Early Microprocessors in Industrial Microcomputers

Jon Elson elson at pico-systems.com
Wed Mar 9 20:20:56 CST 2016

On 03/09/2016 11:30 AM, Pete Lancashire wrote:
> Before uP's many used bit slice's I'm slowly putting together a
> Westinghouse Numa-Logic 700 and 1200 setup. (BTW anyone have parts,
> software, etc ?).
> In my opinion Modicom was the best, did not need external cooling, A/B has
> clout thus pretty much dominated. Did you know they used core at first and
> some customers demanded it since it kept its ones and zeros when the power
> went away ?
As far as I know, the 7300 never used core.  No sign of 
anything like that in the book.  They did have a big backup 
battery for the DRAM, I used a couple AH 12 V Gel Cell 
battery.  The charger for the Gel Cell ran when the control 
power was off, so it was supposed to maintain the memory 
indefinitely - except the memory power switch had a dirty 
contact and would dump the memory every couple of weeks.


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