A few people have been asking about circuit bending, so I thought I’d give it a go on one of my Sega Mega Drive 2 consoles. The idea is to interfere with the video RAM signals and see what sort of strange graphical effects we can produce. Completely unnecessary, of course, but that’s half the fun!

I’m using a Mega Drive 2 that’s already been giving me some trouble, so it’s not exactly the most reliable machine to begin with. In fact, the console was having problems before I’d even started fiddling with anything. That should make for an interesting demonstration!

With Zero Wing running, I began experimenting around the VRAM connections using a length of wire. The resulting glitches were certainly interesting, although the console wasn’t always particularly happy about my interference. At one point the picture went black and white, and there were plenty of other oddities appearing on the screen.

I also gave Sonic the Hedgehog a go to see what happened with a different game. Between the graphical corruption, unexpected resets and the Mega Drive’s existing problems, there was no shortage of strange behaviour to watch.

I was steering clear of pins 20 and 40 during this experiment, which I’d identified as the power and ground connections on the chip I was working with. It wasn’t a carefully worked-out modification, and shorting the wrong connections could easily damage something. Given that this Mega Drive was already playing up before I touched it, half the challenge was working out which glitches I’d actually caused!

In the end, circuit bending produced some pretty amusing visual effects, even if there wasn’t much practical use for them. The Mega Drive was already rather temperamental, and I was beginning to wonder whether the VRAM itself might have something to do with its normal faults.

Sometimes there’s nothing better to do on a Sunday than poke around with an old game console and see what happens. Preferably one that’s already broken!