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Now there's a listing of the program that contain the instruction to
read this format. The fields that depends by the particular game that are
loading are removed.
The load routine uses screen loading border effect.
This program is also autostarting (see location 0302h) and the loaded
program is automatically execute (location 03F5 RTI), becouse it pass the cpu
control to a loaded address.
0302 B6 03 dw 03B6 Routine: Read the program 0304 B5
033C 03 db 03 Type
033D 02 03 dw 0302 StartAddress
033F 05 03 dw 0305 EndAddress
0341 20 20 20 20 20 20 20 20 Nome
0349 20 20 20 20 20 20 20 20
0351 20
0352 03 4C SLO ($4C,X) Scratch area BASIC pointer
Routine: Read a bit
0354 A9 10 LDA #$10
0356 2C 0D DC BIT $DC0D Interrupt control register CIA #1
0359 F0 FB BEQ $0356 Tape I/O buffer
035B 8E 07 DD STX $DD07 Timer B #2: HI Byte
035E A9 19 LDA #$19
0360 8D 0F DD STA $DD0F Control register B of CIA #2
0363 AD 0D DD LDA $DD0D Interrupt control register CIA #2
0366 4A LSR A Count 107h=263 cycle of ~1Mhz
0367 4A LSR A
0368 60 RTS
Routine: Delay cycle
0369 A0 00 LDY #$00
036B 84 C0 STY $C0 Stop motor of tape
036D A9 0B LDA #$0B
036F 8D 11 D0 STA $D011 VIC control register
0372 CA DEX
0373 D0 FD BNE $0372 Tape I/O buffer
0375 88 DEY
0376 D0 FA BNE $0372 Tape I/O buffer
0378 78 SEI
0379 60 RTS
Routine: Read a Byte (in A e $BD)
037A A9 08 LDA #$08
037C 85 A3 STA $A3 Serial counter of bits: Flag EOI
037E 20 54 03 JSR $0354 Routine: Read a bit
0381 26 BD ROL $BD RS-232 output parity/Transient cassette
0383 EE 20 D0 INC $D020 Borde color
0386 C6 A3 DEC $A3 Serial counter of bits: Flag EOI
0388 D0 F4 BNE $037E Tape I/O buffer
038A A5 BD LDA $BD RS-232 output parity/Transient cassette
038C 60 RTS
Routine: Found synchronization
038D 20 69 03 JSR $0369 Routine: Delay cycle
0390 A9 07 LDA #$07
0392 8D 06 DD STA $DD06 Timer B #2: Lo Byte
0395 A2 01 LDX #$01 Count 107h=263 cycle of ~1Mhz
0397 20 54 03 JSR $0354 Routine: Read a bit
039A 26 BD ROL $BD RS-232 output parity/Transient cassette
039C A5 BD LDA $BD RS-232 output parity/Transient cassette
039E C9 02 CMP #$02 Synchronization byte
03A0 D0 F5 BNE $0397 Tape I/O buffer
03A2 A0 09 LDY #$09 Countdown start of sequence
03A4 20 7A 03 JSR $037A Routine: Read a Byte (in A e $BD)
03A7 C9 02 CMP #$02 Synchronization byte
03A9 F0 F9 BEQ $03A4 Tape I/O buffer
03AB C4 BD CPY $BD RS-232 output parity/Transient cassette
03AD D0 E8 BNE $0397 Tape I/O buffer
03AF 20 7A 03 JSR $037A Routine: Read a Byte (in A e $BD)
03B2 88 DEY Execute countdown
03B3 D0 F6 BNE $03AB Tape I/O buffer
03B5 60 RTS
Routine: Read the program
03B6 58 CLI
03B7 20 8D 03 JSR $038D Routine: Found synchronization (and read starting address)
03BA 85 C1 STA $C1 I/O starting address
03BC 20 7A 03 JSR $037A Routine: Read a Byte (in A e $BD) (starting address)
03BF 85 C2 STA $C2 I/O starting address
03C1 20 7A 03 JSR $037A Routine: Read a Byte (in A e $BD) (ending address)
03C4 85 2D STA $2D Pointer: BASIC starting variables
03C6 20 7A 03 JSR $037A Routine: Read a Byte (in A e $BD) (ending address)
03C9 85 2E STA $2E Pointer: BASIC starting variables
03CB 20 7A 03 JSR $037A Routine: Read a Byte (in A e $BD) (return address)
03CE 48 PHA
03CF 20 7A 03 JSR $037A Routine: Read a Byte (in A e $BD) (return address)
03D2 48 PHA
03D3 98 TYA
03D4 48 PHA
03D5 20 7A 03 JSR $037A Routine: Read a Byte (in A e $BD)
03D8 91 C1 STA ($C1),Y I/O starting address
03DA E6 C1 INC $C1 I/O starting address
03DC D0 02 BNE $03E0 Tape I/O buffer
03DE E6 C2 INC $C2 I/O starting address
03E0 A5 C1 LDA $C1 I/O starting address
03E2 C5 2D CMP $2D Pointer: BASIC starting variables
03E4 A5 C2 LDA $C2 I/O starting address
03E6 E5 2E SBC $2E Pointer: BASIC starting variables
03E8 90 EB BCC $03D5 goto read next byte
03EA E6 C0 INC $C0 Stop motor of tape
03EC 8C A0 02 STY $02A0 Contain IRQ vector during tape I/O
03EF 20 93 FC JSR $FC93 Routine: Stop motor, disable int. CIA #1
03F2 20 A0 E5 JSR $E5A0 Routine: Set VIC6567 registers and devices
03F5 40 RTI
03F6 20 59 A6 JSR $A659 BASIC ROM
03F9 4C EA A7 JMP $A7EA BASIC ROM
03FC 21
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commodore 64 | 
Tognon Stefano programs
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