A quick look inside the Amstrad Mega PC with the system pulled apart. The Sega Mega Drive hardware sits on a dedicated ISA card inside the PC. This is the same machine that arrived in not-so-good condition with NiCad battery corrosion on the motherboard.

I picked this one up from eBay for a pretty penny, and naturally it arrived with a few problems. The battery had leaked and damaged several tracks on the motherboard. Most of the corrosion has been cleaned away, with some additional repair work to reconnect the damaged tracks. Hans Gruber has also been helping me work through the problems.

One particularly annoying fault was the complete lack of video when the Mega Drive card wasn’t installed. As it turns out, the card is part of the switching arrangement between PC and Mega Drive modes. I’d ordered a replacement motherboard from the UK, and while its layout was slightly different, comparing the jumper arrangements helped Hans Gruber work out how to bypass the switching and get the PC side working on its own. We finally had video!

This particular Mega PC is a 386SX machine with an AMD-branded Intel compatible processor, 4 MB of RAM and an option to expand that to 16 MB. The video memory can also be expanded from 256 KB to 512 KB. Not bad for a machine that has been giving me so much grief!

The Mega Drive side is rather interesting. There is a little daughterboard behind the front panel which operates the switch between the two systems. The sound even travels through the VGA connection to the Amstrad monitor. Flicking the switch and seeing Sonic & Knuckles running on the same screen as the PC is pretty darned cool.

There are still a few things needing attention. The serial ports have suffered some damage, the power supply wiring has had problems, and the original battery has been removed to prevent any more corrosion. The hard drive parameters also need sorting out. At least the PC side is showing signs of life now, which is a considerable improvement!

I also love the enormous little cube-shaped LEDs on the front. They’re ridiculous, but in the best possible way. The monitor, on the other hand, has its own horizontal-line problem and sometimes needs a little persuasion to display properly. Yet another thing for the repair list!

I’ll get everything back together and take some more photographs of the repair work. For now, I’m just happy to have both sides of this unusual machine doing something useful. A PC and a Mega Drive in one beige box. That’s what I call technology!

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