Apple II Videlectrix Coach Z Collection

This is a collection of short games from the Homestarrunner universe collected on an Apple II floppy disk.

Video capture on actual Apple IIe Platinum (note, the audio sync is a bit off, I need to mess with OBS to figure out why it's happening):

Credits

Code: Vince `deater` Weaver
Fast disk code: qkumba
Audio code: Oliver Schmidt
ZX02 decompression code: DMSC

Screenshots / Explanations

Duck Pond (incomplete)

A Duck Pond simulator first shown in SBEMAIL Early buggy version had a fun bug, see video. Lo-res.

Rooftop (incomplete)

Obscure

Strongbadzone

A port of the Videlectrix game StrongBadZone. It's a vector-style game from strong bad e-mail "Video Games".

Like the flash version, this version is sprite based. There were a lot of challenges getting this working on the Apple II. It's nearly impossible to play audio and do anything else at the same time. Moving giant sprites around (in software, no hardware sprites on the Apple II) is really slow. Having the two alternate backgrounds and re-drawing them is slow too. We use page flipping to smooth things out and that takes up 16k of RAM.

Should play on most Apple II models. You'll need 64k of RAM to get the audio, otherwise 48k is enough.http://www.hrwiki.org/wiki/StrongBadZone

Cliff Climb (incomplete)

Minigame from Peasant's Quest

Target (incomplete)

Minigame from Peasant's Quest

Breakdancing Rat

From SBEMAIL 159. You can see more on this one at its own page

Disk Image

You can get the disk image here. sb.dsk v1.1 (140k) 16 June 2023

Play in your Browser

That might be possible at the Internet Archive

Mini-faq

Q. Are these games hard to reverse-engineer?

A. It turns out these games look more complex than they are. (From what I gather they were turned out on very short notice back in the day).

I thought for Duck Pond I'd have to implement a complex duck-AI, but the actual game they just have a set path. Same for Strongbadzone, I thought I might have to implement actual 3d-scaling code but the 3d movement is actually all just 2d.
Q. Are you doing any special tricks on the title screen?

A. I was trying to write a fast full-screen vertical HGR scroll. It's so difficult to do this and I wasn't really willing to unroll things 192*40 times. In the end I cheated and we are just scrolling the logo which is faster. It's a bit glitchy because using page flipping would make it a lot more complex.
Q. Are you doing any special tricks in StrongBadZone?

A. The title is doing some fun things to get the color-change logo. You get the nice little jiggle effect too due to the way the Apple II does color.

The large sprites are a huge pain to do quickly. I made some sprite routines that are optimized to only work with orange/blue sprites. It even allows for some transparency using the two different shades of black. I also cheat and you can't put sprites at arbitrary X locations, but rather at multiples of 3.5 as that's so much easier and faster. It does have code to allow bigger than 256 byte sprites as well as properly shifting the colors when starting on odd locations. All of this slows things down.

The last somewhat difficult stretch was making it all fit in RAM. We are using page-flipping so that uses 16k for 2 pages of HI-RES. The language card is used for the sound samples. The area between $1000-$2000 is used for disk routines. I stashed the hi-res lookup tables in the text pages. We have two backgrounds, each is 8k (at $8000 and $A000). So essentially there's only 8k left for program/data, but the executable is 16k. What to do? Well in the end things like the title screen and compressed data are loaded to PAGE2 and then we carefully move things around so that the final running code can live in the 8k that's left.

Developer Log

16 June 2023 (v1.1)
People asked for the "Back Off" easter egg. Took longer than it should have but got it going, though it exits the game (there's not really space to fit it with the main game, so it's loaded separately from disk). I considered having it be the winning condition, but that would be different from the flash version, so for now press "O" to activate it.

11 June 2023 (v1.0)
Finally have Strongbadzone fully playable. Framerate isn't as great as I'd hoped, maybe I can work on that more later. Was quite the challenge with large sprites, speaker sound, and finding room for everything including two hi-res pages.

5 June 2023
For some reason instead of finishing the duck pond code instead got bogged down implementing strongbadzone which I originally was only going to have a screenshot for but instead now it's going to end up being mostly playable. It looks suprispingly nice despite the lack of actual vector screen, the low-resolution, and the pain of trying to do everyting in orange hi-res mode. (on apple II hi-res it's only 140x192 to begin with, but having a single non-white color you have to be careful about which column you draw the lines).

31 May 2023
Put together the title screen. Getting hi-res scrolling going was a pain, cheated in the end to get a faster frame-rate without having to completely unroll things. Using this as an excuse to practice writing hi-res code.

3 May 2023
Got side-tracked and ended up doing the breakdancing rat thing instead. 13 March 2023
Not sure where this whole idea came from. Originally came across the Duckpond game and thought it would fit well in Apple II lo-res. Posted an out-take video and it was surprisingly popular.