kleung21 wrote on 2024-02-12, 20:37:

AT&T globalyst ... proprietary ram expansion daughter card

I feel personally called out 😀

kleung21 wrote on 2024-02-12, 20:37:

When plugged in, the daughter card does sometimes show 20mb ram (4 onboard + 16 expansion) but then it crashes. Sometimes, i doesn't recognize it on boot.

intermittent so most likely bad connection

kleung21 wrote on 2024-02-12, 20:37:

I'll try to provide photos later but it uses some custom pin /connectors.

Please do, high res front and back, preferably also good quality picture of whole motherboard. Its possible we could even cook up bigger capacity replacement module.

kleung21 wrote on 2024-02-12, 20:37:

Interested in your thoughts/experence.

I could say I have some experience with AT&T globalyst custom memory expansions (look at signature) 😀

Great to have a ram expert in house.

Here are some pics of the board 16 mb ram expansion. Looks pretty good to me.

And here is the motherboard socket for the ram expansion

I have circled where the ram plugs in

From the photos looks like a couple of areas of maybe something sticky, and a few bits of debris near tracks near one of the connectors on the motherboard. Could be worth cleaning up and checking for any broken/shorted tracks.

AT&T Globalist 200S = NCR Safari 3152 = Samsung NoteMaster 486P = SAMSUNG SENS 700
https://adnoteh.ro/retrowikid/index.php/AT%26 … _Globalist_200S
16MB is theoretical max, cant tell if really max without seeing whole motherboard front and back (chipset etc) looks like 200 has very similar motherboard, PicoPower PT86C368 chipset with no available documentation 🙁 https://www.ebay.com/itm/112655868253
Nice and shiny solder on the module. First things first wiggle all connectors looking at pins, or better yet get yourself thin screwdriver/metal pick and try poking all pins under magnifying glass checking if any move. Then remove all sticker from module and do same for ram. If you have a scanner please scan this ram - gives better quality than photos 😀
Did you take care of cmos battery? they love to leak.

Thank you for the quick response. Eagle eyes. The smudges are from tape holding the cross battery wires so could have damage there. The discoloration I will see if it has bad traces

Any concerns if I use battery terminal cleaner spray on the pins/ contacts,?

The CMOS battery looked good but upon removal. Corrosion was noted at the contact terminals as electrolyte tracked along the cables