Inside the MOD_EMUP eprom burner

Power is supplied entirely from the ISA bus, which seems almost surprising when you see how much TTL is inside the case!

Inside is a stack of two PCBs. All TTL logic, no microcontroller! Here is what you see when you take off the cover:

And here is what you see when you lift up the top board:

Here is the simple ISA card that interfaces to the thing. The only complex issue for reverse engineering this is the GAL device.