Hi and what are these?

Jon Elson elson at pico-systems.com
Fri Apr 24 11:20:45 CDT 2015

On 04/24/2015 03:01 AM, Eric Smith wrote:
> On Thu, Apr 23, 2015 at 8:51 PM, Jon Elson <elson at pico-systems.com> wrote:
>> Multibus extender boards.
> Not Multibus.  Multibus P1 is 43x2,at 156 mil pitch, like the larger
> board shown, but P2 is 30x2 at 100 mil pitch, while the smaller board
> shown is 24x2 at 156 mil pitch.
> An extender made for Multibus normally includes both as one board,
> with two card edges and two receptacles, though it is possible to use
> two separate extenders, or just the 43x2 if the board doesn't need P2,
> for instance, if it doesn't have more than 20 address lines.
Yes, but many multibus systems did not use the P2 connector 
as a BUS, but as a way to bring
serial and parallel I/O out from specific slots.  There were 
some later systems like SGI IRIS
that used the P2 as a bus to extend the datapath to 32 
bits.  But, for generic multibus, you can do a lot of 
testing without the P2 extender.


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