Hi.

I am building memory boards at this very moment, and the first 35 will ship over the next week or so. The remainder have been delayed by the PCB company cocking it up again, producing the 15 outstanding boards (delayed by a previous cockup) as 1.6mm thick rather than the correct 0.8mm. So they have to redo them, which will take another one to two weeks.

pca

Are you hand soldering them? Or having it done by the board company? Or using a toaster oven?

Inquiring minds want to know!

Cheers

Hand built with love and care. Also solder and flux. And a soldering iron.

I was going to get them made by an outside company, but for various reasons this didn't happen this time around. Each one takes about 20 minutes to do, so I'm aiming for about 8 per day so as not to interfere with my other work.

pca

Yes, the board I have here looks much easier to install than I had thought. The throughholes (for soldering in) are HUGE, making them really easy to line up and get a moderate size soldering tip inside of.

Cheers

Thanks - one of the guys at work will then be able to help me.

Will these boards be shipped directly to the installer of our choice if we specified one durring our order? Might be easier on you to send a bunch to the same place all at once. Thanks, I'm looking forward to it.

Heh.. So I'm sitting down here tonight to solder on the RAM chips for my own memory board (from PCA), and.. which way 'round do the chips go?

???????????

Cheers

Wasn't there an Installation Guide in .pdf being talked about?

I think so, but it probably doesn't exist yet. And I'm actually below that level here.. I get to solder on my own RAM chips. Most of the boards come with the chips already on, courtesy of Patrick.

Anyway, I've put 48MB onto my board, at the rate of about one chip every 20 minutes (as opposed to 64MB every 20 minutes by you know who. Now to doctor it into one of the Mk2a's kicking around here..

Cheers

I would love to learn to solder but am not brave enough to take the chances learning on my empeg and memory

Now the big question..

I've populated only 48MB on my memory board, and would like to (continue to) use the existing 16MB of Mk2a memory as bank-0.

Any reason why this should not work (I expect it to, just haven't got that far yet).

And what are those dip switches for again?

Cheers

Again answering my own questions:

PCA wrote:

Quote:
The board adds 4 identical banks of 16MB, and duplicates the bank0 set currently present on a MK2A. Obviously, this isn't going to work all that well. The idea is that each bank can be disabled by means of a switch on the memory board, so in the case of a MK2A you would turn off the first bank. This would still give you 64M, as the original memory would be used.

And elsewhere I found that RA3 needs to be jumpered over from the main board to enable the final 16MB (to 64MB). The other RA{0,1,2} lines appear to already be present from the test pads.

Now to hook it up, with photos along the way..

Okay, I attached the board, got it partially working, fiddled with it for hours, and have now removed it again. Removal was suprisingly easy!

It seems trickier than first thought, to get good connections between the memory board and the main board.

Time for attempt number two.

Cheers

Have any pics of the memory board attached to the main board?

Yes, I have pics.. I'll put them up later, once I get this thing working.

I've soldered it back on again now, but bank2 is failing..

-ml

Okay, I have 48MB total RAM out of a possible 64MB in my Mk2a.

Here is my story, with photos.

Cheers

My initial attempt at soldering on the memory expansion went well enough, but was a complete failure in the end. The problem was all of those pre-soldered pads that exist on the mainboard. I was clever enough to desolder many of them (with copper braid + flux) beforehand, but not all of them.

It is necessary to desolder all of the pads (on the main board) that will lie underneath the memory expansion board, as otherwise they will cause a gap between the two boards, preventing good signal connections later on.

Absolutely critical, and just enough fuss to turn an easy installation job into one that requires considerably more care and skill than imagined earlier.

Soldering on the expansion board is dead simple by comparism.

EDIT: So, I had to remove the installed memory board and start over. Fortunately, this proved MUCH easier than it looked. I just used a nice solder-sucker device to desolder all of the through-holes, and the board slipped off with no fuss. What a shocker!

After that, I spent an hour removing all of the solder from all of the pads on the main board that would fall anywhere beneath the expansion board. Except I missed a couple in the top right (photos).. but they didn't matter too much in the end. This rework made a huge difference, as the player then instantly reported 48MB working RAM.

The remaining 16MB is not working yet (well, half of it is..), but you'll have to tour the photo link above to see why..

Cheers

It looks like for a 32meg upgrade, it'd be easier/cheaper just to stack them. For 64meg, I'm sure this is a better solution.

Well, for +32MB or +48MB (or any Mk2 upgrade), these boards are rather good -- Patrick is selling them pre-populated, so finishing them off is just a matter of desolding the mainboard pads and then attaching the new board + the RAS3 line.

But yes, for a +16MB upgrade, just stacking the chips was easier for me.

Cheers

For me soldering the RAS line was the biggest PITA. Everything else was quite straightforward.

Awesome install pics, Mark. But, how can there be "ZERO gap between the two boards"? Won't there be shorts between traces and solder? I'm comfortable using computer hardware, but I'm always nervous about components touching.

<edit>Oh, and what kind of dock is that? Hm......

Still worrying about that one - I have my stacked RAM, but no RAS line, as I buggered up the soldering once and too scared to try again. I am hoping to bribe someone with a steady hand at Amersfoort to finish the job for me.

Lots of flux (LOTS OF FLUX), a microscopic blob of solder on the iron, and the briefest of touches against the wire/pin.

Absolutely - I actually found an old chip to practice on, and I had no problem with soldering at the RAM end (after reading your and Genixia's comments about Lots Of Flux ) but can I get a connection to pin 124 on the StrongARM without touching 123 or 125?

Can I 'eck as like! Even with the smallest soldering iron and bit I could find, and a helping hands tool, and a magnifying glass. I just can't seem to get a small enough blob of solder.

So I have bought a bottle of Highland Park whisky specifically as a reward for someone who has the skill and 5 minutes of their time...they won't get the whisky until afterwards, obviously.

I was rather naughty in the end and simply lifted the pin off the board, soldered it and encased it in snot (rubbery silicone glue stuff).