rabbitc64/README.md

Rabbit Scooter — C64

A Commodore 64 port of rabbitroller, the Game & Watch style LCD mini game, written in 6502 assembly (built with the ACME assembler, using the same toolchain and layout as c64-demo).

Rabbits hop toward you on a five-lane road. Steer your scooter left and right to dodge them: a rabbit that reaches your lane is a miss, one that passes in any other lane is a point. Three misses end the round. The spawn rate and the rabbits' speed ramp up with your score, just like in the original.

Controls

Input	Action
Joystick port 2 left/right	change lane (auto-repeats while held)
Fire (or SPACE)	start / retry

How it works

• PAL frame loop synced by polling the raster beam (no interrupts), one state update per frame — title, play and game over are updvec states.
• The player is hardware sprite 0; up to seven rabbits live on sprites 1–7. Rabbits follow the road's perspective: a linear y ramp and a t² horizontal fan-out, both precomputed into tables at assembly time (tables.asm). Far rabbits use small sprite frames, near ones switch to big frames and finally to double-sized expanded sprites.
• Random lanes and speeds come from an 8-bit LFSR stirred with the free-running CIA timer.
• Sprite art sits below $1000 so the VIC never sees the character ROM shadow instead of it.

Files

File	Contents
main.asm	BASIC stub, init, frame loop, state dispatch
defs.asm	registers, constants, zero page, macros
title.asm	title screen: logo, parked scooters, demo rabbits
play.asm	gameplay: input, spawning, scoring, HUD
over.asm	game over box + retry
common.asm	shared routines: printing, road, input, RNG, rabbit positioning
tables.asm	assembly-time perspective and speed tables
sprites.asm	sprite art (scooter, 4+4 rabbit frames)

Build & run

make deps        # macOS: brew install acme vice
make build       # -> rabbit.prg
make run         # build + launch in VICE (x64sc)

The same targets are available as VS Code tasks. A test build that boots straight into gameplay: acme -DAUTOPLAY=1 -f cbm -o test.prg main.asm.