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S.C. Digital -- 256K/64K Dynamic RAM Board
S.C Digital came out with this board around 1982. The board was IEEE-696 compatible working with 8 and/or 16 bit data paths on the bus.

SCD 256K DRAM

Being IEE compatible of course it could use 16 or 24bit addressing.   It could be stocked with 16K X1 or 64K X1 RAM chips.  Memory was organized in 2 blocks, each occupying 1/2 of the address space.  There was a S-100 phantom disable which could be disabled by a switch on board.  There was a switch also to select A0 or A0* as the most significant byte on the bus.  Access time was very fast, 180 nsec from SMEMR or pSYNC high. This allowed a Z80 to get to 6MHz or the 8086 family to get to 8MHz. 

There does seem to be some slight variations of this board out there. For example see below one with a single 5V regulator. It is labeled 256K-KZ the one above is 256KKE.

SCD 256K DRAM 5V

The manual for this board can be obtained here.

 

Other S.C Digital   S-100 Boards
80286 CPU Board    256K RAM    1MG RAM   32K RAM     16K RAM     Z80 CPU Board

 

This page was last modified on 06/26/2015