I agree with the comments made about manufacturers not wanting a lot of
amateur device programmers about.

The problem seems to be one of their own making, i.e. a proliferation of
programming methods. You don't get the same problems putting data into RAM
chips, and EPROM programming algorithms are reasonably well documented.

Elektor did a GAL programmer that did a few types of 16V8 and 20V8.
It's 100x160 Eurocard, but the stupid placement of the LPT connector
means it can't slide into any Eurorack.
It has an on-board PSU (groan)
The I/O is done by a few cheap 4094 shift registers (minimises PCB tracks).
I built it, and bought the Elektor software disk (#15) - total cost c. #50
They then published a kludge board for 22V10s.
And wanted me to buy another disk (#15!)
They passed on my request for the Pascal source code to the author,
but I guess he is in the same position as the GAL maufacturers.

I made it when I had spare time and no job.
I then found a job and have no spare time for hobby electronics.
So it's just filling my junk box.

>From industrial experience, I found 22V10s are much more available
as producers feel less demand for smaller chips. Even if the logic
could fit in a 16V8, I'd layout the PCB for a 22V10 because someone
always asks for more at some stupid late stage in the design!

Try the Lattice chips. They're meant to be in-site programmable,
so they have to be quite open about programming so that people
can get their production jigs to program them.

Why not make a general-purpose parallel I/O port and PSU outlet.
With a standard connector like the Arcom Control Systems
signal conditioning bus connector (50-way IDC). Or opto-22.

Then you'd have a far more useful gadget which you could make
separate plug-in boards for:
- GAL programming
- EPROM programming
- Flash ROM programming
- I2C bus EEPROMs
- Smart cards
- PIC chips
- any thing you have yet to think of.
You'd also be able to use any of Arcom's off-the shelf
signal conditioning boards for opto-isolated switching of mains,
relays, etc. Why re-invent the wheel?

TTFN, KH