This project reverse engineers River Raid, a classic game for ZX Spectrum 48K published by Activision, from the original tape image using SkoolKit.
- Install SkoolKit. At least Skoolkit 8.4 is required.
- Install Pasmo. It is used to compile the disassembly and make sure that it produces exactly the same snapshot as the one made from the game image.
- Build the disassembly:
$ make tap2sna.py -f @river-raid.t2s \ --reg pc=23762 \ --reg sp=65344 \ https://zxaaa.net/DENIED/River%20Raid%20%281984%29%28Activision%29.tzx \ river-raid.pristine.z80 Downloading https://zxaaa.net/DENIED/River%20Raid%20%281984%29%28Activision%29.tzx Writing river-raid.pristine.z80 sna2skool.py --hex river-raid.pristine.z80 --ctl river-raid.ctl > river-raid.skool Using control file: river-raid.ctl skool2asm.py --create-labels -f 1 river-raid.skool > river-raid.asm skool2bin.py --ofix river-raid.skool - | bin2sna.py --border 0 --org 16384 --start 23762 --stack 65344 - river-raid.fixed.z80 Parsed river-raid.skool (0.96s) Wrote ASM to stdout (0.24s) pasmo river-raid.asm river-raid.bin Wrote stdout: start=16384, end=63488, size=47104 bin2sna.py --border 0 --org 16384 --start 23762 --stack 65344 river-raid.bin diff -u river-raid.fixed.z80 river-raid.z80
The resulting river-raid.z80 will contain the game image with all the fixes applied (mostly sprites and few assembly instructions). The river-raid.asm file will contain the disassembly.