SOLID-orange

What are PLDs an why dump them?

A lot of classic arcade games use Programmable Logic Devices aka PLDs, or “PALs” and “GALs” as these chip numbers are often prefixed. Outside EPROMs that store the game data these are probably the most common devices on an Arcade PCB that stores unique code (referred to as a “fuse map”). Unlike EPROMs this code is often not preserved as it’s part of the “Glue Logic” that helps route data around the PCB; and while vital to the function of the PCB it’s often not necessary for Emulation and therefore often gets overlooked. This is unfortunate for the preservation of the PCBs themselves as if any of these devices fail, it becomes impossible to replace without the fuse map to program onto the replacement.

There is an online archive of PLD fuse maps for Arcade and other devices: https://wiki.pldarchive.co.uk And I’m hoping this write up can help you contribute to that archive.

I’ve had a few requests to put together a guide on my PCB bubble wrapping technique. There’s a lot of text here because I wanted to provide insights into why I chose this method and do it the way that I do. But if you just want to know how to wrap, scroll down and follow the pictures. I tried to make it good enough that you could follow this guide without reading any text…

The Problem

I’ve got a lot of arcade PCBs, over 500 at last count. Storage has always been an issue. How do you keep them safe and dry, dust free, and static free while also keeping them compact and a solution that works for tiny boards like a Cave CV1K all the way up to an old SNK Triple Z80 3-board stack, and something that’s not going to cause me to go broke implementing it x500?

Last week I caught a listing for a “Free non-working unknown Namco PCB”: