Tiny TRS-80 Model III Emulation Library

The Tiny TRS-80 Model III, made by Trevor Flowers, is a 1:6 scale model of the classic microcomputer that includes a microcontroller and a 1.69" diagonal display. See https://transmutable.com/work/electronic-tiny-trs-80-model-iii

This library provides runtime support in CircuitPython for scale accurate character and graphics rendering on the Tiny TRS-80 Model III's display as well as limited keyboard input over a USB serial connection.

The runtime uses the Kreative Korp TRS-80 Model III fonts https://www.kreativekorp.com/software/fonts/trs80/, supporting both the 64 character by 16 line and 32 character by 16 line modes.

Also included is a modified version of PyBasic https://github.com/richpl/PyBasic with added support for TRS-80 BASIC display statements and functions.

Finally, the runtime library has been ported to run over PySDL2 https://pysdl2.readthedocs.io on a regular Python installation for testing.

Read more about this work here http://www.grwster.com/projects/2024/tinymodel3/

Running on a Tiny TRS-80 Model III (CircuitPython)

Plug the Tiny TRS-80 Model III into your computer's USB port, mounting its file system

Install the fonts:

• Copy src/fonts to the top-level dir (you can remove the ttf files if you want to save space, only the pcf files will be used on the device)

Install the libraries:

• Copy the Adafruit Bitmap Font library Adafruit_CircuitPython_Bitmap_Font to the lib dir

• Copy src/lib/tinymodel3.py to the lib dir

• Copy pybasic/lib/tinymodel3_pybasic to the lib dir

Run an updated version of Trevor Flower's default code in 32 or 64 char mode:

• Copy src/default32-code.py or src/default64-code.py to code.py in the top-level dir

Run the python demos:

• Copy src/demos-code.py to code.py in the top-level dir

Run the BASIC demos:

• Copy src/*.bas to the the top-level dir

• Copy basicdemos-code.py to code.py in the top-level dir

Get a BASIC prompt:

• Copy basicprompt-code.py to code.py in the top-level dir

• Connect over the USB serial cable using this guide https://learn.adafruit.com/welcome-to-circuitpython/advanced-serial-console-on-mac-and-linux

Running on a Mac (should also work on Linux or Windows, but you're on your own)

You'll need Python 3 https://www.python.org and PySDL2 https://pysdl2.readthedocs.io installed on your computer

Run the python demos:

% cd src
% ./run.sh demos-code.py

Run the BASIC demos:

% cd src
% ./run.sh basicdemos-code.py

Run a single BASIC program:

% cd src
% ./runbas.sh demo1.bas

Get a BASIC prompt:

% cd src
% ./run.sh basicprompt-code.py

Requirements

In addition to the Adafruit CircuitPython libraries pre-installed by Trevor Flowers on the Tiny Model III, you'll need to install the Adafruit Bitmap Font library:

• Adafruit_CircuitPython_Bitmap_Font

For testing on Mac / Linux / Windows, Python 3 and PySDL2 are required:

• https://www.python.org
• https://pysdl2.readthedocs.io