deater78

It took a while due to the atariage backlog, but finally have an actual Myst cartridge... and no, they won't be for sale, but I've been having interesting discussions about this with various people though it seems unlikely to amount to anything. Also due to the mapper it won't work on a 2600+ but in theory it might be possible to re-write things so it would (but it would probably need at least 64k of ROM if not more though in that case though)

I just released version 2.6 and I'm going to call this finished. Seems to play fine on stella, MAME, and also on real hardware with a harmony cartridge. Here's a longplay video:

I've implemented picking up and using the red/blue pages. You can now get all four endings to the game. nearing completion of this. I need to do a lot of cycle counting to make sure everything stays in 262 scanlines, then some sizecoding as there are two more locations I want to squeeze in.

I have the clock puzzle working now. Managed to cram all the sprites for the clock face down to fit in only 80 bytes. Nearing the end here, I still want to implement the red/blue page handling enough so that all 4 endings to the game are possible.

got the fireplace puzzle going seriously low on ROM space here, at least in the small chunk of always-visible ROM on the E7 cartridge. The original implementation of this was really clever, loading values off the zero page using stack instructions and such. It was much too large though and ran out of scanlines for the logic. Simplified it a lot to only update one row of the pattern when clicked, rather than re-generating all 6 rows.

I've been working some more on this. I added a bunch more locations and it's now possible to "win" the game. However it's not finished yet as I want to add in two puzzles. Really starting to run low on room though. Here's an updated video:

each "scene" is just what's on the screen. My kernel draws a 40x48 asymmetric playfield. There is a fixed background color, but each 4-scanline high line can have its own foreground color. There is then an "overlay" made up of sprite1 that's an 8x48 strip of blocks (each overlay line can be its own color) that overlays the screen to add a bit more detail. You can also have one vertical line the same color as the pointer (this is missile0) and optionally the background on the right side of the screen can alternate with an additional color. This ends up being 448 bytes per scene (16 bytes used to describe the scene, 6*48 bytes for the playfield, 48 bytes for foreground color, 48 bytes for the overlay, 48 bytes for overlay color). I use compression which squishes things down to 256 bytes per scene (some compress a little better than that). This means I have room for roughly 60 or so scenes in the game. I'm doing this all in assembly language so I am not sure how this would map to a batari kernel.

For my game kernel the graphics for each scene take 512 bytes. For my stripped-down version of Myst there are going to be roughly 64 scenes (plus a bunch of other code for the intro and puzzles and such). I guess in theory I could maybe squeeze things down to fit in a 32k ROM. Currently I am using ZX02 compression where each level is 256 bytes or less compressed. This should allow things to fit in 16k. This does require RAM to hold the decompressed data. This is why I use the E7 ROM as it includes enough RAM to do this. Having the decompressed data in RAM has other benefits too, as for some of the effects and puzzles I patch the graphics on the fly rather than having separate copies. Doing a "full" VCS version of Myst would be a lot of work. I did do a full Apple II version with similar graphics limitations (40x48, but only 15 colors, but you have no limitations of colors per line). This involves roughly 800 scenes, in the end taking three 140k floppies, so roughly 400k or so of data (most of which is compressed).

when accessing the memory location (on Apple II we'd call this a soft-switch, not sure the right term on vcs) to swap in the RAM to the address space it indicated this with a "ram enabled" flag. When you later swapped ROM back in, the "ram enabled" flag was never turned off, which as you can imagine caused issues. All that was needed was a one-line fix to disable the RAM again after swapping the ROM back into place.

have some time to work on this project again. Plan is to get a speedrun-capable version of Myst to fit on a 16k E7 cartridge. I'd estimate it's about 75% there currently. as a side effect of this work found a bug in the E7 cartridge support in javatari today, but found a fix and sent it upstream

It took a while, but I finally got around to making an NTSC version of this. I mostly just fixed up the resolution and colors, I left the music as-is which means it plays too fast. NTSC ROM: http://deater.net/weave/vmwprod/demosplash2022/vcs_desire/vcs_desire_ntsc.bin

OK, even though this was mostly meant as a parody, I've fixed things up so now it is actually a full "game" that you can win or lose. Also added some extra scenes. I'm going to declare this done for now, although there's about 80 bytes free (on the 8k ROM) that are taunting me wanting some extra content

so I made another game of sorts, this one is based on an ancient screenshot the Homestar Runner people made that was a parody of the E.T. game but with their own character, The Cheat. You can skip the so-so title music and get into the gameplay. There's a webpage for it here: http://deater.net/weave/vmwprod/cheat/ with a link to the ROM (8k) and source code Directions: you are The Cheat. Bubs (the orange guy) in the concession stand wants 12 Cheatcakes (little yellow boxes). You can only carry 4 at a time. Find them and bring them back to him. Don't get caught by strongbad (red guy) or he will steal your cakes and send you back to your house. If you fall in a pit, use the joystick button to levitate out. Also watch out for grumblecakes (black boxes) as too many of those are bad for you.

The Lovebyte demoparty had a big Apple II presence this year, including a special message from Woz himself I had 12 entries that were all Apple II (or Apple II related) ranging in size from 8 bytes to 1k. You can see them here, with some descriptions: http://deater.net/weave/vmwprod/lovebyte_2023/ The 1k entry finished in first place. Try out the 8-byte entry yourself by running the following at at Applesoft prompt: CALL -151 B8: 2c ea 20 f4 f3 20 d8 f3 B8G

it should be relatively straightforward to do a PAL port. It will have to wait until after the NTSC version is finished though.