B1 D1      LDA ($D1),Y
EA49   B0 11      BCS $EA5C
EA4B   E6 CF      INC $CF
EA4D   85 CE      STA $CE
EA4F   20 24 EA   JSR $EA24
EA52   B1 F3      LDA ($F3),Y
EA54   8D 87 02   STA $0287
EA57   AE 86 02   LDX $0286
EA5A   A5 CE      LDA $CE
EA5C   49 80      EOR #$80
EA5E   20 1C EA   JSR $EA1C     ; display cursor
EA61   A5 01      LDA $01       ; checl cassette sense
EA63   29 10      AND #$10
EA65   F0 0A      BEQ $EA71
EA67   A0 00      LDY #$00
EA69   84 C0      STY $C0
EA6B   A5 01      LDA $01
EA6D   09 20      ORA #$20
EA6F   D0 08      BNE $EA79
EA71   A5 C0      LDA $C0
EA73   D0 06      BNE $EA7B
EA75   A5 01      LDA $01
EA77   29 1F      AND #$1F
EA79   85 01      STA $01
EA7B   20 87 EA   JSR $EA87     ; scan keyboard
EA7E   AD 0D DC   LDA $DC0D
EA81   68         PLA
EA82   A8         TAY
EA83   68         PLA
EA84   AA         TAX
EA85   68         PLA
EA86   40         RTI

; scan keyboard

EA87   A9 00      LDA #$00
EA89   8D 8D 02   STA $028D
EA8C   A0 40      LDY #$40
EA8E   84 CB      STY $CB
EA90   8D 00 DC   STA $DC00
EA93   AE 01 DC   LDX $DC01
EA96   E0 FF      CPX #$FF
EA98   F0 61      BEQ $EAFB
EA9A   A8         TAY
EA9B   A9 81      LDA #$81
EA9D   85 F5      STA $F5
EA9F   A9 EB      LDA #$EB
EAA1   85 F6      STA $F6
EAA3   A9 FE      LDA #$FE
EAA5   8D 00 DC   STA $DC00
EAA8   A2 08      LDX #$08
EAAA   48         PHA
EAAB   AD 01 DC   LDA $DC01
EAAE   CD 01 DC   CMP $DC01
EAB1   D0 F8      BNE $EAAB
EAB3   4A         LSR
EAB4   B0 16      BCS $EACC
EAB6   48         PHA
EAB7   B1 F5      LDA ($F5),Y
EAB9   C9 05      CMP #$05
EABB   B0 0C      BCS $EAC9
EABD   C9 03      CMP #$03
EABF   F0 08      BEQ $EAC9
EAC1   0D 8D 02   ORA $028D
EAC4   8D 8D 02   STA $028D
EAC7   10 02      BPL $EACB
EAC9   84 CB      STY $CB
EACB   68         PLA
EACC   C8         INY
EACD   C0 41      CPY #$41
EACF   B0 0B      BCS $EADC
EAD1   CA         DEX
EAD2   D0 DF      BNE $EAB3
EAD4   38         SEC
EAD5   68         PLA
EAD6   2A         ROL
EAD7   8D 00 DC   STA $DC00
EADA   D0 CC      BNE $EAA8
EADC   68         PLA
EADD   6C 8F 02   JMP ($028F)
EAE0   A4 CB      LDY $CB
EAE2   B1 F5      LDA ($F5),Y
EAE4   AA         TAX
EAE5   C4 C5      CPY $C5
EAE7   F0 07      BEQ $EAF0
EAE9   A0 10      LDY #$10
EAEB   8C 8C 02   STY $028C
EAEE   D0 36      BNE $EB26
EAF0   29 7F      AND #$7F
EAF2   2C 8A 02   BIT $028A
EAF5   30 16      BMI $EB0D
EAF7   70 49      BVS $EB42
EAF9   C9 7F      CMP #$7F
EAFB   F0 29      BEQ $EB26
EAFD   C9 14      CMP #$14      ; delete
EAFF   F0 0C      BEQ $EB0D
EB01   C9 20      CMP #$20      ; space
EB03   F0 08      BEQ $EB0D
EB05   C9 1D      CMP #$1D      ; csr right/left
EB07   F0 04      BEQ $EB0D
EB09   C9 11      CMP #$11      ; csr up/down
EB0B   D0 35      BNE $EB42
EB0D   AC 8C 02   LDY $028C
EB10   F0 05      BEQ $EB17
EB12   CE 8C 02   DEC $028C
EB15   D0 2B      BNE $EB42
EB17   CE 8B 02   DEC $028B
EB1A   D0 26      BNE $EB42
EB1C   A0 04      LDY #$04
EB1E   8C 8B 02   STY $028B
EB21   A4 C6      LDY $C6
EB23   88         DEY
EB24   10 1C      BPL $EB42
EB26   A4 CB      LDY $CB
EB28   84 C5      STY $C5
EB2A   AC 8D 02   LDY $028D
EB2D   8C 8E 02   STY $028E
EB30   E0 FF      CPX #$FF
EB32   F0 0E      BEQ $EB42
EB34   8A         TXA
EB35   A6 C6      LDX $C6
EB37   EC 89 02   CPX $0289
EB3A   B0 06      BCS $EB42
EB3C   9D 77 02   STA $0277,X
EB3F   E8         INX
EB40   86 C6      STX $C6
EB42   A9 7F      LDA #$7F
EB44   8D 00 DC   STA $DC00
EB47   60         RTS
EB48   AD 8D 02   LDA $028D
EB4B   C9 03      CMP #$03
EB4D   D0 15      BNE $EB64
EB4F   CD 8E 02   CMP $028E
EB52   F0 EE      BEQ $EB42
EB54   AD 91 02   LDA $0291
EB57   30 1D      BMI $EB76
EB59   AD 18 D0   LDA $D018
EB5C   49 02      EOR #$02
EB5E   8D 18 D0   STA $D018
EB61   4C 76 EB   JMP $EB76

; select keyboard table

EB64   0A         ASL
EB65   C9 08      CMP #$08
EB67   90 02      BCC $EB6B
EB69   A9 06      LDA #$06
EB6B   AA         TAX
EB6C   BD 79 EB   LDA $EB79,X
EB6F   85 F5      STA $F5
EB71   BD 7A EB   LDA $EB7A,X
EB74   85 F6      STA $F6
EB76   4C E0 EA   JMP $EAE0

; table addresses

EB79   .WD $EB81   ; standard
EB7B   .WD $EBC2   ; shift
EB7D   .WD $EC03   ; commodore key
EB7F   .WD $EC78   ; control

; standard keyboard table

EB81   .BY $14,$0D,$1D,$88,$85,$86,$87,$11
EB89   .BY $33,$57,$41,$34,$5A,$53,$45,$01
EB91   .BY $35,$52,$44,$36,$43,$46,$54,$58
EB99   .BY $37,$59,$47,$38,$42,$48,$55,$56
EBA1   .BY $39,$49,$4A,$30,$4D,$4B,$4F,$4E
EBA9   .BY $2B,$50,$4C,$2D,$2E,$3A,$40,$2C
EBB1   .BY $5C,$2A,$3B,$13,$01,$3D,$5E,$2F
EBB9   .BY $31,$5F,$04,$32,$20,$02,$51,$03
EBC1   .BY $FF

; shift keyboard table

EBC2   .BY $94,$8D,$9D,$8C,$89,$8A,$8B,$91
EBCA   .BY $23,$D7,$C1,$24,$DA,$D3,$C5,$01
EBD2   .BY $25,$D2,$C4,$26,$C3,$C6,$D4,$D8
EBDA   .BY $27,$D9,$C7,$28,$C2,$C8,$D5,$D6
EBE2   .BY $29,$C9,$CA,$30,$CD,$CB,$CF,$CE
EBEA   .BY $DB,$D0,$CC,$DD,$3E,$5B,$BA,$3C
EBF2   .BY $A9,$C0,$5D,$93,$01,$3D,$DE,$3F
EBFA   .BY $21,$5F,$04,$22,$A0,$02,$D1,$83
EC02   .BY $FF

; commodore key keyboard table

EC03   .BY $94,$8D,$9D,$8C,$89,$8A,$8B,$91
EC0B   .BY $96,$B3,$B0,$97,$AD,$AE,$B1,$01
EC13   .BY $98,$B2,$AC,$99,$BC,$BB,$A3,$BD
EC1B   .BY $9A,$B7,$A5,$9B,$BF,$B4,$B8,$BE
EC23   .BY $29,$A2,$B5,$30,$A7,$A1,$B9,$AA
EC2B   .BY $A6,$AF,$B6,$DC,$3E,$5B,$A4,$3C
EC33   .BY $A8,$DF,$5D,$93,$01,$3D,$DE,$3F
EC3B   .BY $81,$5F,$04,$95,$A0,$02,$AB,$83
EC43   .BY $FF

; check for special petscii codes

EC44   C9 0E      CMP #$0E
EC46   D0 07      BNE $EC4F
EC48   AD 18 D0   LDA $D018
EC4B   09 02      ORA #$02
EC4D   D0 09      BNE $EC58
EC4F   C9 8E      CMP #$8E
EC51   D0 0B      BNE $EC5E
EC53   AD 18 D0   LDA $D018
EC56   29 FD      AND #$FD
EC58   8D 18 D0   STA $D018
EC5B   4C A8 E6   JMP $E6A8

; shift + commodore key check

EC5E   C9 08      CMP #$08
EC60   D0 07      BNE $EC69
EC62   A9 80      LDA #$80
EC64   0D 91 02   ORA $0291
EC67   30 09      BMI $EC72
EC69   C9 09      CMP #$09
EC6B   D0 EE      BNE $EC5B
EC6D   A9 7F      LDA #$7F
EC6F   2D 91 02   AND $0291
EC72   8D 91 02   STA $0291
EC75   4C A8 E6   JMP $E6A8

; control keyboard table

EC78   .BY $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF
EC80   .BY $1C,$17,$01,$9F,$1A,$13,$05,$FF
EC88   .BY $9C,$12,$04,$1E,$03,$06,$14,$18
EC90   .BY $1F,$19,$07,$9E,$02,$08,$15,$16
EC98   .BY $12,$09,$0A,$92,$0D,$0B,$0F,$0E
ECA0   .BY $FF,$10,$0C,$FF,$FF,$1B,$00,$FF
ECA8   .BY $1C,$FF,$1D,$FF,$FF,$1F,$1E,$FF
ECB0   .BY $90,$06,$FF,$05,$FF,$FF,$11,$FF
ECB8   .BY $FF

; default values for VIC chip

ECB9   .BY $00,$00              ; sprite 1 x,y
ECBB   .BY $00,$00              ; sprite 2 x,y
ECBD   .BY $00,$00              ; sprite 3 x,y
ECBF   .BY $00,$00              ; sprite 4 x,y
ECC1   .BY $00,$00              ; sprite 5 x,y
ECC3   .BY $00,$00              ; sprite 6 x,y
ECC5   .BY $00,$00              ; sprite 7 x,y
ECC7   .BY $00,$00              ; sprite 8 x,y
ECC9   .BY $00
ECCA   .BY $9B
ECCB   .BY $37
ECCC   .BY $00
ECCD   .BY $00
ECCE   .BY $00
ECCF   .BY $08
ECD0   .BY $00                  ; sprite Y expand
ECD1   .BY $14
ECD2   .BY $0F
ECD3   .BY $00
ECD4   .BY $00
ECD5   .BY $00                  ; sprite multi-color
ECD6   .BY $00                  ; sprite X expand
ECD7   .BY $00
ECD8   .BY $00
ECD9   .BY $0E                  ; boarder color
ECDA   .BY $06                  ; background color
ECDB   .BY $01
ECDC   .BY $02
ECDD   .BY $03
ECDE   .BY $04
ECDF   .BY $00                  ; sprite color
ECE0   .BY $01                  ; sprite color
ECE1   .BY $02                  ; sprite color
ECE2   .BY $03                  ; sprite color
ECE3   .BY $04                  ; sprite color
ECE4   .BY $05                  ; sprite color
ECE5   .BY $06                  ; sprite color
ECE6   .BY $07                  ; sprite color

; load

ECE7   .BY $4C,$4F,$41,$44,$0D

; run

ECEC   .BY $52,$55,$4E,$0D

; low bytes of screen line addresses

ECF0   .BY $00,$28,$50,$78,$A0
ECF5   .BY $C8,$F0,$18,$40,$68
ECFA   .BY $90,$B8,$E0,$08,$30
ECFF   .BY $58,$80,$A8,$D0,$F8
ED04   .BY $20,$48,$70,$98,$C0

; send talk on serial bus

ED09   09 40      ORA #$40
ED0B   .BY $2C

; send listen on serial bus

ED0C   09 20      ORA #$20
ED0E   20 A4 F0   JSR $F0A4
ED11   48         PHA
ED12   24 94      BIT $94
ED14   10 0A      BPL $ED20
ED16   38         SEC
ED17   66 A3      ROR $A3
ED19   20 40 ED   JSR $ED40
ED1C   46 94      LSR $94
ED1E   46 A3      LSR $A3
ED20   68         PLA
ED21   85 95      STA $95
ED23   78         SEI
ED24   20 97 EE   JSR $EE97
ED27   C9 3F      CMP #$3F
ED29   D0 03      BNE $ED2E
ED2B   20 85 EE   JSR $EE85
ED2E   AD 00 DD   LDA $DD00
ED31   09 08      ORA #$08
ED33   8D 00 DD   STA $DD00
ED36   78         SEI
ED37   20 8E EE   JSR $EE8E
ED3A   20 97 EE   JSR $EE97
ED3D   20 B3 EE   JSR $EEB3

; send byte from $95 on serial bus

ED40   78         SEI
ED41   20 97 EE   JSR $EE97
ED44   20 A9 EE   JSR $EEA9
ED47   B0 64      BCS $EDAD
ED49   20 85 EE   JSR $EE85
ED4C   24 A3      BIT $A3
ED4E   10 0A      BPL $ED5A
ED50   20 A9 EE   JSR $EEA9
ED53   90 FB      BCC $ED50
ED55   20 A9 EE   JSR $EEA9
ED58   B0 FB      BCS $ED55
ED5A   20 A9 EE   JSR $EEA9
ED5D   90 FB      BCC $ED5A
ED5F   20 8E EE   JSR $EE8E
ED62   A9 08      LDA #$08
ED64   85 A5      STA $A5
ED66   AD 00 DD   LDA $DD00
ED69   CD 00 DD   CMP $DD00
ED6C   D0 F8      BNE $ED66
ED6E   0A         ASL
ED6F   90 3F      BCC $EDB0
ED71   66 95      ROR $95
ED73   B0 05      BCS $ED7A
ED75   20 A0 EE   JSR $EEA0
ED78   D0 03      BNE $ED7D
ED7A   20 97 EE   JSR $EE97
ED7D   20 85 EE   JSR $EE85
ED80   EA         NOP
ED81   EA         NOP
ED82   EA         NOP
ED83   EA         NOP
ED84   AD 00 DD   LDA $DD00
ED87   29 DF      AND #$DF
ED89   09 10      ORA #$10
ED8B   8D 00 DD   STA $DD00
ED8E   C6 A5      DEC $A5
ED90   D0 D4      BNE $ED66
ED92   A9 04      LDA #$04
ED94   8D 07 DC   STA $DC07
ED97   A9 19      LDA #$19
ED99   8D 0F DC   STA $DC0F
ED9C   AD 0D DC   LDA $DC0D
ED9F   AD 0D DC   LDA $DC0D
EDA2   29 02      AND #$02
EDA4   D0 0A      BNE $EDB0
EDA6   20 A9 EE   JSR $EEA9
EDA9   B0 F4      BCS $ED9F
EDAB   58         CLI
EDAC   60         RTS
EDAD   A9 80      LDA #$80
EDAF   .BY $2C
EDB0   A9 03      LDA #$03
EDB2   20 1C FE   JSR $FE1C
EDB5   58         CLI
EDB6   18         CLC
EDB7   90 4A      BCC $EE03

; send secondary address (listen) on serial bus

EDB9   85 95      STA $95
EDBB   20 36 ED   JSR $ED36
EDBE   AD 00 DD   LDA $DD00
EDC1   29 F7      AND #$F7
EDC3   8D 00 DD   STA $DD00
EDC6   60         RTS

; send secondary address (talk) on serial bus

EDC7   85 95      STA $95
EDC9   20 36 ED   JSR $ED36
EDCC   78         SEI
EDCD   20 A0 EE   JSR $EEA0
EDD0   20 BE ED   JSR $EDBE
EDD3   20 85 EE   JSR $EE85
EDD6   20 A9 EE   JSR $EEA9
EDD9   30 FB      BMI $EDD6
EDDB   58         CLI
EDDC   60         RTS

; output byte on serial bus

EDDD   24 94      BIT $94
EDDF   30 05      BMI $EDE6
EDE1   38         SEC
EDE2   66 94      ROR $94
EDE4   D0 05      BNE $EDEB
EDE6   48         PHA
EDE7   20 40 ED   JSR $ED40
EDEA   68         PLA
EDEB   85 95      STA $95
EDED   18         CLC
EDEE   60         RTS

; send talk on serial bus

EDEF   78         SEI
EDF0   20 8E EE   JSR $EE8E
EDF3   AD 00 DD   LDA $DD00
EDF6   09 08      ORA #$08
EDF8   8D 00 DD   STA $DD00
EDFB   A9 5F      LDA #$5F
EDFD   .BY $2C

; send unlisten on serial bus

EDFE   A9 3F      LDA #$3F
EE00   20 11 ED   JSR $ED11
EE03   20 BE ED   JSR $EDBE
EE06   8A         TXA
EE07   A2 0A      LDX #$0A
EE09   CA         DEX
EE0A   D0 FD      BNE $EE09
EE0C   AA         TAX
EE0D   20 85 EE   JSR $EE85
EE10   4C 97 EE   JMP $EE97

; input byte on serial bus

EE13   78         SEI
EE14   A9 00      LDA #$00
EE16   85 A5      STA $A5
EE18   20 85 EE   JSR $EE85
EE1B   20 A9 EE   JSR $EEA9
EE1E   10 FB      BPL $EE1B
EE20   A9 01      LDA #$01
EE22   8D 07 DC   STA $DC07
EE25   A9 19      LDA #$19
EE27   8D 0F DC   STA $DC0F
EE2A   20 97 EE   JSR $EE97
EE2D   AD 0D DC   LDA $DC0D
EE30   AD 0D DC   LDA $DC0D
EE33   29 02      AND #$02
EE35   D0 07      BNE $EE3E
EE37   20 A9 EE   JSR $EEA9
EE3A   30 F4      BMI $EE30
EE3C   10 18      BPL $EE56
EE3E   A5 A5      LDA $A5
EE40   F0 05      BEQ $EE47
EE42   A9 02      LDA #$02
EE44   4C B2 ED   JMP $EDB2
EE47   20 A0 EE   JSR $EEA0
EE4A   20 85 EE   JSR $EE85
EE4D   A9 40      LDA #$40
EE4F   20 1C FE   JSR $FE1C
EE52   E6 A5      INC $A5
EE54   D0 CA      BNE $EE20
EE56   A9 08      LDA #$08
EE58   85 A5      STA $A5
EE5A   AD 00 DD   LDA $DD00
EE5D   CD 00 DD   CMP $DD00
EE60   D0 F8      BNE $EE5A
EE62   0A         ASL
EE63   10 F5      BPL $EE5A
EE65   66 A4      ROR $A4
EE67   AD 00 DD   LDA $DD00
EE6A   CD 00 DD   CMP $DD00
EE6D   D0 F8      BNE $EE67
EE6F   0A         ASL
EE70   30 F5      BMI $EE67
EE72   C6 A5      DEC $A5
EE74   D0 E4      BNE $EE5A
EE76   20 A0 EE   JSR $EEA0
EE79   24 90      BIT $90
EE7B   50 03      BVC $EE80
EE7D   20 06 EE   JSR $EE06
EE80   A5 A4      LDA $A4
EE82   58         CLI
EE83   18         CLC
EE84   60         RTS

; set serial clock line low

EE85   AD 00 DD   LDA $DD00
EE88   29 EF      AND #$EF
EE8A   8D 00 DD   STA $DD00
EE8D   60         RTS

; set serial clock line high

EE8E   AD 00 DD   LDA $DD00
EE91   09 10      ORA #$10
EE93   8D 00 DD   STA $DD00
EE96   60         RTS

; set serial data line low

EE97   AD 00 DD   LDA $DD00
EE9A   29 DF      AND #$DF
EE9C   8D 00 DD   STA $DD00
EE9F   60         RTS

; set serial data line high

EEA0   AD 00 DD   LDA $DD00
EEA3   09 20      ORA #$20
EEA5   8D 00 DD   STA $DD00
EEA8   60         RTS
EEA9   AD 00 DD   LDA $DD00
EEAC   CD 00 DD   CMP $DD00
EEAF   D0 F8      BNE $EEA9
EEB1   0A         ASL
EEB2   60         RTS

; delay 1 millisecond

EEB3   8A         TXA
EEB4   A2 B8      LDX #$B8
EEB6   CA         DEX
EEB7   D0 FD      BNE $EEB6
EEB9   AA         TAX
EEBA   60         RTS

; set next bit to transmit on RS-232

EEBB   A5 B4      LDA $B4
EEBD   F0 47      BEQ $EF06
EEBF   30 3F      BMI $EF00
EEC1   46 B6      LSR $B6
EEC3   A2 00      LDX #$00
EEC5   90 01      BCC $EEC8
EEC7   CA         DEX
EEC8   8A         TXA
EEC9   45 BD      EOR $BD
EECB   85 BD      STA $BD
EECD   C6 B4      DEC $B4
EECF   F0 06      BEQ $EED7
EED1   8A         TXA
EED2   29 04      AND #$04
EED4   85 B5      STA $B5
EED6   60         RTS
EED7   A9 20      LDA #$20
EED9   2C 94 02   BIT $0294
EEDC   F0 14      BEQ $EEF2
EEDE   30 1C      BMI $EEFC
EEE0   70 14      BVS $EEF6
EEE2   A5 BD      LDA $BD
EEE4   D0 01      BNE $EEE7
EEE6   CA         DEX
EEE7   C6 B4      DEC $B4
EEE9   AD 93 02   LDA $0293
EEEC   10 E3      BPL $EED1
EEEE   C6 B4      DEC $B4
EEF0   D0 DF      BNE $EED1
EEF2   E6 B4      INC $B4
EEF4   D0 F0      BNE $EEE6
EEF6   A5 BD      LDA $BD
EEF8   F0 ED      BEQ $EEE7
EEFA   D0 EA      BNE $EEE6
EEFC   70 E9      BVS $EEE7
EEFE   50 E6      BVC $EEE6
EF00   E6 B4      INC $B4
EF02   A2 FF      LDX #$FF
EF04   D0 CB      BNE $EED1
EF06   AD 94 02   LDA $0294
EF09   4A         LSR
EF0A   90 07      BCC $EF13
EF0C   2C 01 DD   BIT $DD01
EF0F   10 1D      BPL $EF2E
EF11   50 1E      BVC $EF31
EF13   A9 00      LDA #$00
EF15   85 BD      STA $BD
EF17   85 B5      STA $B5
EF19   AE 98 02   LDX $0298
EF1C   86 B4      STX $B4
EF1E   AC 9D 02   LDY $029D
EF21   CC 9E 02   CPY $029E
EF24   F0 13      BEQ $EF39
EF26   B1 F9      LDA ($F9),Y
EF28   85 B6      STA $B6
EF2A   EE 9D 02   INC $029D
EF2D   60         RTS

; handle RS-232 errors

EF2E   A9 40      LDA #$40
EF30   .BY $2C
EF31   A9 10      LDA #$10
EF33   0D 97 02   ORA $0297
EF36   8D 97 02   STA $0297
EF39   A9 01      LDA #$01
EF3B   8D 0D DD   STA $DD0D
EF3E   4D A1 02   EOR $02A1
EF41   09 80      ORA #$80
EF43   8D A1 02   STA $02A1
EF46   8D 0D DD   STA $DD0D
EF49   60         RTS

; check control register

EF4A   A2 09      LDX #$09
EF4C   A9 20      LDA #$20
EF4E   2C 93 02   BIT $0293
EF51   F0 01      BEQ $EF54
EF53   CA         DEX
EF54   50 02      BVC $EF58
EF56   CA         DEX
EF57   CA         DEX
EF58   60         RTS

; add bit input on RS-232 bus to word being input

EF59   A6 A9      LDX $A9
EF5B   D0 33      BNE $EF90
EF5D   C6 A8      DEC $A8
EF5F   F0 36      BEQ $EF97
EF61   30 0D      BMI $EF70
EF63   A5 A7      LDA $A7
EF65   45 AB      EOR $AB
EF67   85 AB      STA $AB
EF69   46 A7      LSR $A7
EF6B   66 AA      ROR $AA
EF6D   60         RTS

; handle end of word for RS-232 input

EF6E   C6 A8      DEC $A8
EF70   A5 A7      LDA $A7
EF72   F0 67      BEQ $EFDB
EF74   AD 93 02   LDA $0293
EF77   0A         ASL
EF78   A9 01      LDA #$01
EF7A   65 A8      ADC $A8
EF7C   D0 EF      BNE $EF6D

; enable byte reception

EF7E   A9 90      LDA #$90
EF80   8D 0D DD   STA $DD0D
EF83   0D A1 02   ORA $02A1
EF86   8D A1 02   STA $02A1
EF89   85 A9      STA $A9
EF8B   A9 02      LDA #$02
EF8D   4C 3B EF   JMP $EF3B

; receiver start bit test

EF90   A5 A7      LDA $A7
EF92   D0 EA      BNE $EF7E
EF94   4C D3 E4   JMP $E4D3

; put received data into RS-232 buffer

EF97   AC 9B 02   LDY $029B
EF9A   C8         INY
EF9B   CC 9C 02   CPY $029C
EF9E   F0 2A      BEQ $EFCA
EFA0   8C 9B 02   STY $029B
EFA3   88         DEY
EFA4   A5 AA      LDA $AA
EFA6   AE 98 02   LDX $0298
EFA9   E0 09      CPX #$09
EFAB   F0 04      BEQ $EFB1
EFAD   4A         LSR
EFAE   E8         INX
EFAF   D0 F8      BNE $EFA9
EFB1   91 F7      STA ($F7),Y
EFB3   A9 20      LDA #$20
EFB5   2C 94 02   BIT $0294
EFB8   F0 B4      BEQ $EF6E
EFBA   30 B1      BMI $EF6D
EFBC   A5 A7      LDA $A7
EFBE   45 AB      EOR $AB
EFC0   F0 03      BEQ $EFC5
EFC2   70 A9      BVS $EF6D
EFC4   .BY $2C
EFC5   50 A6      BVC $EF6D
EFC7   A9 01      LDA #$01
EFC9   .BY $2C
EFCA   A9 04      LDA #$04
EFCC   .BY $2C
EFCD   A9 80      LDA #$80
EFCF   .BY $2C
EFD0   A9 02      LDA #$02
EFD2   0D 97 02   ORA $0297
EFD5   8D 97 02   STA $0297
EFD8   4C 7E EF   JMP $EF7E
EFDB   A5 AA      LDA $AA
EFDD   D0 F1      BNE $EFD0
EFDF   F0 EC      BEQ $EFCD

; output of RS-232 device

EFE1   85 9A      STA $9A
EFE3   AD 94 02   LDA $0294
EFE6   4A         LSR
EFE7   90 29      BCC $F012
EFE9   A9 02      LDA #$02
EFEB   2C 01 DD   BIT $DD01
EFEE   10 1D      BPL $F00D
EFF0   D0 20      BNE $F012
EFF2   AD A1 02   LDA $02A1
EFF5   29 02      AND #$02
EFF7   D0 F9      BNE $EFF2
EFF9   2C 01 DD   BIT $DD01
EFFC   70 FB      BVS $EFF9
EFFE   AD 01 DD   LDA $DD01
F001   09 02      ORA #$02
F003   8D 01 DD   STA $DD01
F006   2C 01 DD   BIT $DD01
F009   70 07      BVS $F012
F00B   30 F9      BMI $F006
F00D   A9 40      LDA #$40
F00F   8D 97 02   STA $0297
F012   18         CLC
F013   60         RTS

; buffer char to output on RS-232

F014   20 28 F0   JSR $F028
F017   AC 9E 02   LDY $029E
F01A   C8         INY
F01B   CC 9D 02   CPY $029D
F01E   F0 F4      BEQ $F014
F020   8C 9E 02   STY $029E
F023   88         DEY
F024   A5 9E      LDA $9E
F026   91 F9      STA ($F9),Y
F028   AD A1 02   LDA $02A1
F02B   4A         LSR
F02C   B0 1E      BCS $F04C
F02E   A9 10      LDA #$10
F030   8D 0E DD   STA $DD0E
F033   AD 99 02   LDA $0299
F036   8D 04 DD   STA $DD04
F039   AD 9A 02   LDA $029A
F03C   8D 05 DD   STA $DD05
F03F   A9 81      LDA #$81
F041   20 3B EF   JSR $EF3B
F044   20 06 EF   JSR $EF06
F047   A9 11      LDA #$11
F049   8D 0E DD   STA $DD0E
F04C   60         RTS

; initalise RS-232 input

F04D   85 99      STA $99
F04F   AD 94 02   LDA $0294
F052   4A         LSR
F053   90 28      BCC $F07D
F055   29 08      AND #$08
F057   F0 24      BEQ $F07D
F059   A9 02      LDA #$02
F05B   2C 01 DD   BIT $DD01
F05E   10 AD      BPL $F00D
F060   F0 22      BEQ $F084
F062   AD A1 02   LDA $02A1
F065   4A         LSR
F066   B0 FA      BCS $F062
F068   AD 01 DD   LDA $DD01
F06B   29 FD      AND #$FD
F06D   8D 01 DD   STA $DD01
F070   AD 01 DD   LDA $DD01
F073   29 04      AND #$04
F075   F0 F9      BEQ $F070
F077   A9 90      LDA #$90
F079   18         CLC
F07A   4C 3B EF   JMP $EF3B
F07D   AD A1 02   LDA $02A1
F080   29 12      AND #$12
F082   F0 F3      BEQ $F077
F084   18         CLC
F085   60         RTS

; get next character from RS-232 input buffer

F086   AD 97 02   LDA $0297
F089   AC 9C 02   LDY $029C
F08C   CC 9B 02   CPY $029B
F08F   F0 0B      BEQ $F09C
F091   29 F7      AND #$F7
F093   8D 97 02   STA $0297
F096   B1 F7      LDA ($F7),Y
F098   EE 9C 02   INC $029C
F09B   60         RTS
F09C   09 08      ORA #$08
F09E   8D 97 02   STA $0297
F0A1   A9 00      LDA #$00
F0A3   60         RTS

; protect serial/casette routine from RS-232 NMI's

F0A4   48         PHA
F0A5   AD A1 02   LDA $02A1
F0A8   F0 11      BEQ $F0BB
F0AA   AD A1 02   LDA $02A1
F0AD   29 03      AND #$03
F0AF   D0 F9      BNE $F0AA
F0B1   A9 10      LDA #$10
F0B3   8D 0D DD   STA $DD0D
F0B6   A9 00      LDA #$00
F0B8   8D A1 02   STA $02A1
F0BB   68         PLA
F0BC   60         RTS

; kernal I/O messages

F0BD   .BY $0D                  ; I/O error
F0BE   .BY $49,$2F,$4F
F0C1   .BY $20,$45,$52,$52,$4F,$52
F0C7   .BY $20,$A3

F0C9   .BY $0D                  ; searching for
F0CA   .BY $53,$45,$41,$52,$43,
F0CF   .BY $48,$49,$4E,$47,$A0
F0D4   .BY $46,$4F,$52,$A0

F0D8   .BY $0D                  ; press play on tape
F0D9   .BY $50,$52,$45,$53,$53
F0DE   .BY $20,$50,$4C,$41,$59
F0E3   .BY $20,$4F,$4E
F0E6   .BY $20,$54,$41,$50,$C5

F0EB   .BY $50,$52,$45,$53,$53  ; press record and play on tape
F0F0   .BY $20,$52,$45,$43,
F0F4   .BY $4F,$52,$44
F0F7   .BY $20,$26
F0F9   .BY $20,$50,$4C,$41,$59
F0FE   .BY $20,$4F,$4E
F101   .BY $20,$54,$41,$50,$C5

F106   .BY $0D                  ; loading
F107   .BY $4C,$4F,$41,$44,
F10B   .BY $49,$4E,$C7

F10E   .BY $0D                  ; saving
F10F   .BY $53,$41,$56,$49,
F113   .BY $4E,$47,$A0

F116   .BY $0D                  ; verifying
F117   .BY $56,$45,$52,$49,$46,
F11C   .BY $59,$49,$4E,$C7

F120   .BY $0D                  ; found
F121   .BY $46,$4F,$55,$4E,$44,$A0

F127   .BY $0D                  ; ok
F128   .BY $4F,$4B,$8D

; print kernal message indexed by Y

F12B   24 9D      BIT $9D
F12D   10 0D      BPL $F13C
F12F   B9 BD F0   LDA $F0BD,Y
F132   08         PHP
F133   29 7F      AND #$7F
F135   20 D2 FF   JSR $FFD2
F138   C8         INY
F139   28         PLP
F13A   10 F3      BPL $F12F
F13C   18         CLC
F13D   60         RTS

; get a character

F13E   A5 99      LDA $99
F140   D0 08      BNE $F14A
F142   A5 C6      LDA $C6
F144   F0 0F      BEQ $F155
F146   78         SEI
F147   4C B4 E5   JMP $E5B4
F14A   C9 02      CMP #$02
F14C   D0 18      BNE $F166
F14E   84 97      STY $97
F150   20 86 F0   JSR $F086
F153   A4 97      LDY $97
F155   18         CLC
F156   60         RTS

; input a character

F157   A5 99      LDA $99
F159   D0 0B      BNE $F166
F15B   A5 D3      LDA $D3
F15D   85 CA      STA $CA
F15F   A5 D6      LDA $D6
F161   85 C9      STA $C9
F163   4C 32 E6   JMP $E632
F166   C9 03      CMP #$03
F168   D0 09      BNE $F173
F16A   85 D0      STA $D0
F16C   A5 D5      LDA $D5
F16E   85 C8      STA $C8
F170   4C 32 E6   JMP $E632
F173   B0 38      BCS $F1AD
F175   C9 02      CMP #$02
F177   F0 3F      BEQ $F1B8
F179   86 97      STX $97
F17B   20 99 F1   JSR $F199
F17E   B0 16      BCS $F196
F180   48         PHA
F181   20 99 F1   JSR $F199
F184   B0 0D      BCS $F193
F186   D0 05      BNE $F18D
F188   A9 40      LDA #$40
F18A   20 1C FE   JSR $FE1C
F18D   C6 A6      DEC $A6
F18F   A6 97      LDX $97
F191   68         PLA
F192   60         RTS
F193   AA         TAX
F194   68         PLA
F195   8A         TXA
F196   A6 97      LDX $97
F198   60         RTS

; read a byte from cassette buffer

F199   20 0D F8   JSR $F80D
F19C   D0 0B      BNE $F1A9
F19E   20 41 F8   JSR $F841
F1A1   B0 11      BCS $F1B4
F1A3   A9 00      LDA #$00
F1A5   85 A6      STA $A6
F1A7   F0 F0      BEQ $F199
F1A9   B1 B2      LDA ($B2),Y
F1AB   18         CLC
F1AC   60         RTS
F1AD   A5 90      LDA $90
F1AF   F0 04      BEQ $F1B5
F1B1   A9 0D      LDA #$0D
F1B3   18         CLC
F1B4   60         RTS

; read a byte from serial bus

F1B5   4C 13 EE   JMP $EE13

; read a byte from RS-232 bus

F1B8   20 4E F1   JSR $F14E
F1BB   B0 F7      BCS $F1B4
F1BD   C9 00      CMP #$00
F1BF   D0 F2      BNE $F1B3
F1C1   AD 97 02   LDA $0297
F1C4   29 60      AND #$60
F1C6   D0 E9      BNE $F1B1
F1C8   F0 EE      BEQ $F1B8

; output a character

F1CA   48         PHA
F1CB   A5 9A      LDA $9A
F1CD   C9 03      CMP #$03
F1CF   D0 04      BNE $F1D5
F1D1   68         PLA
F1D2   4C 16 E7   JMP $E716
F1D5   90 04      BCC $F1DB
F1D7   68         PLA
F1D8   4C DD ED   JMP $EDDD
F1DB   4A         LSR
F1DC   68         PLA
F1DD   85 9E      STA $9E
F1DF   8A         TXA
F1E0   48         PHA
F1E1   98         TYA
F1E2   48         PHA
F1E3   90 23      BCC $F208
F1E5   20 0D F8   JSR $F80D
F1E8   D0 0E      BNE $F1F8
F1EA   20 64 F8   JSR $F864
F1ED   B0 0E      BCS $F1FD
F1EF   A9 02      LDA #$02
F1F1   A0 00      LDY #$00
F1F3   91 B2      STA ($B2),Y
F1F5   C8         INY
F1F6   84 A6      STY $A6
F1F8   A5 9E      LDA $9E
F1FA   91 B2      STA ($B2),Y
F1FC   18         CLC
F1FD   68         PLA
F1FE   A8         TAY
F1FF   68         PLA
F200   AA         TAX
F201   A5 9E      LDA $9E
F203   90 02      BCC $F207
F205   A9 00      LDA #$00
F207   60         RTS
F208   20 17 F0   JSR $F017
F20B   4C FC F1   JMP $F1FC

; set input device

F20E   20 0F F3   JSR $F30F
F211   F0 03      BEQ $F216
F213   4C 01 F7   JMP $F701
F216   20 1F F3   JSR $F31F
F219   A5 BA      LDA $BA
F21B   F0 16      BEQ $F233
F21D   C9 03      CMP #$03
F21F   F0 12      BEQ $F233
F221   B0 14      BCS $F237
F223   C9 02      CMP #$02
F225   D0 03      BNE $F22A
F227   4C 4D F0   JMP $F04D
F22A   A6 B9      LDX $B9
F22C   E0 60      CPX #$60
F22E   F0 03      BEQ $F233
F230   4C 0A F7   JMP $F70A
F233   85 99      STA $99
F235   18         CLC
F236   60         RTS

; set serial bus input device

F237   AA         TAX
F238   20 09 ED   JSR $ED09
F23B   A5 B9      LDA $B9
F23D   10 06      BPL $F245
F23F   20 CC ED   JSR $EDCC
F242   4C 48 F2   JMP $F248
F245   20 C7 ED   JSR $EDC7
F248   8A         TXA
F249   24 90      BIT $90
F24B   10 E6      BPL $F233
F24D   4C 07 F7   JMP $F707

; set output device

F250   20 0F F3   JSR $F30F
F253   F0 03      BEQ $F258
F255   4C 01 F7   JMP $F701
F258   20 1F F3   JSR $F31F
F25B   A5 BA      LDA $BA
F25D   D0 03      BNE $F262
F25F   4C 0D F7   JMP $F70D
F262   C9 03      CMP #$03
F264   F0 0F      BEQ $F275
F266   B0 11      BCS $F279
F268   C9 02      CMP #$02
F26A   D0 03      BNE $F26F
F26C   4C E1 EF   JMP $EFE1
F26F   A6 B9      LDX $B9
F271   E0 60      CPX #$60
F273   F0 EA      BEQ $F25F
F275   85 9A      STA $9A
F277   18         CLC
F278   60         RTS

; set serial bus output device

F279   AA         TAX
F27A   20 0C ED   JSR $ED0C
F27D   A5 B9      LDA $B9
F27F   10 05      BPL $F286
F281   20 BE ED   JSR $EDBE
F284   D0 03      BNE $F289
F286   20 B9 ED   JSR $EDB9
F289   8A         TXA
F28A   24 90      BIT $90
F28C   10 E7      BPL $F275
F28E   4C 07 F7   JMP $F707

; close a file

F291   20 14 F3   JSR $F314
F294   F0 02      BEQ $F298
F296   18         CLC
F297   60         RTS
F298   20 1F F3   JSR $F31F
F29B   8A         TXA
F29C   48         PHA
F29D   A5 BA      LDA $BA
F29F   F0 50      BEQ $F2F1
F2A1   C9 03      CMP #$03
F2A3   F0 4C      BEQ $F2F1
F2A5   B0 47      BCS $F2EE
F2A7   C9 02      CMP #$02
F2A9   D0 1D      BNE $F2C8
F2AB   68         PLA
F2AC   20 F2 F2   JSR $F2F2
F2AF   20 83 F4   JSR $F483
F2B2   20 27 FE   JSR $FE27
F2B5   A5 F8      LDA $F8
F2B7   F0 01      BEQ $F2BA
F2B9   C8         INY
F2BA   A5 FA      LDA $FA
F2BC   F0 01      BEQ $F2BF
F2BE   C8         INY
F2BF   A9 00      LDA #$00
F2C1   85 F8      STA $F8
F2C3   85 FA      STA $FA
F2C5   4C 7D F4   JMP $F47D

; close cassette device

F2C8   A5 B9      LDA $B9
F2CA   29 0F      AND #$0F
F2CC   F0 23      BEQ $F2F1
F2CE   20 D0 F7   JSR $F7D0
F2D1   A9 00      LDA #$00
F2D3   38         SEC
F2D4   20 DD F1   JSR $F1DD
F2D7   20 64 F8   JSR $F864
F2DA   90 04      BCC $F2E0
F2DC   68         PLA
F2DD   A9 00      LDA #$00
F2DF   60         RTS
F2E0   A5 B9      LDA $B9
F2E2   C9 62      CMP #$62
F2E4   D0 0B      BNE $F2F1
F2E6   A9 05      LDA #$05
F2E8   20 6A F7   JSR $F76A
F2EB   4C F1 F2   JMP $F2F1

; close serial bus device

F2EE   20 42 F6   JSR $F642
F2F1   68         PLA

; reorganise file tables

F2F2   AA         TAX
F2F3   C6 98      DEC $98
F2F5   E4 98      CPX $98
F2F7   F0 14      BEQ $F30D
F2F9   A4 98      LDY $98
F2FB   B9 59 02   LDA $0259,Y
F2FE   9D 59 02   STA $0259,X
F301   B9 63 02   LDA $0263,Y
F304   9D 63 02   STA $0263,X
F307   B9 6D 02   LDA $026D,Y
F30A   9D 6D 02   STA $026D,X
F30D   18         CLC
F30E   60         RTS

; check X against logical file table

F30F   A9 00      LDA #$00
F311   85 90      STA $90
F313   8A         TXA
F314   A6 98      LDX $98
F316   CA         DEX
F317   30 15      BMI $F32E
F319   DD 59 02   CMP $0259,X
F31C   D0 F8      BNE $F316
F31E   60         RTS

; set file parameters depending on X

F31F   BD 59 02   LDA $0259,X
F322   85 B8      STA $B8
F324   BD 63 02   LDA $0263,X
F327   85 BA      STA $BA
F329   BD 6D 02   LDA $026D,X
F32C   85 B9      STA $B9
F32E   60         RTS

; close all files

F32F   A9 00      LDA #$00
F331   85 98      STA $98

; restore I/O to default devices

F333   A2 03      LDX #$03
F335   E4 9A      CPX $9A
F337   B0 03      BCS $F33C
F339   20 FE ED   JSR $EDFE
F33C   E4 99      CPX $99
F33E   B0 03      BCS $F343
F340   20 EF ED   JSR $EDEF
F343   86 9A      STX $9A
F345   A9 00      LDA #$00
F347   85 99      STA $99
F349   60         RTS

; open a file

F34A   A6 B8      LDX $B8
F34C   D0 03      BNE $F351
F34E   4C 0A F7   JMP $F70A
F351   20 0F F3   JSR $F30F
F354   D0 03      BNE $F359
F356   4C FE F6   JMP $F6FE
F359   A6 98      LDX $98
F35B   E0 0A      CPX #$0A
F35D   90 03      BCC $F362
F35F   4C FB F6   JMP $F6FB
F362   E6 98      INC $98
F364   A5 B8      LDA $B8
F366   9D 59 02   STA $0259,X
F369   A5 B9      LDA $B9
F36B   09 60      ORA #$60
F36D   85 B9      STA $B9
F36F   9D 6D 02   STA $026D,X
F372   A5 BA      LDA $BA
F374   9D 63 02   STA $0263,X
F377   F0 5A      BEQ $F3D3
F379   C9 03      CMP #$03
F37B   F0 56      BEQ $F3D3
F37D   90 05      BCC $F384
F37F   20 D5 F3   JSR $F3D5
F382   90 4F      BCC $F3D3
F384   C9 02      CMP #$02
F386   D0 03      BNE $F38B
F388   4C 09 F4   JMP $F409

; open for cassette device

F38B   20 D0 F7   JSR $F7D0
F38E   B0 03      BCS $F393
F390   4C 13 F7   JMP $F713
F393   A5 B9      LDA $B9
F395   29 0F      AND #$0F
F397   D0 1F      BNE $F3B8
F399   20 17 F8   JSR $F817
F39C   B0 36      BCS $F3D4
F39E   20 AF F5   JSR $F5AF
F3A1   A5 B7      LDA $B7
F3A3   F0 0A      BEQ $F3AF
F3A5   20 EA F7   JSR $F7EA
F3A8   90 18      BCC $F3C2
F3AA   F0 28      BEQ $F3D4
F3AC   4C 04 F7   JMP $F704
F3AF   20 2C F7   JSR $F72C
F3B2   F0 20      BEQ $F3D4
F3B4   90 0C      BCC $F3C2
F3B6   B0 F4      BCS $F3AC

; open cassette for input

F3B8   20 38 F8   JSR $F838
F3BB   B0 17      BCS $F3D4
F3BD   A9 04      LDA #$04
F3BF   20 6A F7   JSR $F76A
F3C2   A9 BF      LDA #$BF
F3C4   A4 B9      LDY $B9
F3C6   C0 60      CPY #$60
F3C8   F0 07      BEQ $F3D1
F3CA   A0 00      LDY #$00
F3CC   A9 02      LDA #$02
F3CE   91 B2      STA ($B2),Y
F3D0   98         TYA
F3D1   85 A6      STA $A6
F3D3   18         CLC
F3D4   60         RTS

; open for serial bus devices

F3D5   A5 B9      LDA $B9
F3D7   30 FA      BMI $F3D3
F3D9   A4 B7      LDY $B7
F3DB   F0 F6      BEQ $F3D3
F3DD   A9 00      LDA #$00
F3DF   85 90      STA $90
F3E1   A5 BA      LDA $BA
F3E3   20 0C ED   JSR $ED0C
F3E6   A5 B9      LDA $B9
F3E8   09 F0      ORA #$F0
F3EA   20 B9 ED   JSR $EDB9
F3ED   A5 90      LDA $90
F3EF   10 05      BPL $F3F6
F3F1   68         PLA
F3F2   68         PLA
F3F3   4C 07 F7   JMP $F707
F3F6   A5 B7      LDA $B7
F3F8   F0 0C      BEQ $F406
F3FA   A0 00      LDY #$00
F3FC   B1 BB      LDA ($BB),Y
F3FE   20 DD ED   JSR $EDDD
F401   C8         INY
F402   C4 B7      CPY $B7
F404   D0 F6      BNE $F3FC
F406   4C 54 F6   JMP $F654

; open RS-232 device

F409   20 83 F4   JSR $F483
F40C   8C 97 02   STY $0297
F40F   C4 B7      CPY $B7
F411   F0 0A      BEQ $F41D
F413   B1 BB      LDA ($BB),Y
F415   99 93 02   STA $0293,Y
F418   C8         INY
F419   C0 04      CPY #$04
F41B   D0 F2      BNE $F40F
F41D   20 4A EF   JSR $EF4A
F420   8E 98 02   STX $0298
F423   AD 93 02   LDA $0293
F426   29 0F      AND #$0F
F428   F0 1C      BEQ $F446
F42A   0A         ASL
F42B   AA         TAX
F42C   AD A6 02   LDA $02A6
F42F   D0 09      BNE $F43A
F431   BC C1 FE   LDY $FEC1,X
F434   BD C0 FE   LDA $FEC0,X
F437   4C 40 F4   JMP $F440
F43A   BC EB E4   LDY $E4EB,X
F43D   BD EA E4   LDA $E4EA,X
F440   8C 96 02   STY $0296
F443   8D 95 02   STA $0295
F446   AD 95 02   LDA $0295
F449   0A         ASL
F44A   20 2E FF   JSR $FF2E
F44D   AD 94 02   LDA $0294
F450   4A         LSR
F451   90 09      BCC $F45C
F453   AD 01 DD   LDA $DD01
F456   0A         ASL
F457   B0 03      BCS $F45C
F459   20 0D F0   JSR $F00D
F45C   AD 9B 02   LDA $029B
F45F   8D 9C 02   STA $029C
F462   AD 9E 02   LDA $029E
F465   8D 9D 02   STA $029D
F468   20 27 FE   JSR $FE27
F46B   A5 F8      LDA $F8
F46D   D0 05      BNE $F474
F46F   88         DEY
F470   84 F8      STY $F8
F472   86 F7      STX $F7
F474   A5 FA      LDA $FA
F476   D0 05      BNE $F47D
F478   88         DEY
F479   84 FA      STY $FA
F47B   86 F9      STX $F9
F47D   38         SEC
F47E   A9 F0      LDA #$F0
F480   4C 2D FE   JMP $FE2D

; initialise CIA 2

F483   A9 7F      LDA #$7F
F485   8D 0D DD   STA $DD0D
F488   A9 06      LDA #$06
F48A   8D 03 DD   STA $DD03
F48D   8D 01 DD   STA $DD01
F490   A9 04      LDA #$04
F492   0D 00 DD   ORA $DD00
F495   8D 00 DD   STA $DD00
F498   A0 00      LDY #$00
F49A   8C A1 02   STY $02A1
F49D   60         RTS

; load ram from a device

F49E   86 C3      STX $C3
F4A0   84 C4      STY $C4
F4A2   6C 30 03   JMP ($0330)   ; normally F4A5

; standard load ram entry

F4A5   85 93      STA $93
F4A7   A9 00      LDA #$00
F4A9   85 90      STA $90
F4AB   A5 BA      LDA $BA
F4AD   D0 03      BNE $F4B2
F4AF   4C 13 F7   JMP $F713
F4B2   C9 03      CMP #$03
F4B4   F0 F9      BEQ $F4AF
F4B6   90 7B      BCC $F533
F4B8   A4 B7      LDY $B7
F4BA   D0 03      BNE $F4BF
F4BC   4C 10 F7   JMP $F710
F4BF   A6 B9      LDX $B9
F4C1   20 AF F5   JSR $F5AF
F4C4   A9 60      LDA #$60
F4C6   85 B9      STA $B9
F4C8   20 D5 F3   JSR $F3D5
F4CB   A5 BA      LDA $BA
F4CD   20 09 ED   JSR $ED09
F4D0   A5 B9      LDA $B9
F4D2   20 C7 ED   JSR $EDC7
F4D5   20 13 EE   JSR $EE13
F4D8   85 AE      STA $AE
F4DA   A5 90      LDA $90
F4DC   4A         LSR
F4DD   4A         LSR
F4DE   B0 50      BCS $F530
F4E0   20 13 EE   JSR $EE13
F4E3   85 AF      STA $AF
F4E5   8A         TXA
F4E6   D0 08      BNE $F4F0
F4E8   A5 C3      LDA $C3
F4EA   85 AE      STA $AE
F4EC   A5 C4      LDA $C4
F4EE   85 AF      STA $AF
F4F0   20 D2 F5   JSR $F5D2
F4F3   A9 FD      LDA #$FD
F4F5   25 90      AND $90
F4F7   85 90      STA $90
F4F9   20 E1 FF   JSR $FFE1
F4FC   D0 03      BNE $F501
F4FE   4C 33 F6   JMP $F633
F501   20 13 EE   JSR $EE13
F504   AA         TAX
F505   A5 90      LDA $90
F507   4A         LSR
F508   4A         LSR
F509   B0 E8      BCS $F4F3
F50B   8A         TXA
F50C   A4 93      LDY $93
F50E   F0 0C      BEQ $F51C
F510   A0 00      LDY #$00
F512   D1 AE      CMP ($AE),Y
F514   F0 08      BEQ $F51E
F516   A9 10      LDA #$10
F518   20 1C FE   JSR $FE1C
F51B   .BY $2C
F51C   91 AE      STA ($AE),Y
F51E   E6 AE      INC $AE
F520   D0 02      BNE $F524
F522   E6 AF      INC $AF
F524   24 90      BIT $90
F526   50 CB      BVC $F4F3
F528   20 EF ED   JSR $EDEF
F52B   20 42 F6   JSR $F642
F52E   90 79      BCC $F5A9
F530   4C 04 F7   JMP $F704
F533   4A         LSR
F534   B0 03      BCS $F539
F536   4C 13 F7   JMP $F713
F539   20 D0 F7   JSR $F7D0
F53C   B0 03      BCS $F541
F53E   4C 13 F7   JMP $F713
F541   20 17 F8   JSR $F817
F544   B0 68      BCS $F5AE
F546   20 AF F5   JSR $F5AF
F549   A5 B7      LDA $B7
F54B   F0 09      BEQ $F556
F54D   20 EA F7   JSR $F7EA
F550   90 0B      BCC $F55D
F552   F0 5A      BEQ $F5AE
F554   B0 DA      BCS $F530
F556   20 2C F7   JSR $F72C
F559   F0 53      BEQ $F5AE
F55B   B0 D3      BCS $F530
F55D   A5 90      LDA $90
F55F   29 10      AND #$10
F561   38         SEC
F562   D0 4A      BNE $F5AE
F564   E0 01      CPX #$01
F566   F0 11      BEQ $F579
F568   E0 03      CPX #$03
F56A   D0 DD      BNE $F549
F56C   A0 01      LDY #$01
F56E   B1 B2      LDA ($B2),Y
F570   85 C3      STA $C3
F572   C8         INY
F573   B1 B2      LDA ($B2),Y
F575   85 C4      STA $C4
F577   B0 04      BCS $F57D
F579   A5 B9      LDA $B9
F57B   D0 EF      BNE $F56C
F57D   A0 03      LDY #$03
F57F   B1 B2      LDA ($B2),Y
F581   A0 01      LDY #$01
F583   F1 B2      SBC ($B2),Y
F585   AA         TAX
F586   A0 04      LDY #$04
F588   B1 B2      LDA ($B2),Y
F58A   A0 02      LDY #$02
F58C   F1 B2      SBC ($B2),Y
F58E   A8         TAY
F58F   18         CLC
F590   8A         TXA
F591   65 C3      ADC $C3
F593   85 AE      STA $AE
F595   98         TYA
F596   65 C4      ADC $C4
F598   85 AF      STA $AF
F59A   A5 C3      LDA $C3
F59C   85 C1      STA $C1
F59E   A5 C4      LDA $C4
F5A0   85 C2      STA $C2
F5A2   20 D2 F5   JSR $F5D2
F5A5   20 4A F8   JSR $F84A
F5A8   .BY $24
F5A9   18         CLC
F5AA   A6 AE      LDX $AE
F5AC   A4 AF      LDY $AF
F5AE   60         RTS

; handle messages for loading

F5AF   A5 9D      LDA $9D
F5B1   10 1E      BPL $F5D1
F5B3   A0 0C      LDY #$0C
F5B5   20 2F F1   JSR $F12F
F5B8   A5 B7      LDA $B7
F5BA   F0 15      BEQ $F5D1
F5BC   A0 17      LDY #$17
F5BE   20 2F F1   JSR $F12F
F5C1   A4 B7      LDY $B7
F5C3   F0 0C      BEQ $F5D1
F5C5   A0 00      LDY #$00
F5C7   B1 BB      LDA ($BB),Y
F5C9   20 D2 FF   JSR $FFD2
F5CC   C8         INY
F5CD   C4 B7      CPY $B7
F5CF   D0 F6      BNE $F5C7
F5D1   60         RTS

; do load/verify message

F5D2   A0 49      LDY #$49
F5D4   A5 93      LDA $93
F5D6   F0 02      BEQ $F5DA
F5D8   A0 59      LDY #$59
F5DA   4C 2B F1   JMP $F12B

; save ram to a device

F5DD   86 AE      STX $AE
F5DF   84 AF      STY $AF
F5E1   AA         TAX
F5E2   B5 00      LDA $00,X
F5E4   85 C1      STA $C1
F5E6   B5 01      LDA $01,X
F5E8   85 C2      STA $C2
F5EA   6C 32 03   JMP ($0332)   ; normally F5ED

; standard save ram entry

F5ED   A5 BA      LDA $BA
F5EF   D0 03      BNE $F5F4
F5F1   4C 13 F7   JMP $F713
F5F4   C9 03      CMP #$03
F5F6   F0 F9      BEQ $F5F1
F5F8   90 5F      BCC $F659
F5FA   A9 61      LDA #$61
F5FC   85 B9      STA $B9
F5FE   A4 B7      LDY $B7
F600   D0 03      BNE $F605
F602   4C 10 F7   JMP $F710
F605   20 D5 F3   JSR $F3D5
F608   20 8F F6   JSR $F68F
F60B   A5 BA      LDA $BA
F60D   20 0C ED   JSR $ED0C
F610   A5 B9      LDA $B9
F612   20 B9 ED   JSR $EDB9
F615   A0 00      LDY #$00
F617   20 8E FB   JSR $FB8E
F61A   A5 AC      LDA $AC
F61C   20 DD ED   JSR $EDDD
F61F   A5 AD      LDA $AD
F621   20 DD ED   JSR $EDDD
F624   20 D1 FC   JSR $FCD1
F627   B0 16      BCS $F63F
F629   B1 AC      LDA ($AC),Y
F62B   20 DD ED   JSR $EDDD
F62E   20 E1 FF   JSR $FFE1
F631   D0 07      BNE $F63A
F633   20 42 F6   JSR $F642
F636   A9 00      LDA #$00
F638   38         SEC
F639   60         RTS
F63A   20 DB FC   JSR $FCDB
F63D   D0 E5      BNE $F624
F63F   20 FE ED   JSR $EDFE

; close serial bus device

F642   24 B9      BIT $B9
F644   30 11      BMI $F657
F646   A5 BA      LDA $BA
F648   20 0C ED   JSR $ED0C
F64B   A5 B9      LDA $B9
F64D   29 EF      AND #$EF
F64F   09 E0      ORA #$E0
F651   20 B9 ED   JSR $EDB9
F654   20 FE ED   JSR $EDFE
F657   18         CLC
F658   60         RTS
F659   4A         LSR
F65A   B0 03      BCS $F65F
F65C   4C 13 F7   JMP $F713

; save ram to cassette

F65F   20 D0 F7   JSR $F7D0
F662   90 8D      BCC $F5F1
F664   20 38 F8   JSR $F838
F667   B0 25      BCS $F68E
F669   20 8F F6   JSR $F68F
F66C   A2 03      LDX #$03
F66E   A5 B9      LDA $B9
F670   29 01      AND #$01
F672   D0 02      BNE $F676
F674   A2 01      LDX #$01
F676   8A         TXA
F677   20 6A F7   JSR $F76A
F67A   B0 12      BCS $F68E
F67C   20 67 F8   JSR $F867
F67F   B0 0D      BCS $F68E
F681   A5 B9      LDA $B9
F683   29 02      AND #$02
F685   F0 06      BEQ $F68D
F687   A9 05      LDA #$05
F689   20 6A F7   JSR $F76A
F68C   .BY $24
F68D   18         CLC
F68E   60         RTS

; do saving message and filename

F68F   A5 9D      LDA $9D
F691   10 FB      BPL $F68E
F693   A0 51      LDY #$51
F695   20 2F F1   JSR $F12F
F698   4C C1 F5   JMP $F5C1

; increment real time clock

F69B   A2 00      LDX #$00
F69D   E6 A2      INC $A2
F69F   D0 06      BNE $F6A7
F6A1   E6 A1      INC $A1
F6A3   D0 02      BNE $F6A7
F6A5   E6 A0      INC $A0
F6A7   38         SEC
F6A8   A5 A2      LDA $A2
F6AA   E9 01      SBC #$01
F6AC   A5 A1      LDA $A1
F6AE   E9 1A      SBC #$1A
F6B0   A5 A0      LDA $A0
F6B2   E9 4F      SBC #$4F
F6B4   90 06      BCC $F6BC
F6B6   86 A0      STX $A0
F6B8   86 A1      STX $A1
F6BA   86 A2      STX $A2
F6BC   AD 01 DC   LDA $DC01
F6BF   CD 01 DC   CMP $DC01
F6C2   D0 F8      BNE $F6BC
F6C4   AA         TAX
F6C5   30 13      BMI $F6DA
F6C7   A2 BD      LDX #$BD
F6C9   8E 00 DC   STX $DC00
F6CC   AE 01 DC   LDX $DC01
F6CF   EC 01 DC   CPX $DC01
F6D2   D0 F8      BNE $F6CC
F6D4   8D 00 DC   STA $DC00
F6D7   E8         INX
F6D8   D0 02      BNE $F6DC
F6DA   85 91      STA $91
F6DC   60         RTS

; read real time clock

F6DD   78         SEI
F6DE   A5 A2      LDA $A2
F6E0   A6 A1      LDX $A1
F6E2   A4 A0      LDY $A0

; set real time clock

F6E4   78         SEI
F6E5   85 A2      STA $A2
F6E7   86 A1      STX $A1
F6E9   84 A0      STY $A0
F6EB   58         CLI
F6EC   60         RTS

; test STOP key

F6ED   A5 91      LDA $91
F6EF   C9 7F      CMP #$7F
F6F1   D0 07      BNE $F6FA
F6F3   08         PHP
F6F4   20 CC FF   JSR $FFCC
F6F7   85 C6      STA $C6
F6F9   28         PLP
F6FA   60         RTS

; handle I/O errors

F6FB   A9 01      LDA #$01      ; too many files
F6FD   .BY $2C
F6FE   A9 02      LDA #$02      ; file open
F700   .BY $2C
F701   A9 03      LDA #$03      ; file not open
F703   .BY $2C
F704   A9 04      LDA #$04      ; file not found
F706   .BY $2C
F707   A9 05      LDA #$05      ; device not present
F709   .BY $2C
F70A   A9 06      LDA #$06      ; not input file
F70C   .BY $2C
F70D   A9 07      LDA #$07      ; not output file
F70F   .BY $2C
F710   A9 08      LDA #$08      ; file name missing
F712   .BY $2C
F713   A9 09      LDA #$09      ; illegal device no.
F715   48         PHA
F716   20 CC FF   JSR $FFCC
F719   A0 00      LDY #$00
F71B   24 9D      BIT $9D
F71D   50 0A      BVC $F729
F71F   20 2F F1   JSR $F12F
F722   68         PLA
F723   48         PHA
F724   09 30      ORA #$30
F726   20 D2 FF   JSR $FFD2
F729   68         PLA
F72A   38         SEC
F72B   60         RTS

; get next file header from cassette

F72C   A5 93      LDA $93
F72E   48         PHA
F72F   20 41 F8   JSR $F841
F732   68         PLA
F733   85 93      STA $93
F735   B0 32      BCS $F769
F737   A0 00      LDY #$00
F739   B1 B2      LDA ($B2),Y
F73B   C9 05      CMP #$05
F73D   F0 2A      BEQ $F769
F73F   C9 01      CMP #$01
F741   F0 08      BEQ $F74B
F743   C9 03      CMP #$03
F745   F0 04      BEQ $F74B
F747   C9 04      CMP #$04
F749   D0 E1      BNE $F72C
F74B   AA         TAX
F74C   24 9D      BIT $9D
F74E   10 17      BPL $F767
F750   A0 63      LDY #$63
F752   20 2F F1   JSR $F12F
F755   A0 05      LDY #$05
F757   B1 B2      LDA ($B2),Y
F759   20 D2 FF   JSR $FFD2
F75C   C8         INY
F75D   C0 15      CPY #$15
F75F   D0 F6      BNE $F757
F761   A5 A1      LDA $A1
F763   20 E0 E4   JSR $E4E0
F766   EA         NOP
F767   18         CLC
F768   88         DEY
F769   60         RTS

; write a special block to cassette with code in A

F76A   85 9E      STA $9E
F76C   20 D0 F7   JSR $F7D0
F76F   90 5E      BCC $F7CF
F771   A5 C2      LDA $C2
F773   48         PHA
F774   A5 C1      LDA $C1
F776   48         PHA
F777   A5 AF      LDA $AF
F779   48         PHA
F77A   A5 AE      LDA $AE
F77C   48         PHA
F77D   A0 BF      LDY #$BF
F77F   A9 20      LDA #$20
F781   91 B2      STA ($B2),Y
F783   88         DEY
F784   D0 FB      BNE $F781
F786   A5 9E      LDA $9E
F788   91 B2      STA ($B2),Y
F78A   C8         INY
F78B   A5 C1      LDA $C1
F78D   91 B2      STA ($B2),Y
F78F   C8         INY
F790   A5 C2      LDA $C2
F792   91 B2      STA ($B2),Y
F794   C8         INY
F795   A5 AE      LDA $AE
F797   91 B2      STA ($B2),Y
F799   C8         INY
F79A   A5 AF      LDA $AF
F79C   91 B2      STA ($B2),Y
F79E   C8         INY
F79F   84 9F      STY $9F
F7A1   A0 00      LDY #$00
F7A3   84 9E      STY $9E
F7A5   A4 9E      LDY $9E
F7A7   C4 B7      CPY $B7
F7A9   F0 0C      BEQ $F7B7
F7AB   B1 BB      LDA ($BB),Y
F7AD   A4 9F      LDY $9F
F7AF   91 B2      STA ($B2),Y
F7B1   E6 9E      INC $9E
F7B3   E6 9F      INC $9F
F7B5   D0 EE      BNE $F7A5
F7B7   20 D7 F7   JSR $F7D7
F7BA   A9 69      LDA #$69
F7BC   85 AB      STA $AB
F7BE   20 6B F8   JSR $F86B
F7C1   A8         TAY
F7C2   68         PLA
F7C3   85 AE      STA $AE
F7C5   68         PLA
F7C6   85 AF      STA $AF
F7C8   68         PLA
F7C9   85 C1      STA $C1
F7CB   68         PLA
F7CC   85 C2      STA $C2
F7CE   98         TYA
F7CF   60         RTS

; set tape buffer pointer in XY

F7D0   A6 B2      LDX $B2
F7D2   A4 B3      LDY $B3
F7D4   C0 02      CPY #$02
F7D6   60         RTS

; set cassette buffer to I/O area

F7D7   20 D0 F7   JSR $F7D0
F7DA   8A         TXA
F7DB   85 C1      STA $C1
F7DD   18         CLC
F7DE   69 C0      ADC #$C0
F7E0   85 AE      STA $AE
F7E2   98         TYA
F7E3   85 C2      STA $C2
F7E5   69 00      ADC #$00
F7E7   85 AF      STA $AF
F7E9   60         RTS

; search tape for a file name

F7EA   20 2C F7   JSR $F72C
F7ED   B0 1D      BCS $F80C
F7EF   A0 05      LDY #$05
F7F1   84 9F      STY $9F
F7F3   A0 00      LDY #$00
F7F5   84 9E      STY $9E
F7F7   C4 B7      CPY $B7
F7F9   F0 10      BEQ $F80B
F7FB   B1 BB      LDA ($BB),Y
F7FD   A4 9F      LDY $9F
F7FF   D1 B2      CMP ($B2),Y
F801   D0 E7      BNE $F7EA
F803   E6 9E      INC $9E
F805   E6 9F      INC $9F
F807   A4 9E      LDY $9E
F809   D0 EC      BNE $F7F7
F80B   18         CLC
F80C   60         RTS

; add 1 to tape index and test for overflow

F80D   20 D0 F7   JSR $F7D0
F810   E6 A6      INC $A6
F812   A4 A6      LDY $A6
F814   C0 C0      CPY #$C0
F816   60         RTS

; handle messages and test cassette buttons for read

F817   20 2E F8   JSR $F82E
F81A   F0 1A      BEQ $F836
F81C   A0 1B      LDY #$1B
F81E   20 2F F1   JSR $F12F
F821   20 D0 F8   JSR $F8D0
F824   20 2E F8   JSR $F82E
F827   D0 F8      BNE $F821
F829   A0 6A      LDY #$6A
F82B   4C 2F F1   JMP $F12F

; test sense line for a button depressed on cassette

F82E   A9 10      LDA #$10
F830   24 01      BIT $01
F832   D0 02      BNE $F836
F834   24 01      BIT $01
F836   18         CLC
F837   60         RTS

; set messages and test cassette line for input

F838   20 2E F8   JSR $F82E
F83B   F0 F9      BEQ $F836
F83D   A0 2E      LDY #$2E
F83F   D0 DD      BNE $F81E

; read a block from cassette

F841   A9 00      LDA #$00
F843   85 90      STA $90
F845   85 93      STA $93
F847   20 D7 F7   JSR $F7D7
F84A   20 17 F8   JSR $F817
F84D   B0 1F      BCS $F86E
F84F   78         SEI
F850   A9 00      LDA #$00
F852   85 AA      STA $AA
F854   85 B4      STA $B4
F856   85 B0      STA $B0
F858   85 9E      STA $9E
F85A   85 9F      STA $9F
F85C   85 9C      STA $9C
F85E   A9 90      LDA #$90
F860   A2 0E      LDX #$0E
F862   D0 11      BNE $F875

; write a block from cassette

F864   20 D7 F7   JSR $F7D7
F867   A9 14      LDA #$14
F869   85 AB      STA $AB
F86B   20 38 F8   JSR $F838
F86E   B0 6C      BCS $F8DC
F870   78         SEI
F871   A9 82      LDA #$82
F873   A2 08      LDX #$08

; common code for cassette read and write

F875   A0 7F      LDY #$7F
F877   8C 0D DC   STY $DC0D
F87A   8D 0D DC   STA $DC0D
F87D   AD 0E DC   LDA $DC0E
F880   09 19      ORA #$19
F882   8D 0F DC   STA $DC0F
F885   29 91      AND #$91
F887   8D A2 02   STA $02A2
F88A   20 A4 F0   JSR $F0A4
F88D   AD 11 D0   LDA $D011
F890   29 EF      AND #$EF
F892   8D 11 D0   STA $D011
F895   AD 14 03   LDA $0314
F898   8D 9F 02   STA $029F
F89B   AD 15 03   LDA $0315
F89E   8D A0 02   STA $02A0
F8A1   20 BD FC   JSR $FCBD
F8A4   A9 02      LDA #$02
F8A6   85 BE      STA $BE
F8A8   20 97 FB   JSR $FB97
F8AB   A5 01      LDA $01
F8AD   29 1F      AND #$1F
F8AF   85 01      STA $01
F8B1   85 C0      STA $C0
F8B3   A2 FF      LDX #$FF
F8B5   A0 FF      LDY #$FF
F8B7   88         DEY
F8B8   D0 FD      BNE $F8B7
F8BA   CA         DEX
F8BB   D0 F8      BNE $F8B5
F8BD   58         CLI
F8BE   AD A0 02   LDA $02A0
F8C1   CD 15 03   CMP $0315
F8C4   18         CLC
F8C5   F0 15      BEQ $F8DC
F8C7   20 D0 F8   JSR $F8D0
F8CA   20 BC F6   JSR $F6BC
F8CD   4C BE F8   JMP $F8BE

; handle stop key during cassette operations

F8D0   20 E1 FF   JSR $FFE1
F8D3   18         CLC
F8D4   D0 0B      BNE $F8E1
F8D6   20 93 FC   JSR $FC93
F8D9   38         SEC
F8DA   68         PLA
F8DB   68         PLA
F8DC   A9 00      LDA #$00
F8DE   8D A0 02   STA $02A0
F8E1   60         RTS

; schedule CIA 1 timer A depending on X

F8E2   86 B1      STX $B1
F8E4   A5 B0      LDA $B0
F8E6   0A         ASL
F8E7   0A         ASL
F8E8   18         CLC
F8E9   65 B0      ADC $B0
F8EB   18         CLC
F8EC   65 B1      ADC $B1
F8EE   85 B1      STA $B1
F8F0   A9 00      LDA #$00
F8F2   24 B0      BIT $B0
F8F4   30 01      BMI $F8F7
F8F6   2A         ROL
F8F7   06 B1      ASL $B1
F8F9   2A         ROL
F8FA   06 B1      ASL $B1
F8FC   2A         ROL
F8FD   AA         TAX
F8FE   AD 06 DC   LDA $DC06
F901   C9 16      CMP #$16
F903   90 F9      BCC $F8FE
F905   65 B1      ADC $B1
F907   8D 04 DC   STA $DC04
F90A   8A         TXA
F90B   6D 07 DC   ADC $DC07
F90E   8D 05 DC   STA $DC05
F911   AD A2 02   LDA $02A2
F914   8D 0E DC   STA $DC0E
F917   8D A4 02   STA $02A4
F91A   AD 0D DC   LDA $DC0D
F91D   29 10      AND #$10
F91F   F0 09      BEQ $F92A
F921   A9 F9      LDA #$F9
F923   48         PHA
F924   A9 2A      LDA #$2A
F926   48         PHA
F927   4C 43 FF   JMP $FF43
F92A   58         CLI
F92B   60         RTS

; cassette read IRQ routine

F92C   AE 07 DC   LDX $DC07
F92F   A0 FF      LDY #$FF
F931   98         TYA
F932   ED 06 DC   SBC $DC06
F935   EC 07 DC   CPX $DC07
F938   D0 F2      BNE $F92C
F93A   86 B1      STX $B1
F93C   AA         TAX
F93D   8C 06 DC   STY $DC06
F940   8C 07 DC   STY $DC07
F943   A9 19      LDA #$19
F945   8D 0F DC   STA $DC0F
F948   AD 0D DC   LDA $DC0D
F94B   8D A3 02   STA $02A3
F94E   98         TYA
F94F   E5 B1      SBC $B1
F951   86 B1      STX $B1
F953   4A         LSR
F954   66 B1      ROR $B1
F956   4A         LSR
F957   66 B1      ROR $B1
F959   A5 B0      LDA $B0
F95B   18         CLC
F95C   69 3C      ADC #$3C
F95E   C5 B1      CMP $B1
F960   B0 4A      BCS $F9AC
F962   A6 9C      LDX $9C
F964   F0 03      BEQ $F969
F966   4C 60 FA   JMP $FA60
F969   A6 A3      LDX $A3
F96B   30 1B      BMI $F988
F96D   A2 00      LDX #$00
F96F   69 30      ADC #$30
F971   65 B0      ADC $B0
F973   C5 B1      CMP $B1
F975   B0 1C      BCS $F993
F977   E8         INX
F978   69 26      ADC #$26
F97A   65 B0      ADC $B0
F97C   C5 B1      CMP $B1
F97E   B0 17      BCS $F997
F980   69 2C      ADC #$2C
F982   65 B0      ADC $B0
F984   C5 B1      CMP $B1
F986   90 03      BCC $F98B
F988   4C 10 FA   JMP $FA10
F98B   A5 B4      LDA $B4
F98D   F0 1D      BEQ $F9AC
F98F   85 A8      STA $A8
F991   D0 19      BNE $F9AC
F993   E6 A9      INC $A9
F995   B0 02      BCS $F999
F997   C6 A9      DEC $A9
F999   38         SEC
F99A   E9 13      SBC #$13
F99C   E5 B1      SBC $B1
F99E   65 92      ADC $92
F9A0   85 92      STA $92
F9A2   A5 A4      LDA $A4
F9A4   49 01      EOR #$01
F9A6   85 A4      STA $A4
F9A8   F0 2B      BEQ $F9D5
F9AA   86 D7      STX $D7
F9AC   A5 B4      LDA $B4
F9AE   F0 22      BEQ $F9D2
F9B0   AD A3 02   LDA $02A3
F9B3   29 01      AND #$01
F9B5   D0 05      BNE $F9BC
F9B7   AD A4 02   LDA $02A4
F9BA   D0 16      BNE $F9D2
F9BC   A9 00      LDA #$00
F9BE   85 A4      STA $A4
F9C0   8D A4 02   STA $02A4
F9C3   A5 A3      LDA $A3
F9C5   10 30      BPL $F9F7
F9C7   30 BF      BMI $F988
F9C9   A2 A6      LDX #$A6
F9CB   20 E2 F8   JSR $F8E2
F9CE   A5 9B      LDA $9B
F9D0   D0 B9      BNE $F98B
F9D2   4C BC FE   JMP $FEBC
F9D5   A5 92      LDA $92
F9D7   F0 07      BEQ $F9E0
F9D9   30 03      BMI $F9DE
F9DB   C6 B0      DEC $B0
F9DD   .BY $2C
F9DE   E6 B0      INC $B0
F9E0   A9 00      LDA #$00
F9E2   85 92      STA $92
F9E4   E4 D7      CPX $D7
F9E6   D0 0F      BNE $F9F7
F9E8   8A         TXA
F9E9   D0 A0      BNE $F98B
F9EB   A5 A9      LDA $A9
F9ED   30 BD      BMI $F9AC
F9EF   C9 10      CMP #$10
F9F1   90 B9      BCC $F9AC
F9F3   85 96      STA $96
F9F5   B0 B5      BCS $F9AC
F9F7   8A         TXA
F9F8   45 9B      EOR $9B
F9FA   85 9B      STA $9B
F9FC   A5 B4      LDA $B4
F9FE   F0 D2      BEQ $F9D2
FA00   C6 A3      DEC $A3
FA02   30 C5      BMI $F9C9
FA04   46 D7      LSR $D7
FA06   66 BF      ROR $BF
FA08   A2 DA      LDX #$DA
FA0A   20 E2 F8   JSR $F8E2
FA0D   4C BC FE   JMP $FEBC
FA10   A5 96      LDA $96
FA12   F0 04      BEQ $FA18
FA14   A5 B4      LDA $B4
FA16   F0 07      BEQ $FA1F
FA18   A5 A3      LDA $A3
FA1A   30 03      BMI $FA1F
FA1C   4C 97 F9   JMP $F997
FA1F   46 B1      LSR $B1
FA21   A9 93      LDA #$93
FA23   38         SEC
FA24   E5 B1      SBC $B1
FA26   65 B0      ADC $B0
FA28   0A         ASL
FA29   AA         TAX
FA2A   20 E2 F8   JSR $F8E2
FA2D   E6 9C      INC $9C
FA2F   A5 B4      LDA $B4
FA31   D0 11      BNE $FA44
FA33   A5 96      LDA $96
FA35   F0 26      BEQ $FA5D
FA37   85 A8      STA $A8
FA39   A9 00      LDA #$00
FA3B   85 96      STA $96
FA3D   A9 81      LDA #$81
FA3F   8D 0D DC   STA $DC0D
FA42   85 B4      STA $B4
FA44   A5 96      LDA $96
FA46   85 B5      STA $B5
FA48   F0 09      BEQ $FA53
FA4A   A9 00      LDA #$00
FA4C   85 B4      STA $B4
FA4E   A9 01      LDA #$01
FA50   8D 0D DC   STA $DC0D
FA53   A5 BF      LDA $BF
FA55   85 BD      STA $BD
FA57   A5 A8      LDA $A8
FA59   05 A9      ORA $A9
FA5B   85 B6      STA $B6
FA5D   4C BC FE   JMP $FEBC

; receive next byte from cassette

FA60   20 97 FB   JSR $FB97
FA63   85 9C      STA $9C
FA65   A2 DA      LDX #$DA
FA67   20 E2 F8   JSR $F8E2
FA6A   A5 BE      LDA $BE
FA6C   F0 02      BEQ $FA70
FA6E   85 A7      STA $A7
FA70   A9 0F      LDA #$0F
FA72   24 AA      BIT $AA
FA74   10 17      BPL $FA8D
FA76   A5 B5      LDA $B5
FA78   D0 0C      BNE $FA86
FA7A   A6 BE      LDX $BE
FA7C   CA         DEX
FA7D   D0 0B      BNE $FA8A
FA7F   A9 08      LDA #$08
FA81   20 1C FE   JSR $FE1C
FA84   D0 04      BNE $FA8A
FA86   A9 00      LDA #$00
FA88   85 AA      STA $AA
FA8A   4C BC FE   JMP $FEBC
FA8D   70 31      BVS $FAC0
FA8F   D0 18      BNE $FAA9
FA91   A5 B5      LDA $B5
FA93   D0 F5      BNE $FA8A
FA95   A5 B6      LDA $B6
FA97   D0 F1      BNE $FA8A
FA99   A5 A7      LDA $A7
FA9B   4A         LSR
FA9C   A5 BD      LDA $BD
FA9E   30 03      BMI $FAA3
FAA0   90 18      BCC $FABA
FAA2   18         CLC
FAA3   B0 15      BCS $FABA
FAA5   29 0F      AND #$0F
FAA7   85 AA      STA $AA
FAA9   C6 AA      DEC $AA
FAAB   D0 DD      BNE $FA8A
FAAD   A9 40      LDA #$40
FAAF   85 AA      STA $AA
FAB1   20 8E FB   JSR $FB8E
FAB4   A9 00      LDA #$00
FAB6   85 AB      STA $AB
FAB8   F0 D0      BEQ $FA8A
FABA   A9 80      LDA #$80
FABC   85 AA      STA $AA
FABE   D0 CA      BNE $FA8A
FAC0   A5 B5      LDA $B5
FAC2   F0 0A      BEQ $FACE
FAC4   A9 04      LDA #$04
FAC6   20 1C FE   JSR $FE1C
FAC9   A9 00      LDA #$00
FACB   4C 4A FB   JMP $FB4A
FACE   20 D1 FC   JSR $FCD1
FAD1   90 03      BCC $FAD6
FAD3   4C 48 FB   JMP $FB48
FAD6   A6 A7      LDX $A7
FAD8   CA         DEX
FAD9   F0 2D      BEQ $FB08
FADB   A5 93      LDA $93
FADD   F0 0C      BEQ $FAEB
FADF   A0 00      LDY #$00
FAE1   A5 BD      LDA $BD
FAE3   D1 AC      CMP ($AC),Y
FAE5   F0 04      BEQ $FAEB
FAE7   A9 01      LDA #$01
FAE9   85 B6      STA $B6
FAEB   A5 B6      LDA $B6
FAED   F0 4B      BEQ $FB3A
FAEF   A2 3D      LDX #$3D
FAF1   E4 9E      CPX $9E
FAF3   90 3E      BCC $FB33
FAF5   A6 9E      LDX $9E
FAF7   A5 AD      LDA $AD
FAF9   9D 01 01   STA $0101,X
FAFC   A5 AC      LDA $AC
FAFE   9D 00 01   STA $0100,X
FB01   E8         INX
FB02   E8         INX
FB03   86 9E      STX $9E
FB05   4C 3A FB   JMP $FB3A
FB08   A6 9F      LDX $9F
FB0A   E4 9E      CPX $9E
FB0C   F0 35      BEQ $FB43
FB0E   A5 AC      LDA $AC
FB10   DD 00 01   CMP $0100,X
FB13   D0 2E      BNE $FB43
FB15   A5 AD      LDA $AD
FB17   DD 01 01   CMP $0101,X
FB1A   D0 27      BNE $FB43
FB1C   E6 9F      INC $9F
FB1E   E6 9F      INC $9F
FB20   A5 93      LDA $93
FB22   F0 0B      BEQ $FB2F
FB24   A5 BD      LDA $BD
FB26   A0 00      LDY #$00
FB28   D1 AC      CMP ($AC),Y
FB2A   F0 17      BEQ $FB43
FB2C   C8         INY
FB2D   84 B6      STY $B6
FB2F   A5 B6      LDA $B6
FB31   F0 07      BEQ $FB3A
FB33   A9 10      LDA #$10
FB35   20 1C FE   JSR $FE1C
FB38   D0 09      BNE $FB43
FB3A   A5 93      LDA $93
FB3C   D0 05      BNE $FB43
FB3E   A8         TAY
FB3F   A5 BD      LDA $BD
FB41   91 AC      STA ($AC),Y
FB43   20 DB FC   JSR $FCDB
FB46   D0 43      BNE $FB8B
FB48   A9 80      LDA #$80
FB4A   85 AA      STA $AA
FB4C   78         SEI
FB4D   A2 01      LDX #$01
FB4F   8E 0D DC   STX $DC0D
FB52   AE 0D DC   LDX $DC0D
FB55   A6 BE      LDX $BE
FB57   CA         DEX
FB58   30 02      BMI $FB5C
FB5A   86 BE      STX $BE
FB5C   C6 A7      DEC $A7
FB5E   F0 08      BEQ $FB68
FB60   A5 9E      LDA $9E
FB62   D0 27      BNE $FB8B
FB64   85 BE      STA $BE
FB66   F0 23      BEQ $FB8B
FB68   20 93 FC   JSR $FC93
FB6B   20 8E FB   JSR $FB8E
FB6E   A0 00      LDY #$00
FB70   84 AB      STY $AB
FB72   B1 AC      LDA ($AC),Y
FB74   45 AB      EOR $AB
FB76   85 AB      STA $AB
FB78   20 DB FC   JSR $FCDB
FB7B   20 D1 FC   JSR $FCD1
FB7E   90 F2      BCC $FB72
FB80   A5 AB      LDA $AB
FB82   45 BD      EOR $BD
FB84   F0 05      BEQ $FB8B
FB86   A9 20      LDA #$20
FB88   20 1C FE   JSR $FE1C
FB8B   4C BC FE   JMP $FEBC

; move save/load address into $AC/$AD

FB8E   A5 C2      LDA $C2
FB90   85 AD      STA $AD
FB92   A5 C1      LDA $C1
FB94   85 AC      STA $AC
FB96   60         RTS

; initalise cassette read/write variables

FB97   A9 08      LDA #$08
FB99   85 A3      STA $A3
FB9B   A9 00      LDA #$00
FB9D   85 A4      STA $A4
FB9F   85 A8      STA $A8
FBA1   85 9B      STA $9B
FBA3   85 A9      STA $A9
FBA5   60         RTS

; schedule CIA 1 timer B and invert casette write line

FBA6   A5 BD      LDA $BD
FBA8   4A         LSR
FBA9   A9 60      LDA #$60
FBAB   90 02      BCC $FBAF
FBAD   A9 B0      LDA #$B0
FBAF   A2 00      LDX #$00
FBB1   8D 06 DC   STA $DC06
FBB4   8E 07 DC   STX $DC07
FBB7   AD 0D DC   LDA $DC0D
FBBA   A9 19      LDA #$19
FBBC   8D 0F DC   STA $DC0F
FBBF   A5 01      LDA $01
FBC1   49 08      EOR #$08
FBC3   85 01      STA $01
FBC5   29 08      AND #$08
FBC7   60         RTS

; IRQ routine for cassette write B

FBC8   38         SEC
FBC9   66 B6      ROR $B6
FBCB   30 3C      BMI $FC09
FBCD   A5 A8      LDA $A8
FBCF   D0 12      BNE $FBE3
FBD1   A9 10      LDA #$10
FBD3   A2 01      LDX #$01
FBD5   20 B1 FB   JSR $FBB1
FBD8   D0 2F      BNE $FC09
FBDA   E6 A8      INC $A8
FBDC   A5 B6      LDA $B6
FBDE   10 29      BPL $FC09
FBE0   4C 57 FC   JMP $FC57
FBE3   A5 A9      LDA $A9
FBE5   D0 09      BNE $FBF0
FBE7   20 AD FB   JSR $FBAD
FBEA   D0 1D      BNE $FC09
FBEC   E6 A9      INC $A9
FBEE   D0 19      BNE $FC09
FBF0   20 A6 FB   JSR $FBA6
FBF3   D0 14      BNE $FC09
FBF5   A5 A4      LDA $A4
FBF7   49 01      EOR #$01
FBF9   85 A4      STA $A4
FBFB   F0 0F      BEQ $FC0C
FBFD   A5 BD      LDA $BD
FBFF   49 01      EOR #$01
FC01   85 BD      STA $BD
FC03   29 01      AND #$01
FC05   45 9B      EOR $9B
FC07   85 9B      STA $9B
FC09   4C BC FE   JMP $FEBC
FC0C   46 BD      LSR $BD
FC0E   C6 A3      DEC $A3
FC10   A5 A3      LDA $A3
FC12   F0 3A      BEQ $FC4E
FC14   10 F3      BPL $FC09
FC16   20 97 FB   JSR $FB97
FC19   58         CLI
FC1A   A5 A5      LDA $A5
FC1C   F0 12      BEQ $FC30
FC1E   A2 00      LDX #$00
FC20   86 D7      STX $D7
FC22   C6 A5      DEC $A5
FC24   A6 BE      LDX $BE
FC26   E0 02      CPX #$02
FC28   D0 02      BNE $FC2C
FC2A   09 80      ORA #$80
FC2C   85 BD      STA $BD
FC2E   D0 D9      BNE $FC09
FC30   20 D1 FC   JSR $FCD1
FC33   90 0A      BCC $FC3F
FC35   D0 91      BNE $FBC8
FC37   E6 AD      INC $AD
FC39   A5 D7      LDA $D7
FC3B   85 BD      STA $BD
FC3D   B0 CA      BCS $FC09
FC3F   A0 00      LDY #$00
FC41   B1 AC      LDA ($AC),Y
FC43   85 BD      STA $BD
FC45   45 D7      EOR $D7
FC47   85 D7      STA $D7
FC49   20 DB FC   JSR $FCDB
FC4C   D0 BB      BNE $FC09
FC4E   A5 9B      LDA $9B
FC50   49 01      EOR #$01
FC52   85 BD      STA $BD
FC54   4C BC FE   JMP $FEBC
FC57   C6 BE      DEC $BE
FC59   D0 03      BNE $FC5E
FC5B   20 CA FC   JSR $FCCA
FC5E   A9 50      LDA #$50
FC60   85 A7      STA $A7
FC62   A2 08      LDX #$08
FC64   78         SEI
FC65   20 BD FC   JSR $FCBD
FC68   D0 EA      BNE $FC54

; IRQ routine for cassette write A

FC6A   A9 78      LDA #$78
FC6C   20 AF FB   JSR $FBAF
FC6F   D0 E3      BNE $FC54
FC71   C6 A7      DEC $A7
FC73   D0 DF      BNE $FC54
FC75   20 97 FB   JSR $FB97
FC78   C6 AB      DEC $AB
FC7A   10 D8      BPL $FC54
FC7C   A2 0A      LDX #$0A
FC7E   20 BD FC   JSR $FCBD
FC81   58         CLI
FC82   E6 AB      INC $AB
FC84   A5 BE      LDA $BE
FC86   F0 30      BEQ $FCB8
FC88   20 8E FB   JSR $FB8E
FC8B   A2 09      LDX #$09
FC8D   86 A5      STX $A5
FC8F   86 B6      STX $B6
FC91   D0 83      BNE $FC16

; switch from cassette IRQ to default IRQ

FC93   08         PHP
FC94   78         SEI
FC95   AD 11 D0   LDA $D011
FC98   09 10      ORA #$10
FC9A   8D 11 D0   STA $D011
FC9D   20 CA FC   JSR $FCCA
FCA0   A9 7F      LDA #$7F
FCA2   8D 0D DC   STA $DC0D
FCA5   20 DD FD   JSR $FDDD
FCA8   AD A0 02   LDA $02A0
FCAB   F0 09      BEQ $FCB6
FCAD   8D 15 03   STA $0315
FCB0   AD 9F 02   LDA $029F
FCB3   8D 14 03   STA $0314
FCB6   28         PLP
FCB7   60         RTS

; terminate cassette I/O

FCB8   20 93 FC   JSR $FC93
FCBB   F0 97      BEQ $FC54

; set IRQ vector depending on X

FCBD   BD 93 FD   LDA $FD93,X
FCC0   8D 14 03   STA $0314
FCC3   BD 94 FD   LDA $FD94,X
FCC6   8D 15 03   STA $0315
FCC9   60         RTS

; stop cassette motor

FCCA   A5 01      LDA $01
FCCC   09 20      ORA #$20
FCCE   85 01      STA $01
FCD0   60         RTS

; compare $AC/$AD with $AE/$AF

FCD1   38         SEC
FCD2   A5 AC      LDA $AC
FCD4   E5 AE      SBC $AE
FCD6   A5 AD      LDA $AD
FCD8   E5 AF      SBC $AF
FCDA   60         RTS

; increment $AC/$AD

FCDB   E6 AC      INC $AC
FCDD   D0 02      BNE $FCE1
FCDF   E6 AD      INC $AD
FCE1   60         RTS

; RESET routine

FCE2   A2 FF      LDX #$FF
FCE4   78         SEI
FCE5   9A         TXS
FCE6   D8         CLD
FCE7   20 02 FD   JSR $FD02
FCEA   D0 03      BNE $FCEF
FCEC   6C 00 80   JMP ($8000)   ; start cartridge
FCEF   8E 16 D0   STX $D016
FCF2   20 A3 FD   JSR $FDA3
FCF5   20 50 FD   JSR $FD50
FCF8   20 15 FD   JSR $FD15
FCFB   20 5B FF   JSR $FF5B
FCFE   58         CLI
FCFF   6C 00 A0   JMP ($A000)   ; start basic

; check for a cartridge

FD02   A2 05      LDX #$05
FD04   BD 0F FD   LDA $FD0F,X
FD07   DD 03 80   CMP $8003,X
FD0A   D0 03      BNE $FD0F
FD0C   CA         DEX
FD0D   D0 F5      BNE $FD04
FD0F   60         RTS

; CBM80

FD10   .BY $C3,$C2,$CD,$38,$30

; restore I/O vectors

FD15   A2 30      LDX #$30      ; low  FD30
FD17   A0 FD      LDY #$FD      ; high FD30
FD19   18         CLC

; set I/O vectors depending on XY

FD1A   86 C3      STX $C3
FD1C   84 C4      STY $C4
FD1E   A0 1F      LDY #$1F
FD20   B9 14 03   LDA $0314,Y
FD23   B0 02      BCS $FD27
FD25   B1 C3      LDA ($C3),Y
FD27   91 C3      STA ($C3),Y
FD29   99 14 03   STA $0314,Y
FD2C   88         DEY
FD2D   10 F1      BPL $FD20
FD2F   60         RTS

; vectors for OS at $0314-$0333

FD30   .WD $EA31   ; IRQ
FD32   .WD $FE66   ; BRK
FD34   .WD $FE47   ; NMI
FD36   .WD $F34A   ; open
FD38   .WD $F291   ; close
FD3A   .WD $F20E   ; set input dev
FD3C   .WD $F250   ; set output dev
FD3E   .WD $F333   ; restore I/O
FD40   .WD $F157   ; input
FD42   .WD $F1CA   ; output
FD44   .WD $F6ED   ; test stop key
FD46   .WD $F13E   ; get
FD48   .WD $F32F   ; abort I/O
FD4A   .WD $FE66   ; unused (BRK)
FD4C   .WD $F4A5   ; load ram
FD4E   .WD $F5ED   ; save ram

; initalise memory pointers

FD50   A9 00      LDA #$00
FD52   A8         TAY
FD53   99 02 00   STA $0002,Y
FD56   99 00 02   STA $0200,Y
FD59   99 00 03   STA $0300,Y
FD5C   C8         INY
FD5D   D0 F4      BNE $FD53
FD5F   A2 3C      LDX #$3C
FD61   A0 03      LDY #$03
FD63   86 B2      STX $B2
FD65   84 B3      STY $B3
FD67   A8         TAY
FD68   A9 03      LDA #$03
FD6A   85 C2      STA $C2
FD6C   E6 C2      INC $C2
FD6E   B1 C1      LDA ($C1),Y
FD70   AA         TAX
FD71   A9 55      LDA #$55
FD73   91 C1      STA ($C1),Y
FD75   D1 C1      CMP ($C1),Y
FD77   D0 0F      BNE $FD88
FD79   2A         ROL
FD7A   91 C1      STA ($C1),Y
FD7C   D1 C1      CMP ($C1),Y
FD7E   D0 08      BNE $FD88
FD80   8A         TXA
FD81   91 C1      STA ($C1),Y
FD83   C8         INY
FD84   D0 E8      BNE $FD6E
FD86   F0 E4      BEQ $FD6C
FD88   98         TYA
FD89   AA         TAX
FD8A   A4 C2      LDY $C2
FD8C   18         CLC
FD8D   20 2D FE   JSR $FE2D
FD90   A9 08      LDA #$08
FD92   8D 82 02   STA $0282
FD95   A9 04      LDA #$04
FD97   8D 88 02   STA $0288
FD9A   60         RTS

; IRQ vectors

FD9B   .WD $FC6A                ; cassette write A
FD9D   .WD $FBCD                ; cassette write B
FD9F   .WD $EA31                ; standard IRQ
FDA1   .WD $F92C                ; cassette read

; initaliase I/O devices

FDA3   A9 7F      LDA #$7F
FDA5   8D 0D DC   STA $DC0D
FDA8   8D 0D DD   STA $DD0D
FDAB   8D 00 DC   STA $DC00
FDAE   A9 08      LDA #$08
FDB0   8D 0E DC   STA $DC0E
FDB3   8D 0E DD   STA $DD0E
FDB6   8D 0F DC   STA $DC0F
FDB9   8D 0F DD   STA $DD0F
FDBC   A2 00      LDX #$00
FDBE   8E 03 DC   STX $DC03
FDC1   8E 03 DD   STX $DD03
FDC4   8E 18 D4   STX $D418
FDC7   CA         DEX
FDC8   8E 02 DC   STX $DC02
FDCB   A9 07      LDA #$07
FDCD   8D 00 DD   STA $DD00
FDD0   A9 3F      LDA #$3F
FDD2   8D 02 DD   STA $DD02
FDD5   A9 E7      LDA #$E7
FDD7   85 01      STA $01
FDD9   A9 2F      LDA #$2F
FDDB   85 00      STA $00

; initalise TAL1/TAH1 fpr 1/60 of a second

FDDD   AD A6 02   LDA $02A6
FDE0   F0 0A      BEQ $FDEC
FDE2   A9 25      LDA #$25
FDE4   8D 04 DC   STA $DC04
FDE7   A9 40      LDA #$40
FDE9   4C F3 FD   JMP $FDF3
FDEC   A9 95      LDA #$95
FDEE   8D 04 DC   STA $DC04
FDF1   A9 42      LDA #$42
FDF3   8D 05 DC   STA $DC05
FDF6   4C 6E FF   JMP $FF6E

; initalise file name parameters

FDF9   85 B7      STA $B7
FDFB   86 BB      STX $BB
FDFD   84 BC      STY $BC
FDFF   60         RTS

; inatalise file parameters

FE00   85 B8      STA $B8
FE02   86 BA      STX $BA
FE04   84 B9      STY $B9
FE06   60         RTS

; read I/O status word

FE07   A5 BA      LDA $BA
FE09   C9 02      CMP #$02
FE0B   D0 0D      BNE $FE1A
FE0D   AD 97 02   LDA $0297
FE10   48         PHA
FE11   A9 00      LDA #$00
FE13   8D 97 02   STA $0297
FE16   68         PLA
FE17   60         RTS

; control kernel messages

FE18   85 9D      STA $9D

; read ST

FE1A   A5 90      LDA $90

; add A to ST

FE1C   05 90      ORA $90
FE1E   85 90      STA $90
FE20   60         RTS

; set timeout on serail bus

FE21   8D 85 02   STA $0285
FE24   60         RTS

; read/set top of memory

FE25   90 06      BCC $FE2D
FE27   AE 83 02   LDX $0283
FE2A   AC 84 02   LDY $0284
FE2D   8E 83 02   STX $0283
FE30   8C 84 02   STY $0284
FE33   60         RTS

; read/set bottom of memory

FE34   90 06      BCC $FE3C
FE36   AE 81 02   LDX $0281
FE39   AC 82 02   LDY $0282
FE3C   8E 81 02   STX $0281
FE3F   8C 82 02   STY $0282
FE42   60         RTS

; NMI entry

FE43   78         SEI
FE44   6C 18 03   JMP ($0318)   ; normally FE47

; standard NMI routine

FE47   48         PHA
FE48   8A         TXA
FE49   48         PHA
FE4A   98         TYA
FE4B   48         PHA
FE4C   A9 7F      LDA #$7F
FE4E   8D 0D DD   STA $DD0D
FE51   AC 0D DD   LDY $DD0D
FE54   30 1C      BMI $FE72
FE56   20 02 FD   JSR $FD02
FE59   D0 03      BNE $FE5E
FE5B   6C 02 80   JMP ($8002)   ; cartridge warm start
FE5E   20 BC F6   JSR $F6BC
FE61   20 E1 FF   JSR $FFE1
FE64   D0 0C      BNE $FE72

; BRK routine

FE66   20 15 FD   JSR $FD15
FE69   20 A3 FD   JSR $FDA3
FE6C   20 18 E5   JSR $E518
FE6F   6C 02 A0   JMP ($A002)

; internal NMI

FE72   98         TYA
FE73   2D A1 02   AND $02A1
FE76   AA         TAX
FE77   29 01      AND #$01
FE79   F0 28      BEQ $FEA3
FE7B   AD 00 DD   LDA $DD00
FE7E   29 FB      AND #$FB
FE80   05 B5      ORA $B5
FE82   8D 00 DD   STA $DD00
FE85   AD A1 02   LDA $02A1
FE88   8D 0D DD   STA $DD0D
FE8B   8A         TXA
FE8C   29 12      AND #$12
FE8E   F0 0D      BEQ $FE9D
FE90   29 02      AND #$02
FE92   F0 06      BEQ $FE9A
FE94   20 D6 FE   JSR $FED6
FE97   4C 9D FE   JMP $FE9D
FE9A   20 07 FF   JSR $FF07
FE9D   20 BB EE   JSR $EEBB
FEA0   4C B6 FE   JMP $FEB6
FEA3   8A         TXA
FEA4   29 02      AND #$02
FEA6   F0 06      BEQ $FEAE
FEA8   20 D6 FE   JSR $FED6
FEAB   4C B6 FE   JMP $FEB6
FEAE   8A         TXA
FEAF   29 10      AND #$10
FEB1   F0 03      BEQ $FEB6
FEB3   20 07 FF   JSR $FF07
FEB6   AD A1 02   LDA $02A1
FEB9   8D 0D DD   STA $DD0D
FEBC   68         PLA
FEBD   A8         TAY
FEBE   68         PLA
FEBF   AA         TAX
FEC0   68         PLA
FEC1   40         RTI

; baud rate tables

FEC2   .WD $27C1                ; 50
FEC4   .WD $1A3E                ; 75
FEC6   .WD $11C5                ; 110
FEC8   .WD $0E74                ; 134.5
FECA   .WD $0CED                ; 150
FECC   .WD $0645                ; 300
FECE   .WD $02F0                ; 600
FED0   .WD $0146                ; 1200
FED2   .WD $00B8                ; 1800
FED4   .WD $0071                ; 2400

; input next bit on RS-232 and schedule TB2

FED6   AD 01 DD   LDA $DD01
FED9   29 01      AND #$01
FEDB   85 A7      STA $A7
FEDD   AD 06 DD   LDA $DD06
FEE0   E9 1C      SBC #$1C
FEE2   6D 99 02   ADC $0299
FEE5   8D 06 DD   STA $DD06
FEE8   AD 07 DD   LDA $DD07
FEEB   6D 9A 02   ADC $029A
FEEE   8D 07 DD   STA $DD07
FEF1   A9 11      LDA #$11
FEF3   8D 0F DD   STA $DD0F
FEF6   AD A1 02   LDA $02A1
FEF9   8D 0D DD   STA $DD0D
FEFC   A9 FF      LDA #$FF
FEFE   8D 06 DD   STA $DD06
FF01   8D 07 DD   STA $DD07
FF04   4C 59 EF   JMP $EF59

; schedule TB2 using baud rate factor

FF07   AD 95 02   LDA $0295
FF0A   8D 06 DD   STA $DD06
FF0D   AD 96 02   LDA $0296
FF10   8D 07 DD   STA $DD07
FF13   A9 11      LDA #$11
FF15   8D 0F DD   STA $DD0F
FF18   A9 12      LDA #$12
FF1A   4D A1 02   EOR $02A1
FF1D   8D A1 02   STA $02A1
FF20   A9 FF      LDA #$FF
FF22   8D 06 DD   STA $DD06
FF25   8D 07 DD   STA $DD07
FF28   AE 98 02   LDX $0298
FF2B   86 A8      STX $A8
FF2D   60         RTS

; continuation of baud rate calculation

FF2E   AA         TAX
FF2F   AD 96 02   LDA $0296
FF32   2A         ROL
FF33   A8         TAY
FF34   8A         TXA
FF35   69 C8      ADC #$C8
FF37   8D 99 02   STA $0299
FF3A   98         TYA
FF3B   69 00      ADC #$00
FF3D   8D 9A 02   STA $029A
FF40   60         RTS
FF41   EA         NOP
FF42   EA         NOP
FF43   08         PHP
FF44   68         PLA
FF45   29 EF      AND #$EF
FF47   48         PHA

; IRQ entry point

FF48   48         PHA
FF49   8A         TXA
FF4A   48         PHA
FF4B   98         TYA
FF4C   48         PHA
FF4D   BA         TSX
FF4E   BD 04 01   LDA $0104,X
FF51   29 10      AND #$10
FF53   F0 03      BEQ $FF58
FF55   6C 16 03   JMP ($0316)   ; normally FE66
FF58   6C 14 03   JMP ($0314)   ; normally EA31

; addition to I/O device initalisation

FF5B   20 18 E5   JSR $E518
FF5E   AD 12 D0   LDA $D012
FF61   D0 FB      BNE $FF5E
FF63   AD 19 D0   LDA $D019
FF66   29 01      AND #$01
FF68   8D A6 02   STA $02A6
FF6B   4C DD FD   JMP $FDDD

; end of scheduling TA for 1/60 second IRQ's

FF6E   A9 81      LDA #$81
FF70   8D 0D DC   STA $DC0D
FF73   AD 0E DC   LDA $DC0E
FF76   29 80      AND #$80
FF78   09 11      ORA #$11
FF7A   8D 0E DC   STA $DC0E
FF7D   4C 8E EE   JMP $EE8E

; kernal version number

FF80   .BY $03

; kernal vectors

FF81   4C 5B FF   JMP $FF5B     ; initalise screen and keyboard
FF84   4C A3 FD   JMP $FDA3     ; initalise I/O devices
FF87   4C 50 FD   JMP $FD50     ; initalise memory pointers
FF8A   4C 15 FD   JMP $FD15     ; restore I/O vectors
FF8D   4C 1A FD   JMP $FD1A     ; set I/O vectors from XY
FF90   4C 18 FE   JMP $FE18     ; control kernal messages
FF93   4C B9 ED   JMP $EDB9     ; read secondary address after listen
FF96   4C C7 ED   JMP $EDC7     ; read secondary address after talk
FF99   4C 25 FE   JMP $FE25     ; read/set top of memory
FF9C   4C 34 FE   JMP $FE34     ; read/set bottom of memory
FF9F   4C 87 EA   JMP $EA87     ; scan keyboard
FFA2   4C 21 FE   JMP $FE21     ; set timout for serial bus
FFA5   4C 13 EE   JMP $EE13     ; input on serial bus
FFA8   4C DD ED   JMP $EDDD     ; output byte on serial bus
FFAB   4C EF ED   JMP $EDEF     ; send untalk on serial bus
FFAE   4C FE ED   JMP $EDFE     ; send unlisten on serial bus
FFB1   4C 0C ED   JMP $ED0C     ; send listen on serial bus
FFB4   4C 09 ED   JMP $ED09     ; send talk on serial bus
FFB7   4C 07 FE   JMP $FE07     ; read I/O status word
FFBA   4C 00 FE   JMP $FE00     ; set file parameters
FFBD   4C F9 FD   JMP $FDF9     ; set filename parameters
FFC0   6C 1A 03   JMP ($031A)   ; (F34A) open a file
FFC3   6C 1C 03   JMP ($031C)   ; (F291) close a file
FFC6   6C 1E 03   JMP ($031E)   ; (F20E) set input device
FFC9   6C 20 03   JMP ($0320)   ; (F250) set output device
FFCC   6C 22 03   JMP ($0322)   ; (F333) restore I/O devices to default
FFCF   6C 24 03   JMP ($0324)   ; (F157) input char on current device
FFD2   6C 26 03   JMP ($0326)   ; (F1CA) output char on current device
FFD5   4C 9E F4   JMP $F49E     ; load ram from device
FFD8   4C DD F5   JMP $F5DD     ; save ram to device
FFDB   4C E4 F6   JMP $F6E4     ; set real time clock
FFDE   4C DD F6   JMP $F6DD     ; read real time clock
FFE1   6C 28 03   JMP ($0328)   ; (F6ED) check stop key
FFE4   6C 2A 03   JMP ($032A)   ; (F13E) get a character
FFE7   6C 2C 03   JMP ($032C)   ; (F32F) close all channels and files
FFEA   4C 9B F6   JMP $F69B     ; increment real time clock
FFED   4C 05 E5   JMP $E505     ; read organisation of screen into XY
FFF0   4C 0A E5   JMP $E50A     ; read/set XY cursor position
FFF3   4C 00 E5   JMP $E500     ; read base address of I/O devices

; vectors

FFF6   .BY $52,$52,$42,$59      ; unused
FFFA   .WD $FE43                ; NMI vector
FFFC   .WD $FCE2                ; RESET vector
FFFE   .WD $FF48                ; IRQ/BRK vector