Programming without changing the EPROM

The EPROM contains all software described in the online user manual. But maybe you want to experiment yourself and don’t want to erase and reprogram an EPROM for that. With the Loader application an external device can load new data, programs and commands into the Gigatron RAM.

We prefer to use an Arduino as external device because that is most flexible and very cheap. You can use four male-to-female jumper wires to hook it up as shown below. The Arduino then acts as a bridge between your computer and the Gigatron, giving you an easy way to use its keyboard and storage.

The sketch on GitHub shows how to send data and start a simple example program, Blinky. This is a program that continuously blinks a pixel in the middle of the screen. Blinky is written directly using 16-bits vCPU instructions, as a proof of concept.

To make things even easier and fun, we’re currently also working on a GCL translator. With that in place you can type commands on your keyboard and immediately see them executed on the Gigatron. Keep following this page for updates! There will be no need for an EPROM update, because the Loader in ROM v1 makes this mode possible as well.

How it works: complete walk-through

Duration: 52m22s

You can also download the PDF slides of the presentation (15.1MB).

Emulation

Martin kindly made a nice visualizer for the Gigatron. It is a bit rough, but cool and useful. It is realtime and also does the sound and blinkenlights. It works on Linux, Mac and Windows. You will need to study the included README file to know what buttons to push and where to place ROM files.