S100 Computers

Home S-100 Boards History New Boards Software Boards For Sale
Forum Other Web Sites News Index    
Seattle Computer Products --  16K RAM Board

SCP had a number of variations of this 16K Static RAM board.  The board was in fact an evolution from their first 16K RAM board the SCP-101C that also utilized TMS 4044 RAM chips.


There was the above "Standard" board as well as a "16K Plus" board shown below.

SCP 16K Plus

There  was also something called the APEX2 board. It presumably was the "ultimate" 16K board in the series. Note the jumper for "TOP 1K DISABLE" (bottom center of board) for example, no doubt to coexist with a boot ROM on the bus. 
Its not clear to me what the other differences between these board versions were. If somebody knows please let me know.


The boards all utilized 4KX1 TMS4044 or MM5257 RAM chips.

The 16KPlus board used the Cromemco style (port 40H) bank  select feature. The board could be addressed in 4K blocks on any 4K boundary. The board could be configured via a dip switch setting to come up after power on clear with bank select mode on or off.  Software bank control was done by outputting to port 40H. Unusually, the board used "bus bars" to distribute the ground lines to the RAM chips.

teh APEX board was very similar except  the board select poart could be any one if 256 selectable ports but is could be configured only to 16K boundaries.


The manual for the 16K Standard Static RAM board can be obtained here.
The manual for the 16K Plus Static RAM board can be obtained here


Other Seattle Computer Products  S-100 Boards
8086 CPU   8086 Support Board   16K (24-101)RAM   16K (107A)RAM  16KRAM   64KRAM   Serial IO    DiskMaster


This page was last modified on 10/25/2013