ballz
9f086c3a4f
Draws a score bar across the top 8 rows of the multicolor bitmap at $E000-$E13F (320 bytes), with HARE on the far left, SCOOT on the far right, and 5 pips for each player between them. A pip is 8x8 pixels (2 cells wide x 1 cell tall = 16 bitmap bytes): filled = 1-pixel white border around a 6x6 black block; empty = an 8x8 white square (the border alone). Pips are packed 2 cells each with no gap, so adjacent pip borders merge into a 2-px white vertical divider. Labels use a hand-built 4x8 font (1 byte per row, top 4 bits = 4 pixels) for the 8 chars H/A/R/E/S/C/O/T (64 bytes total). Each font row is expanded 1bpp -> 2bpp via a 16-byte lookup table (expand4): each '1' becomes '11' (white, from color RAM), each '0' becomes '00' (background black, from $D021). score_render() also rewrites the top 40 cells' attributes (screen memory = 0, color RAM = 1) so the score bar's palette is exactly 2 colors. Scores are clamped to 0..5 on render to defend against double-tap bugs in Phase 4.
nyuller
A C64 programming project using Oscar64
as the cross-compiler. Oscar64 is checked in as a git submodule under
./oscar64/.
Layout
.
├── oscar64/ # Oscar64 cross-compiler (git submodule)
├── docs/c64/ # Low-level C64 reference (memory map, VIC, CIA, SID, …)
├── src/ # Your C code
│ ├── helloworld.c
│ └── build.sh # Compile + run helper
├── OSCAR64.md # Notes on the Oscar64 compiler internals
└── PROG_C64.md # Notes on programming the C64 hardware
First-time setup
# 1. Clone with submodules:
git clone --recurse-submodules <this-repo-url>
# Or, if you already cloned without --recurse-submodules:
git submodule update --init --recursive
Building
cd src
./build.sh # compile helloworld.c → src/build/helloworld.prg
./build.sh -e # run in oscar64's built-in emulator (headless, fast)
./build.sh -v # run in VICE x64 (interactive, needs a real display)
./build.sh -V # run in VICE x64sc (interactive, cycle-exact)
./build.sh -c # just compile
build.sh will build the oscar64 compiler automatically the first time
(it runs make -C make compiler inside ./oscar64/ if
./oscar64/bin/oscar64 doesn't exist yet).
Default test tool is the oscar64 built-in emulator (-e): it
runs headless, needs no ROMs, no display, and is fast. Every Verify
step in tasks.md uses this.
VICE 3.9 is installed at /usr/bin/ (x64, x64sc, x128,
xvic, xpet) and is available via -v / -V. It is a GUI
emulator and needs a real X11 / Wayland display to render — it
won't produce useful screenshots in this headless environment.
Use it from a real terminal session for interactive play-testing
and cycle-exact validation of raster IRQ and SID timing; don't
expect to script it.
Documentation
PROG_C64.md— how the C64 hardware actually works, from a low-level programming perspective. Start here if you want to understand what's going on under the hood.OSCAR64.md— how the Oscar64 compiler works internally, plus a C64- specific section on how to use it well (memory model, bank switching, raster IRQs, common mistakes).docs/c64/— downloaded reference material: the full Commodore 64 Programmer's Reference Guide text, Christian Bauer's canonical VIC-II paper, and per-chip reference notes.