4mb upgrade possible on this 1040 STFM?

[grinoir]

Hi all of you
It saddens me to see that my motherboard don’t provide me with an easy way to upgrade my ram to 4mb.
Is it possible in some way? How?

F0201B06-7137-4EDA-BF4F-9423062016DA.jpeg

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[exxos]

Yep. But sadly out of stock currently.

4MB_SMT.jpg

https://www.exxosforum.co.uk/atari/store2/#0020

[rubber_jonnie]

You could use one of these:https://www.exxosforum.co.uk/atari/store2/#0035 or search on eBay for a Marpet RAM/SIMM upgrade for ST.

[exxos]

You could use one of these:https://www.exxosforum.co.uk/atari/store2/#0035 or search on eBay for a Marpet RAM/SIMM upgrade for ST.

He has SMT MMU - so can't use #0035 or Marpet (yuck!) .

[rubber_jonnie]

You could use one of these:https://www.exxosforum.co.uk/atari/store2/#0035 or search on eBay for a Marpet RAM/SIMM upgrade for ST.

He has SMT MMU - so can't use #0035 or Marpet (yuck!) .

Oh yeah, well spotted and yuck indeed!!

[grinoir]

Thanks exxos,
Will it be back in Stock? If so is there a timeframe?
Is it a hard installation, should I get another computer?
I do not own a desoldering station only a tin sucker.

[exxos]

They will be in stock again but not sure when. But it is difficult to fit, so you may want to get someone to fit it for you.

Some more info here https://www.exxosforum.co.uk/atari/last/4mb/index.htm

[grinoir]

Thank you. I think that I can do that. I need this!
I will check back in your store
Thanks

[troed]

Thank you. I think that I can do that. I need this!

Desoldering the old RAM chips is a _lot_ of work. I would be hesitant to do it with just a solder sucker, esp. if you haven't done it a lot already. My first choice is a proper desoldering gun, and the second (much more risky) is a hot air station where you simply lift the ICs up when all the solder has melted. The second trick is fast, but has a non-zero risk of frying the motherboard a bit.

Installing the replacement RAM board once the chips are out and you've cleaned the holes from old solder is relatively easy even with just casual soldering experience and equipment.

[krs]

Also worth noting is that on the 80-pin SMD MMU the MAD9 pin is pin 66 instead of pin 64 as on the socketed MMU, and you have to solder the wire directly to the leg of the chip. I'm about to perform this upgrade myself but I'm waiting for a desoldering station that I ordered, because I sure as hell ain't removing 32 16-legged chips with desoldering braid and solder sucker!