exxos's Atari, Amiga & retro forum

Hi

I'm looking to upgrade the RAM from 512 to 1MB. On the main pcb I see what I think are 16 RAM slots free (from U46 - U61) arranged horizontally above the existing RAM chips.

You also offer a 16 chip upgrade but for main pcbs later than mine as seen here:
https://www.exxosforum.co.uk/atari/last/ram/index.htm

I don't want to modify the ST much as is required by some of the other RAM upgrades and so was wondering if I could get the RAM chips I need for here? If not does anyone know where I could get them?

Thanks.

Here's a picture of my PCB for reference.

No there isn't - apparently you can't upload images - Ohhh yes there is - when you do it properly (thanks)

Hi,
Yes the RAM chips are the same, just placed in a different location on the motherboard.
So as long as you get 16 x 41256 chips and capacitors (original were 0.22uF) it should be fine. You will also need to add the missing resistors.

ChrisA wrote: 02 May 2026 23:27
Here's a picture of my PCB for reference.


No there isn't - apparently you can't upload images

Add your image in the attachments tab and the place it inline.

16 chip ram chips, through hole.

https://www.exxosforum.co.uk/atari/store2/#0111

rubber_jonnie wrote: 03 May 2026 07:20

ChrisA wrote: 02 May 2026 23:27
Here's a picture of my PCB for reference.


No there isn't - apparently you can't upload images

Add your image in the attachments tab and the place it inline.

Thanks - I added a photo of the PCB.

olivier.jan wrote: 03 May 2026 05:51 Hi,
Yes the RAM chips are the same, just placed in a different location on the motherboard.
So as long as you get 16 x 41256 chips and capacitors (original were 0.22uF) it should be fine. You will also need to add the missing resistors.

Thanks, that's great news. I assume the "missing resistors" is detailed on the upgrade page.

Actually from the picture you posted the resistors seems to be already installed on this motherboard.

Looks like the empty chip holes have solder in them, that's going to be a pain to desolder. I recommend getting a desoldering gun. It takes away a lot of the pain of desoldering.

olivier.jan wrote: 04 May 2026 00:21 Actually from the picture you posted the resistors seems to be already installed on this motherboard.

Yeah, I thought the same.

Icky wrote: 04 May 2026 08:41 Looks like the empty chip holes have solder in them, that's going to be a pain to desolder. I recommend getting a desoldering gun. It takes away a lot of the pain of desoldering.

Thanks I already have one. It will be handy here for sure. :-)