I have received my GAL's both from my UK source and China now! Amazingly I've just populated my PCB with SRAM and the programmed address decoding PAL and it's working! Counts all the way back to DC.

I now need to install Zozo's EXOS with fast memory checking! Is it normal to see "ERROR" flash up to the right of the memory checking when it finishes? It only flashes up very quickly, and not every time, but I've seen this both with just internal RAM and with the expansion, so I'm assuming it's when it reaches an address which isn't RAM?

I'll build up some more boards soon and let people know when they're ready for purchase. 

Very pleased. SD card interface next... 

2.32uk installed!

Working great, all RAM tests (slow, normal, fast) are working fine and are showing 576KB of memory. Very nice job Zozo, much quicker than the normal bootup and so many more nice options!

I'm not seeing any "bytes not working" messages, 589824 bytes in system and 574766 bytes unused.  That must have just been a flash of "ERROR" I saw with the palette change, as you say Zozo.

All working well, very pleased! I had to cut the tails on the keyboard membrane to get it working, though, as the previous user had made a mess of re-inserting them the last time. Getting a bit short!! 

I could now do with getting my disk controller working so I can test some software...

Looking forward to having the SD card hard drive.

I built up and tested two units tonight. I'll get the other bits together tomorrow (header + connector), then they're ready for whoever wants them. I'll put some instructions together as well -- it's fairly simple, but can be a bit fiddly clearing out solder from existing holes.

I have Bagpuss22 and geo1977 down as interested. I'll drop you chaps a message tomorrow, anyone else let me know if you're interested and I'll get some more units built up soon.

They are £15 + P&P via PayPal (as gift) for anyone interested. Postage in the UK shouldn't be much, anyone overseas please let me know where you are and I'll find out the postage cost.

I'd quite like one (UK). Can build it up myself if that's easier for you but would need a programmed GAL and PCB of course!

B.

I'll build the boards up and test them before shipping out, as I want to be sure I don't send anything out dead! These PCB's were only 50% e-tested, and the ones which were tested (if they even were?!) don't appear to be marked. I inspect each PCB before building it up, but am not 100% confident until they're tested as spotting errors on these small traces is a little tricky.

Then I highly recommend the Advanced Test in EXOS 2.4 beta!

It'll be either broken traces or possible shorts!

Broken or short circuited address lines can result very mystic errors, for example the frst 256K shadows the other 256K. In the original tests only checked each segment alone and not discovered if one segment overwrite another.
I placed many tricks to the advanced test for discover this type errors.
(But also a basic trick in the Quick Test, it is left the segment number plus inverted segment number at the first two bytes of the segment, after tested it. And in the final phase these verfied back, if it overwrited then report as bad segment)

Yes, you are right about the address lines, Zozo, I'll be sure to test them all with 2.4!

Fatbob_gb, no problem. I have 10 pcb's to make up, I think that's 7 spoken for now, plus one for myself. I may end up getting some more pcb's made at this rate...

Here's a picture of what you'll be getting. The main expansion board, a 14x2 header to install into EXP1 and a 10 way connector with ribbon to install into EXP2.

The most awkward part of the whole job is clearing the solder from the EXP1/2 through holes on the pcb. I've never been that good with a solder sucker!