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NeXT
November 10th, 2008, 02:54 PM
I know what pretty much all the ISA cards I own do but not this one.

http://i11.photobucket.com/albums/a166/ballsandy/P9112113.jpg

It looks like some sort of cheap memory expansion (what look to be the ram chips are not socketed) and at the least, no system I own sees it off the bat (so there is no BIOS or anything like that on it).
Anyone here got an idea?

per
November 10th, 2008, 03:03 PM
Specsheet from Samsung Electronics

KM41256-12
General Purpose Dynamic RAM - TTL cmptbl/Page mode

Number of Words=256k
Bits Per Word=1
t(acc) Max. (S)=120n
Output Config=3-State
P(D) Max.(W) Power Dissipation=200m
Nom. Supp (V)=5.0
Package=DIP
Pins=16
Military=N
Technology=NMOS

That card has 2 banks of 256k bytes of RAM with pairity, so it must be a RAM expansion. Maybe the lower 128Kb overlaps the upper 128Kb of the system's memory, making a total of 640Kb memory in the system?

*Edit*
It also seems that the card got a Real Time Clock (The black box in the upper right courner). It also seems to be a simplified/clone of this (http://th99.dyndns.org/i/U-Z/50497.htm) board.

NeXT
November 10th, 2008, 03:40 PM
I had a feeling it was a memory board.
Hmm, I wonder what software it needs to work.

MikeS
November 10th, 2008, 04:13 PM
Almost certainly a 512K parity memory board, but I don't see any clock chip on there; maybe you're looking at the delay line?

It might not need any software; have you tried some appropriate DIP switch settings on a low memory PC/XT?

Chuck(G)
November 10th, 2008, 05:14 PM
It also seems that the card got a Real Time Clock (The black box in the upper right courner). It also seems to be a simplified/clone of this (http://th99.dyndns.org/i/U-Z/50497.htm) board.

I think that "black box" is a delay line, not a clock. Most Dallas Semi clock chips of the era were in 0.600 wide DIP packages, not the 0.300 one here.

A delay line was one way to generate the RAS-CAS delay when memory chips weren't very fast. (note the pin labeled "IN").

Given that there are no DIP switches, I suspect that this is for an early passive-backplane PC.

modem7
November 10th, 2008, 10:20 PM
And from where the fingers are, this board may now have a static-damaged RAM chip.
Everyone, please practice safe SEX (Static Electricity eXit).