General Purpose 8031 Board

Built November 1992. This page written October 24, 2004

I was building one project after another with 8031 microcontrollers, and wanted to introduce my brother Matthias to the wonders of these things, so I built him this really nice development board for Christmas.

It didn't capture his interest and the board eventually came back to me. I used it as the development platform for a couple of my own projects, most notably the MP3 jukebox head unit.

The board has an interface for the ubiquitous 44780 controlled character LCD modules, assorted inputs, high current (ULN2003) outputs, and of course the 8031's serial port brought out to a standard RS232 connector. It has a very simple firmware monitor with a download routine that can accept Intel MDS8 hex records.

This project exposes a hole in my digital archive. I simply don't have most of the files any more. So I've had to scan most of the documentation in from the only paper copy, the documentation binder I made to go with the board.

You can see a larger view of the board with or without the LCD module.

The main writeup

The hardware

Documentation files I still have

timer-ints.txt - How to do timer interrupts
memory.txt - Notes on memory allocation

Sample programs

led.asm - TIL311 7-segment LED demo: Digits with pulsating brightness
lcd.asm - LCD demo, lets you type on the LCD
clock.asm - A clock on the LCD module
cli.asm - A command line interpreter skeleton

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