NCR PC3390 motherboard/personality board

[kin]

Hi, my name is Kin and I'm new here. Just found this forum with alot of great info on old pc's.

I have recently aquired a NCR PC3390, a small AT class 286 pc.

Specs:
80286-10mhz
512kb base memory
Expanded memory, 2x 1mb
Onboard display adapter MDA/CGA/EGA mode (9pin).

Kind of propriarty ISA riser with 2 slots:
Slot 1: CPU / IO board
Slot 2: Currently using an ISA vga Trident8900 card, 15pin).

I would like to know if certain chips and cpu is upgradable and if there is some way to get to 640kb base. I can't find any service manual for this pc.

Here are some pics, hope you you can help.


2x 1MB RAM


Propriarty ISA riser


CPU N80286-10 sx400, on the right it might be reserved for 80287


Bios? Empty spots marked with "AMP". Upper left, color/monocrome switch.

 

[kin]

Wow... googlin 1 out of a million:
http://stason.org/TULARC/pc/motherb...-MODEL-3278-XXXX-PC710-3392.html#.UWMsrspNGWI

numbers don't match but it's it alright..



stuck with max 512kb... wonder what that JM1 30pin expansion slot is for.

 

[kin]

Whadda you know:

searching on NCR PC710:

http://ummr.altervista.org/images/DSCN6121.JPG

JM1 has what it looks like a base memory expansion board connected to the 30 pin socket.