| Deathchase | Routines |
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1 REM (c) 1983 M.ESTCOURT / RANDOMIZE USR 23296 and a bunch of other stuff to fool the naive hacker that there's a loading system at 5B00. (There isn't, and from a single BASIC program it's technically impossible)
2 CLEAR 32767 : BORDER 0 : RANDOMIZE USR 23840 : RANDOMIZE USR 0
3 SAVE "DEATHCHASE" LINE 2
The BASIC is saved to start at line 2, which then passes control to 5D20
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| 5D20 | LD A,$00 | |||
| 5D22 | LD ($5C8D),A | Set ATTR system variable to black PAPER and INK | ||
| 5D25 | LD A,$02 | |||
| 5D27 | CALL $1601 | Open screen channel | ||
| 5D2A | CALL $0D6B | CLS | ||
| 5D2D | LD HL,$5C6B | DF-SZ | ||
| 5D30 | LD (HL),$00 | Set it to 0, so pressing BREAK will crash | ||
| 5D32 | LD A,$FF | Flag for a headerless loader | ||
| 5D34 | SCF | Set to denote a LOAD, not a VERIFY | ||
| 5D35 | LD IX,$4000 | Start of main block | ||
| 5D39 | LD DE,$3F48 | Length of main block | ||
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Load the main block. There's no valid code after this, as it is overwritten by the main code block
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| 5D3C | CALL $0556 | LD-BYTES | ||
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After the main block is loaded, control returns here
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| 5D3F | NOP | |||
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.... and a bunch of other NOPs until ....
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| 5D88 | RET M | |||
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This returns control to the BASIC subsystem at $2D2B. The game BASIC is now:
1 POKE 23659,0
2 RANDOMIZE USR 25983: GO TO 1
Control returns to the second statement in line 2 (this is set up by the routine at $6B96 which saves the game). This then calls the main entry point at $657F.
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