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need info on 16-bit memory card IBM 61X6720

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mikey99

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Does anyone have any docs or info on this memory card ?

Its a 16 bit PC/AT memory card, two cards sandwiched together
and it looks like all the memory is on the daughter card ...
8 banks of 9 chips.

P/N's main card 61X6720
daughter card 61X6667/61X6671

I've never seen one like this before. I tested this in my PC/AT and
the memory counts to 640K indicating the card is correctly backfilling
512 up to 640 K. However the memory count doesn't go any higher
than 640 K. Maybe this type of memory card needs a driver.
All other memory cards I have for my PC/AT count all the way up
to the total memory on the card at boot time.
 

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You might get a better idea of what you've got if you separated the memory board from the main board. You might find a manufacturer's name.

My guess is that you may have a LIM card.
 
THANKS for finding that !!!!!! Now I'm thinking since this is an XMA memory card it may be normal
that the memory isn't seen (counted) at boot time. It can only be activated by loading the correct
device driver. When I go through the AT Setup disk I have to specify 0 for expanded memory or I get
a memory error when the computer reboots.
 
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mikey99 said:
When I go through the AT Setup disk I have to specify 0 for expanded memory or I get a memory error when the computer reboots.
Click to expand...
ATs do not store the amount of expanded RAM in their CMOS/RTC setup. I think the wording used by your AT Setup disk is in fact "expansion" memory, not "expanded" memory. "Expansion" memory is an early term that IBM used for RAM past the 1MB mark, i.e. what later became known as extended memory.
 
What would be the best way to test this card ? Is there some expanded memory driver I could load on
an AT to see if it recognizes the memory ?
 
mikey99 said:
Is there some expanded memory driver I could load on an AT to see if it recognizes the memory ?
Click to expand...
You need to obtain the particular expanded memory driver for your card. That is referred to in the document that RJBJR pointed to. Without that particular driver, the expanded memory on the card is not available.

The document contains, "The EMS is issued by Lotus, Intel, and Microsoft", and so we know that the interface provided by the expanded memory driver will conform to the LIM (Lotus/Intel/Microsoft) standard. It will probably be version 3.2 of the standard, and I base that on:
1. The vintage of the card.
2. Documents describing LIM version 4.0 compatibility usually include the "4.0", e.g. "LIM 4.0, EMS 4.0".
3. The document referred to by RJBJR includes, "through four 16Kb pages".

mikey99 said:
What would be the best way to test this card ?
Click to expand...
Once you have the expanded memory driver in place, diagnostic utilities such as CheckIt will report available expanded memory, and provide the means to test the expanded memory.

That isn't necessarily the best way, because IBM may have produced a software tool that tests that specific card.
 
Thanks for the info ! I downloaded that file but it appears to be for a PS/2 XMA memory card.
Any other ideas where I can get the driver for this card ?
 
I wonder if the drivers that come with some versions of DOS will work with this card......
DOS 4 and 5 have an XMA2EMS.SYS driver. There may also be some possibility that QEMM
will recognize the card. I have the DOS 5.0 diskettes somewhere, will try that driver
as soon as I can find it :)
 
Hmm, I have several versions of QEMM, 5/6/8 and all are only for 386 machines.
Does anyone know if there are any versions of QEMM that support 286 machines ?
 
mikey99 said:
Hmm, I have several versions of QEMM, 5/6/8 and all are only for 386 machines.
Does anyone know if there are any versions of QEMM that support 286 machines ?
Click to expand...
QRAM is the more-or-less equivalent for 8088/8086/80286 PCs, but I think you'd still need a suitable EMS manager as well.
 
Here is a little info from Microsoft about drivers and memory, the most interesting bit was this:
"The IBM PC-DOS version 4.0 driver XMA2EMS.SYS takes IBM XMA memory (or the emulated XMA memory created by the XMAEM.SYS driver) and uses it to emulate LIM/EMS memory."

From this page - A General Tutorial on the various forms of memory
http://support.microsoft.com/kb/37242

And here is something about XMA2EMS.SYS from IBM, seems the driver should work with a 286 and your 2MB XMA board.
http://ps-2.kev009.com:8081/pcpartnerinfo/ctstips/bb76.htm


PC-DOS 4 was released in 1988 so there is a chance of that driver working that XMA board.

I can aim you to images of that version if needed.
 
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SUCCESS !

RJBJR, thanks for the pointer to the DOS 4.0 images !
Using XMA2EMS.SYS the memory is accessible and tests okay.

I also found a copy of QRAM, might try that too over the weekend.
 

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I found QRAM on an ftp site, can't recall the url , the filename is qram202.zip

Try a Google search for qram202.zip it should be easy to find
 
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