Amstrad PPC512 External ISA Expansion

With HUGE thanks to Joao (Website: I recently received a PCB to build up an ISA Card expansion board for the Amstrad PPC512.

This allows you to plug up to three 8bit ISA cards into the PPC512. I built up the board with just one ISA slot to start with (There was only one available on eBay and I can’t find them for sale in the UK anywhere at the moment so have to wait for some to come from China).

My first experiment was to connect a Soundblaster sound card. This is possible thanks to the Unisound DOS driver which is a driver and config utility for Plug and Play sound card under DOS.

As you can hear in the video above, this worked perfectly. A much better gaming experience than the internal beeper 🙂

The next test was to plug in an external EGA Graphics card. Luckily the wiring for CGA is the same as EGA, so I didn’t have to change any cables. Also, the RGBtoHDMI board in my monitor already supports EGA. So all I had to do was flip a couple of DIP switches on the PPC512 to tell it to use an external video card and voila!

I now have 16 glorious colours on screen at the same time and my Lemmings are the right colour as opposed to their weird pink and cyan CGA versions.

I am really impressed with what I’m being able to get out of this 086 8Mhz PC with 512k of memory.

I now need to wait for the other ISA connectors to arrive so I can get both cards connected at once. In the meantime, I think I’m going to design a 3D printed case to hold the expansion board and the ISA cards securely in place.

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