Logo Dreams Demo


1st place combined-demo at Demosplash 2021.
By -=DEsIRE=-: code by deater, music by mAZE.


A demo with some fancy graphics / music all running on top of Apple Logo // (LOGO being the hard-to-google-for turtle graphics program from the 1980s).

Video

Recorded on actual Apple IIe Platinum. Trying out a retrotink 2 for the capture this time. Still having some trouble with the sound quality.

System Requirements


More info

The idea for this first started when the Twitter AppleII Basic Bot added support for LOGO programs over the summer. I was going to try to be extra clever to load machine language payloads in LOGO (like we do with BASIC) only to find that the newest version of Apple Logo // had direct support for loading and running machine language routines.

I had existing code for playing Mockingboard music in the background that I used for last year's Applesoft Bot Demo so it was somewhat straightforward to adapt this. Logo is built on top of Apple's ProDOS operating system through so I ended up updating my dos33 command line tool to have an additional tool for manipulating prodos filesystems from the Linux command line.

This demo is not that large, about 12k of data or so, but putting the files somewhere they wouldn't interfere with the running of LOGO was tricky. The manual for Apple Logo // actually has some helpful hints on where you can load things. In the end the MUSIC player code is put in the unused file buffer space [LOGO allocates room for having 8 files open at a time] at $4C00, the actual PT3 music, graphics, and credits effect were loaded at $1000 which is the editor scratch buffer.

Fitting on disk wasn't too bad either, but I had to delete some of the help files and sample code to make room.

The MUSIC player is a version of my PT3 (VortexTracker) player for Apple II modified to use as little of the zero page as possible. This requires a Mockingboard (which has AY-3-8910 sound chips on it).

Some notes on the various parts:

Frequently Asked Questions


Sourcecode and Disk Image

You can get the disk image here: logo_demo.dsk (140k), 14 November 2021

You can get the sourcecode here in the demos/logo_demo directory of my dos33fsprogs github repository:
git clone https://github.com/deater/dos33fsprogs/
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