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Cromemco XXU Board
Clearly one powerful S-100 board.  It contains a Motorola 68020 running at 16 MHz.  The board came out in 1986. The S-100 bus had come a long way in 10 years!

XXU Board

Cromemco's XXU processor board provided a bold leap in microcomputer processing power, exceeding previously offered microcomputer speed by a factor of three or more. By integrating a 16.7 MHz MC68020 microprocessor, a 16.7 MHz MC68881 floating-point coprocessor and a 16 KByte two-set associative data and instruction cache onto one S-1Q0/IEEE-69 6 card, the XXU offered performance heretofore unavailable in a general purpose microcomputer at the time. Using Cromemco's 2048KZ memory boards, which featured Cromemco's exclusive double-word transfer extension to the S-100/IEEE-696 bus, data can be moved on the bus at rates as fast as 8.33 megabytes per second. This was more than double the transfer rate of previous Cromemco products.

The XXU also provided a real-time clock/calendar with battery backup and a diagnostic/boot ROM. The clock had an accuracy adjustable to within seconds per month. The combination of battery backup and high degree of accuracy eliminated the tedium of entering time and date every time the system was booted. The diagnostic/boot ROM made it possible to test the basic system hardware prior to booting. This enabled configuration or hardware problems to be detected and signaled to the user quickly.
The manual (no schematic) for this 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   DPU
4PIO   8PIO   TU-ART  D+7A I/O   Dazzler  PRI   GPIB Board   XMU  XXU  Other Boards


This page was last modified on 10/25/2013