Since the dawn of time, man has searched for the ideal platform to play the Infocom classic, Leather Goddesses of Phobos. Now, with the imminent introduction of the Commander X-16, that day has finally arrived. "But," you say, "there is no Z-machine available for the Commander X-16!" Well, look no further! (Actually, look further. This one is pretty terrible.)
Ziggurat is a Z-machine interpreter written from scratch in 65C02 assembly language, based on the Z-machine Standards Document version 1.1. The main impetus behind this project is as follows:
- Learning/remembering 6502 assembly
- Learning how to program for the Commander X-16 (using banked memory, VERA, etc.)
- I've just always wanted to write a Z-machine
A lot of things work at this point for version 3 games. Lots of things still to do, though:
- Split windowing code out into a separate library for easier reusability
- Move character glyph map info into the font file (since it really belongs together and it can all live in VRAM then and free up more low memory, and also can have different font files)
- Implementing opcodes for higher level games (Note: This includes actually checking the version of the game to see if the opcode is supported)
- Blorb/Quetzal file support
- Graphics mode for V6 games
- Sound?
You will need the following to build and play with Ziggurat:
- cc65 assembler
- GNU Make
- Some Z-code game files (I've been testing with the games from Activision's Classic Text Adventure Masterpieces of Infocom, but there are lots of game files out there.)
- At least release 37 of the Commander X-16 emulator
- Possibly a couple ROM patches I did at my own fork of the ROM to fix a couple CBDOS issues with reading files.
Building should be as simple as running make. I've been developing on Windows 10, and I can say that creating SD card images to test with is a pain unless you install Windows Subsystem for Linux 2 (which requires the Windows 10 2004 release). So it may be simpler to just develop/test on Linux instead.
To make a SD card test image, I use the following little script in WSL 2 Debian:
#!/bin/sh
dd if=/dev/zero of=card.img bs=1M count=1024
printf 'n\n\n\n\n\nt\nc\nw\n' | fdisk card.img
LOPNAM=`losetup -f`
sudo losetup -o 1048576 $LOPNAM card.img
sudo mkfs -t vfat $LOPNAM
sudo losetup -d $LOPNAM
sudo mount -o rw,loop,offset=$((2048*512)) card.img card
sudo cp ziggurat.cx16 card/ZIGGURAT
sudo cp dats/* card
sudo umount card
That copies the Ziggurat program and all the game files (which I keep in a subdirectory) onto a 1GB SD card image that I can use in the emulator by running ../x16emu.exe -scale 2 -sdcard D:\\x16\\ziggurat\\card.img -debug &. (The -scale 2 is because my monitor is 1440p and my eyes are old.)
The license for this code is non-existent. It's all hereby released into the public domain. Use it as you like. (Although why would you want to?)
- Daniel Hotop, for suggesting using 2bpp text modes to increase the font size