exxos's Atari, Amiga & retro forum

Hi all. I stumbled across this today. It's from a very old eBay auction that's long gone. I'm just a bit curious;


I'm struggling to understand how this works at all without any decode logic. Any ideas?

Looks like a ROM replacement. Perhaps for a board with a removed CPU?

I can't see anything else on there to make it work, so I'd guess it needed a wire to the ROM4 line?

I bet the underside's the fun part!

BW