Apple II "Xdraw Xtravaganza" 128B Demo

Presented at Outline Online 2021 Demoparty (won 2nd place oldskool 128B intro)

By -=DEsIRE=-: code by deater

Should run on Apple II+/IIe (needs Applesoft in ROM)

Note that it's extremely rare for an Apple II demo to place this high at a European demoparty. It helped that newskool/oldskool were separate as really no one can compete with DOS.


Capture on an actual Apple IIe Platinum.

Sourcecode and Disk Image

You can get the disk image here: xdraw128.dsk (140k), 15 May 2021

You can get the official entry zip here: (56k), 15 May 2021

You can get the sourcecode here in the demos/outline2021/128b/ directory of my dos33fsprogs github repository:
git clone
Vote for this at Pouet

Run-through of the Effects

This code takes advantage of Apple II shapetables. This is a neat feature of the Apple II: in-ROM scaled/rotated vector drawing routines. You can point to a nul-terminated list of numbers and it is interpreted as a series of vector drawing commands.

You can DRAW the pattern at a location on the screen with SCALE and ROTation. You can also XDRAW (exclusive-or) which is handy if you want to also erase something you previously drew.

Normally you'd pain-stakingly plot out the vector you want to draw, but if you're doing size-coding you can just point to random parts of RAM/ROM and hope for the best and maybe find some interesting results.

This first result was one I accidentally made when trying to make a compact lovebyte entry. It's almost a circle, but as you can see on real hardware with aspect ratio it's more of an oval.

I also found this one by accident, it's what you get if you treat the ROM at $D004, $D104, $D204, etc, as shapetables with rotation.

This one was the basis for my 16-byte Lovebyte entry, it's a nice pattern you can find by using $F001 in ROM as your shape table.

Finally I wanted to find some other interesting patterns. I methodically searched starting from $D000 at the beginning of the Applesoft ROM. The first nice set of patterns was around $D34D for about 32 patterns or so. So this demo shows them, then does them again with rotation. In theory it will do this for 64 angles before repeating, but for time reasons the demo version is cut off after only 1 angle.

There might be further better patterns, I've only searched through about 1000 of the ROM locations and there are many more left unexplored.

Some people watching the demoparty stream enjoyed the wipe "effect" between scenes. I always find that amusing, as long-time Apple II people would recognize that as the stock "HGR" screen clearing that ends up looking like a fancy venetian-blinds thing due to Woz's bizzarre memory layout.
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