Z80 PLCC to DIP

So, it turns out I had a big pile of Z80 chips, but not in a form factor that I have much use for. PLCC44. All my z80 stuff is pretty vintage and uses the z80 in DIP40 form factor. This seems fine, I’ll just make an adapter PCB. There’s just one small issue. Getting these sockets to play nice is not super easy.

I added an onboard decoupling capacitor because why not

You can see those pins get pretty close together. Let’s look more closely.

Wow. So, those are not supposed to be that close together. It turns out they work, but they are close enough that I wouldn’t stick them there if I didn’t have to. It’s lucky they worked at all, right? well, it may be more than luck. The DIP and PLCC variants of this chip probably use exactly the same die layout. That means that when you put them in a leadframe and wire bond them in, the pins will be in the same relative positions to each other. So it’s reasonable that the pins aren’t completely scrambled, I’m just glad I was able to lay them out and get it working on the first try.

Here it is working in a simple NOP generator to make sure at least that instruction works. I’m pretty happy with this project, now for the cost of a PLCC socket, a PCB, and 40 pins of that nice machine pin header I can have about 20 Z80s. I think I’m actually losing money on that with those machine pins. Oh well. The files are here if you want to use them (maybe tweak it if you have a need to put the tall spot elsewhere)

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