River Raid Disassembly

This project reverse engineers River Raid, a classic game for ZX Spectrum 48K published by Activision, from the original tape image using SkoolKit.

Building the Disassembly

1. Install SkoolKit. At least Skoolkit 8.4 is required.
2. 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.
3. 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.