Anoher mystery ISA card

[NeXT]

I know what pretty much all the ISA cards I own do but not this one.

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]

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 board.

 

[NeXT]

I had a feeling it was a memory board.
Hmm, I wonder what software it needs to work.

 

[MikeS]

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)]

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 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]

And from where the fingers are, this board may now have a static-damaged RAM chip.
Everyone, please practice safe SEX (Static Electricity eXit).