AMD Geode
For a while I've been searching for a small computer with these requirements:
- Runs real mode DOS programs
- Has a somewhat antiquated CPU
- Has an Ethernet card and DOS packet driver
- Doesn't consume too much power
The use case here is to run my DOS Twitch Bot I've been developing over the years.
After the searching I found that there were a few systems that could approximate this:
- A Raspberry Pi running DOSBox-X
- Thin client machines that used VIA CPUs
- Expensive single-board computers using a Vortex86 chip
- Cheaper 86Duino boards
I eventually decided to go with option 1, a Raspberry Pi emulating DOS.
At least, until I saw an offer on eBay: a used Advantech PCM-9375F for only $50 AUD, which is over $400 less than new.
Why such a huge discount? Video output is broken. Which means you can't really do much with this machine.
I bought it on Nov 07 2021 and received it on Nov 12.
Board specifications
The PCM-9375 A3 specifications shows these points that interest me:
- AMD Geode LX800 500 MHz CPU (see the AMD Geode LX Processors Data Book for more information)
- AMD Geode CS5536 chipset (see the AMD Geode CS5536 Companion Device Data Book for more information)
- Dual RTL8139 10/100 Mbps Fast Ethernet (second requires breakout board that I have)
- 5V power supply (12V needed for optional LCD)
- CompactFlash storage
- 3 RS-232 serial interfaces (only the main serial interface is given a port)
- 8 GPIO pins
This at minimum would let me run by Internet-connected DOS bot and talk to DOS over a serial port.
I've also not had an x86 board with GPIO before, so that seems like something fun to play with.
TODO: Look at board again and validate and clarify these specifications.
TODO: Include some photos of the board.
Troubleshooting
It's a little difficult to tell what's wrong with an x86 computer without video output.
TODO: Document things I've tried and how they went.