Another Egyptian Enterprise 64

[rubber_jonnie]

You will need to put EXDOS either in the ROM/RAM slot on the external PCB or in a cartridge.

I used a couple of 60 way edge connectors, cut the ends off both then cut down one to be 6 way and glued and melted it onto the 60 way. I used a razor saw to cut and then filed and sanded so that the extension piece had the correct 2.55mm spacing.


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Wondering if it would be worth trying a ROM cart for the EXDOS ROM but I'll try burning another ROM for the FDD card first. Better go find and erase some.

Odd that it booted once and not since and that the :help command doesn't show the EXDOS ROM present.

Interesting you used two 60 pin connectors. Still find it weird that you can get 60 pin, 72 pin and seemingly nothing in-between.

[rubber_jonnie]

OK, so I dropped in a new ROM, it still won't boot but I managed to get to into BASIC and run :help and the ROM was present, but the connections are so iffy that if I so much as sneeze everything crashes...

In the office tomorrow so won't get a chance to look at it and hoping that the replacement RAM IC will arrive as I want that sorted so I can button everything up and work on the FDD card as a separate item. The case being buttoned up might give me slightly better alignment. Who knows.

So I can see the ROM intermittently, I have booted from the Gotek once, so I'm thinking it's kinda working just not reliable. I'll see about getting another edge connector to see if I can do a better job of trimming it as I think that's part of the issue.

Reminds me of the ZX81 wobbly RAM pack situation.

[rubber_jonnie]

Well dammit...

The replacement RAM IC arrived yesterday and I still have issues with it crashing when installed in the machine. I'm pretty confident it isn't the RAM now, which just leaves the GAL or the connections to the board.

I've reflowed all the connections on the RAM expansion and on the mainboard just in case, but the answer is still nope.

If the FDD controller wasn't so damn flakey I'd try the RAM in that too, just to see how it fares. Maybe I should just do that anyway...

I'm almost tempted to tin the edge connector on the mainboard to see if that improves contact at all. I remember with my original ZX81 RAM pack being awful and I soldered it directly to the edge connector. That didn't wobble again...

Would help if I had some ROM cartridge PCBs so I could try putting the FDD ROM elsewhere.

If I had any hair left I'd pull it out.

[stephen_usher]

The main PCB edge connectors are high quality, gold plated ones, so hard to tarnish

[rubber_jonnie]

The main PCB edge connectors are high quality, gold plated ones, so hard to tarnish

Yeah, I'm not going to be tinning them, I've cleaned them multiple times and I don't think they are the issue.

I think its something else but what is another matter.

[PhilC]

The main PCB edge connectors are high quality, gold plated ones, so hard to tarnish

Yeah, I'm not going to be tinning them, I've cleaned them multiple times and I don't think they are the issue.

I think its something else but what is another matter.

I'll try give my board a go and will let you know how I get on.

[stephen_usher]

I take it that you've checked that the on-board buck regulator is outputting a stable 5V?

I didn't want to chance it so installed one I knew worked.