5170 Good Stuff

[Tim Knight]

While vainly trying to install a Kingston ATaboard with 2 megs in my PC/AT, I
kept getting a 601 floppy drive error each time I enabled the memory, so I went
looking for a Boca board in my bottomless pit of ISA cards. I stumbled across
the following card (and know not from whence it came):

16-bit long card FCC ID ANO9SA 55X3543 (ASM30F5368) (EC A89955)

This is an IBM card with a 65X5770 chip under an aluminum cover. It has 25DF
parallel port and a 9DM serial port receptacles, and the parallel port is
working. It also has 12 - 30 pin SIMMs slots all occupied with 1 meg SIMMs.
The great thing is that when I plugged it in, it backfilled from 512 to 640k
memory, and topped out at 12.8 meg. Works like a champ without me fumbling with
anything.

It also has a block of 8 dip switches in the upper right corner. Ther are also
those switch blocks that look like fuses in the lower right which I think may
be used to set the addresses for the ports (?).

Does anyone know anything about this card except the obvious, of course, like
where to find the dip switch settings?

Tim K

[Rick Ekblaw]

In <20020319141823...@mb-mh.aol.com>, ferr...@aol.com (Tim Knight) writes:
>Does anyone know anything about this card except the obvious, of course, like
>where to find the dip switch settings?

Sure... what you have is an IBM Multifunction Memory Expansion Adapter --
I've still got one in the original box around here (rummage, rummage) - part
number 74X8640. The little note inside the box says, "The Multifunction Memory
Expansion Adapter (P/N - 74X8640) is identical to the Enhanced Memory Expansion
Adapter (P/N - 74X8635) except that the Multifunction Memory Expansion Adapter
does not include the Above Disc EMS Emulation Software. Above Disc is a
Trademark of the Tele-West Company." The Guide to Operations book is part
number 74X7715, form number G570-2237-03. One moment while I remove the
shrink wrap -- the adapter can be populated with 256KB, 512KB or 1MB SIMMs.
According to the "rules", you can mix 256KB and 512KB SIMMs, but if you use 1MB
SIMMs, you can't mix them with the others. The rules also say that if you do mix
module sizes, the 256KB SIMMs must be installed in the top two pairs of sockets
(J1 through J4). Switches 1-5 set the starting address of the extended memory,
as a binary number of 512KB blocks using inverse logic -- for example, the
factory-shipped state of switches 1-5 is ON ON ON OFF ON, which is binary 11101,
then invert it to 00010, which is 2, then multiply by 512KB and you get a starting
memory address of 1MB. Since the first (or only) extended memory adapter
should have a 1MB starting address, this is reasonable. Switches 6 and 7 determine
the amount of base memory to backfill:

6 7 Amount of Base Memory before installing the adapter Amount of backfill
ON OFF 256KB 384KB
OFF ON 512KB 128KB
OFF OFF 640KB 0KB

Switch 8 is the I/O port enable/disable switch (ON for enable, OFF for disable).
The 8-pin DIP jumpers should be silk-screen labeled on the adapter -- the Async
section jumper is the farthest from the D-shell connectors, the Parallel section
jumper is closest to the D-shell connectors. If the connected pair of pins is on
the D-shell connector end/side, that I/O port gets the primary address
assignment (COM1 - 3F8 or LPT1 - 378). If the connected pair of pins is away from
the D-shell connector end/side, that I/O port gets the secondary address
assignment (COM2 - 2F8 or LPT2 - 278).

Rick Ekblaw

[Tim Knight]

Rick........

Many many thanks. I printed out your reply to use as a manual. And I thought
absolutely nobody would answer my question.....glad it ain't Monday.

Thanks again.......

Tim K

[Gfretwell]

This is the place to find answers about arcane IBM cards. I had one of those in
my AT too. BTW if you ever want to get rid of those SIMMs the guys with cached
SCSI cards will beat a path to your door.

[David L. Beem]

"Gfretwell",

> BTW if you ever want to get rid of those SIMMs the guys
> with cached SCSI cards will beat a path to your door.

Or those (like me) that want them for their Model 25 286s & 30 286s.
David
Da...@gilanet.com

[Tim Knight]

I just took a peek at those SIMMs, and they look like the garden variety to me.
They are of different manufacturers (made in Maylasia or Japan), but are all
1-meg and have 9 chips. I probably have a box full of them.

Anyway, I installed WIN/286 this morning and it was a hoot! It boots,
recognizes all the drives and networks to this machine without a hitch. Damn,
life don't get no better than this!!!!!!

[William Walsh]

Well, the infamous Farmwagon has their news stuff clowned up, so here
I am via google.

> I just took a peek at those SIMMs, and they look like the garden variety to >me.

They aren't quite "garden variety". The IBM 9 chip SIMMs look just
like other 9 chip SIMMs, but have the PD bits and special parity
wiring (is that the difference?) done. I have two SIMMs that look
exactly alike and were made by a third party. One is from an IBM MCA
286 RAM expansion board, the other from a big box of 30 pin RAM I
bought a long time ago.

[Tim Knight]

William.....

Is there an "easy" way to identify the ones that will work other than plugging
them in one at a time?

[William Walsh]

Well, the IBM chips (or chips wired for IBM use) will have their PD bits set
on certain pins. A look at Alfred Arnold's site for the 30 pin 1MB SIMM hack
should show those pinouts and probably how to test them, but I don't have
the URL handy.