OS-9 Projects

These are programs that I wrote for the Motorola 6809 version of OS-9, with some Tandy Color Computer 3-specific extensions. Most are in assembler except for gifstar which was written in a combination of assembler and C.

I no longer have the equipment necessary to maintain these programs. In fact, in most cases I don't have the code either. Bummer. If you have a copy of one of these, please send it to me.


The closest thing to a productivity application I've ever written in 6809 assembler (3500 lines on the last printed copy that I can remember). Supported periodic repeating events, alarms, configurable warnings, priorities, execution of commands. I had to write my own date and math libraries for this thing--it truly was written from scratch. I got through the last two years of high school and first year of University keeping appointments in this program.
A sound digitizer that used the analog joystick port of the Tandy Color Computer 3 to create up to 400 kilobyte long sound samples under OS-9 Level II. The hardest part (aside from making the cable) was to figure out how to use the CPU instruction cycle counts to keep the same realtime sample rate while doing page flipping. I think I wrote this because some company or other was charging US$40 for a trivial piece of software and two resistors in a short piece of cable. I guess I had a bunch of Richard Stallman in me.
A 28K C program (the biggest I ever wrote at the time) that converts a GIF into input for a Star NX-1000C color dot matrix printer. It could produce an 8.5x11" dithered image of a GIF in about 90 minutes in the first version, and about 25 in the last version, running on an OS-9 system. My OAC physics project (last year of high school) used this program as an example of how color dithering works in real life.