AT-RAMBANK on IBM 5170 AT

[labspencer]

Hi

hope someone can help me if they've had any experience with the DFI AT-Rambank 2MB expansion memory board



this pic is from minuszerordegrees.net but mine is identical rev 7 mode. maybe foolishly I bought 2 boards untested off the bay recently to get setup on an IBM 5170 AT motherboard I have. This motherboard with 512k works fine and tests out ok. the motherboard revision seems to be the 3rd and final one, at least it has 80286-8 mhz cpu and 16mhz clock, and latest IBM bios roms, although strangely it does have the u131 shunt block which is supposed to be hardwired and it doesn't have the usual serial number.

anyhow here's my problem, both the AT-Rambank boards refuse to work and stop the computer booting up, the power supply starts up but nothing appears on the screen, probably no video signal as the monitor stays in standby, not even the usual Ram post count to 512k, it just hangs. I've read through the manual and believe I've got the settings right, checked out all the ram individually (stripped it down to just Bank 0), tried different slots but no joy

Does anyone know if this board is compatible with the later 5170 motherboard, I have searched this forum and read some posts from members who have got it working with earlier motherboards but so far nothing i can find on later one. If it is known to be compatible could anyone suggest a remedy I could take, how about suspect capacitors on the board, they all look ok but I know from rebuilding a 5160 they can prevent things working as they should? I don't want to start hacking at it if it ain't going to work.

any help/info/suggestion appreciated, otherwise these boards will be back on the bay

thanks

 

[mikey99]

Is your card populated with ram chips ? I think you need at least 512K on the card.
AND you need to set the cards starting memory address to 512K

Looking at the manual, if you select to backfill the AT conventional memory to 640K,
you basically lose the rest of the memory in that bank.

 

[Syclops]

That image is from a listing I had on eBay that I sold years and years ago. LOL

I owned that exact card since it was brand new back in the late 1980's.

The picture was taken on my Pool Table, you can see the Green Felt in the background of the image.

 

[modem7]

... although strangely it does have the u131 shunt block which is supposed to be hardwired ...

An upgraded motherboard ?
Does your motherboard have two or four rows of sockets for RAM chips.

Does anyone know if this board is compatible with the later 5170 motherboard ...

I have one of these cards.
It too is the REV 7 version (printed on it is "ATRAMBANK REV 7").
All four banks populated with 41256-15 chips.
Referring to the user manual, I found that the AT-RAMBANK's switches were set to start the card's RAM at the 1 MB address.
I pulled out a 5170 type 3 motherboard (i.e. 8 MHz) out of storage, plugged in a video card and the AT-RAMBANK.

At power-on of the motherboard, I saw the RAM figure count up to 2560 KB ("02560 KB OK"), which was as expected (512 base on motherboard + 2048 extended on AT-RAMBANK).

What happens if you try that simple single-RAM-card configuration ?

Just in case, the switch settings for a start at the 1 MB address are shown at [here].

 

[labspencer]

Hi thanks for your replies

An upgraded motherboard ?
Does your motherboard have two or four rows of sockets for RAM chips.

It has two rows rows of sockets for Ram chips


I have one of these cards.
It too is the REV 7 version (printed on it is "ATRAMBANK REV 7").
All four banks populated with 41256-15 chips.
Referring to the user manual, I found that the AT-RAMBANK's switches were set to start the card's RAM at the 1 MB address.
I pulled out a 5170 type 3 motherboard (i.e. 8 MHz) out of storage, plugged in a video card and the AT-RAMBANK.

At power-on of the motherboard, I saw the RAM figure count up to 2560 KB ("02560 KB OK"), which was as expected (512 base on motherboard + 2048 extended on AT-RAMBANK).

What happens if you try that simple single-RAM-card configuration ?

Just in case, the switch settings for a start at the 1 MB address are shown at [here].

I tried again with your suggestions and one of the boards came to life hurray, I thought I had tried all the possible settings but obviously not. thanks again for your help.

cheers

labspencer