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Measurement Systems & Controls - DMB6400 Dynamic RAM
The DM and DMB series of boards were quite similar. The DM did not have bank select capability, the DMB did.


The board consisted of 64K of dynamic RAM with refreshing independent of bus timing.  No wait states were required wit a 4MHZ Z80. The board was addressable in 4K increments at 4K boundaries.  The board utilized low power, fully loaded it used less than 8 watts.

This board had bank selection (Cromemco & Northstar format). One of 256 ports could be selected (40H for Cromemco, C0H for Northstar).  Up to 8 boards could be used per port.  Each 16K or RAM could be set to start at 0000H, 4000H, 8000H, or C000H for any of the banks selected by the port.  The bank memory size could be incremented from 16K to 64K in 16K increments allowing 512K bank sizes.

The manual for this board can be obtained here, the schematic here, and updates here and here.


Other Measurement Systems & Controls  S-100 Boards
DM64     DMB64


This page was last modified on 10/25/2013