CROMEMCO - 256K RAM
In a few short years memory boards at
Cromemco had come a long way from their initial 4K RAM board. The 256K-Z
was essentially the last RAM board the (US) company made.
It had all the things learned from the
previous boards. The 256KZ could automatically switch from contiguous memory
addressing when used with the Cromemco DPU based 68000 board to bank selected
memory when using a Z80 system. Switch settings on the board determine the
address range for the 68000 memory space. The custom PROM plugged into the
IC39 socket determines the memory banks selected in Z-80 systems. This means
that with Cromemco's dual processor D-series systems you could use either the
Z-80 or 68000 Cromix Operating System interchangeably, without changing any
settings on the 256KZ memory board. If the custom PROM was removed the
board operated in just the 68000 mode. The 256KZ was byte-addressable or
word-addresseable. During Z-80 memory operations eight bits of data are
transferred at one time, while with 68000 memory operations, 16 bits of data are
transferred at one time. In this way/ there is no speed degradation when using
the 256KZ with a 68000 board.
The manual for the board can be obtained
here.
Other Cromemco S-100
Boards
ZPU
SBC 4KRAM
16K RAM
64KZ RAM
64KZ-II
RAM
256KRAM
8KBytesaver Bytesaver-II
16KPROM
32K Bytesaver
4FDC 16FDC 64FDC
WDI WDI-II
STDC
4PIO
8PIO TU-ART
D+7A I/O
Dazzler PRI
GPIB Board
XMU
XXU
Other Boards
This page was last modified
on
01/08/2011