AMSYS29 floppies

[Dave McGuire]

On 11/22/10 4:12 PM, Tony Duell wrote:
>>   I have a S100 board that is said to be a math processor board
>> that has a single 2901 on it. I have the manual as well.
>
> I find that strange. A single 4 bit slice is not that useful. I asusme
> there arten;t 2903s as well :-)

   Well, 2901s were fairly expensive chips in those days, and it's 
certainly possible to do wider-than-four-bit math in a four-bit CPU. :)

> Althoguh AFAIK DEC never used them in a PDP11 CPU. There were, of
> course, used i nteh floating point processors for some PDP11s, and in the
> VAX11/730

   And the KS10 as well.  I wonder if there are any others; I don't 
think so offhand.

   One of my favorite uses of Am2901s is in the FPF11 floating-point 
processor.  For the non-PDP11-savvy, the FPF11 is a strange board that 
can be used in both Qbus and Unibus systems by changing jumpers near the 
card-edge connectors.  It uses a 40-pin ribbon cable to plug into a 
microm DIP socket in an F11-based PDP-11 (11/23 or 11/24).

              -Dave

-- 
Dave McGuire
Port Charlotte, FL