MegaST board with strange CPU mod

[dml]

I'm looking at a MegaST board with some issues and the first thing I notice is a mod on top of the CPU.

A DIP68 socket has been soldered/piggybacked directly on top of the 68k CPU, onto the top/exposed part of the legs. The 68k itself is still soldered into the board - doesn't look like it had ever been removed.

The socket itself is empty but I guess it had some kind of adapter or booster at some point - still I'd expect a booster to need the CPU removed or pins lifted and I don't see that here. Maybe a storage adapter of some kind?

Stranger still - there's a single row of pin sockets soldered horizontally on the side of the 68k & DIP68 socket, just 7 pins. Also empty.

I'll try to upload a photo later but if anyone has an idea of what this was for, it might be a good clue for what happened to the board.

[dml]

Here... pins 12-18 were mapped to second set of pinsockets.

Screenshot 2025-06-10 at 17.45.30.png

[exxos]

Probably blitter patch someone tried to refit after adding the socket. Don't forget to repair the track on the bottom of the motherboard under thso CPU... There's loads of threads about it.

[dml]

Ok thanks, I'll look into the blitter patch then...

[exxos]

viewtopic.php?p=1340#p1340

[frank.lukas]

my Blitter Patch ...

cpusockel.jpg

zweiter_sockel.jpg

[dml]

Heh - nice. The track under the CPU is indeed cut.

So I think that part of the mod is/was definitely a blitter patch. The CPU socket itself - not sure but I think I'll remove it all, fix the track and see if I can get any life out of the board.

Will figure out if it needs a blitter patch much later as it doesn't look like removing it would stop the machine booting.

[dml]

Well that was fun.

While poking at this board I decided to try it with the PSU from my trusty old 'working' Mega4. Which didn't work.

Then I decided to try the 'working' Mega4 itself, with its own PSU, just in case. That didn't work. o_O

So I was hoping to fix my way to [+1 == 2] MegaSTs and ended up with [-2 == 0] instead.

Done for today, I think.

[exxos]

Have you played Atari today ? :P :hide:

[dml]

Have you played Atari today ? :P :hide:

I think it's the other way around!