This is my little Commodore 64 demo for my friend Jeff's birthday on April 18th 2020.
It has been written in assembly language using the ACME Macro Assembler.
The .d64 disk image is available on the release page. There are a few ways to run it.
With the VICE C64 Emulator:
x64 -ntsc hbjf2020.d64
Press Alt-Q to quit.
With the VICE core of the Retroarch emulator frontend:
retroarch -L /usr/local/lib/libretro/vice_x64_libretro.so $(pwd)/hbjf2020.d64
(Assuming your libretro cores are stored in /usr/local/lib/libretro)
Press ESC twice to quit.
With MAME:
mame c64 -flop $(pwd)/hbjf2020.d64
With MAME the floppy won't be loaded automatically. So you'll have to type
LOAD "*",8,1
into the emulator. The c64 * character might be located somewhere else on your keyboard. On mine I have to press ] to get a *
And then be prepared to wait a loooooong time. That's entirely my fault, this demo is not optimized for size at all.
Once you get the READY prompt again, type
RUN
to start the demo.
To quit: Press the SCROLL LOCK key to reactivate your keyboard, and hit the ESC key to quit.
I have built this under Linux. It should be a similar process to build under MacOS or maybe even Windows with a few tweaks.
A makefile is included, running make should produce a usable hbjf2020.d64 file in the obj subfolder.
In addition to make you will need the following tools:
ACME is the cross assembler used, it will produce a .prg file. The makefile uses c1541 from the VICE package and builds the .d64 from that .prg.
The ./run script will build the program and start it using the VICE emulator.
Background has been created in GIMP with this Judas Priest font.
The included .xcf from GIMP has been exported to a .png file. The 64 code is generated by image2c64 :
image2c64 -f hires --raw ./background.png
That will give us two files, a monochrome bitmap in background_bitmap.raw and a color map in background_screen.raw which we will include in our code.
The sprites have been created with Spritemate, a neat online app.
Sprites were saved in mysprites.spm and Spritemate also exported a sprites.a that is immediately usable in our code.
I recorded the output from VICE using OBS and then generated an animated gif with ffmpeg:
ffmpeg -i recorded_video.mp4 -t 12 -vf "fps=30,scale=320:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" -loop 0 preview_12s.gif