[rescue] I/O coprocessors?

[Scott Newell]

At 09:38 PM 3/1/2003 -0500, Dave McGuire wrote:
>   Almost...The PIC traces its lineage back to the General Instrument 
>8X300 family of microcontrollers.  It's a true microcontroller, not 
>really an I/O coprocessor.  Indeed. GI spun off its semiconductor 

>From http://www3.sk.sympatico.ca/jbayko/cpu1.html
"adapted by General Instruments for use as a peripheral interface
controller (PIC) which was designed to compensate for poor I/O in its 16
bit CP1600 CPU"

The I/O processor story has been told on usenet and the PICLIST for some
time as well.


>   The 8X300 and the later 8X305 were very popular in intelligent disk 
>controllers for minicomputers like PDP11s.  They didn't displace the 

Same site also claims the 8x300 started at Signetics...wow...that looks
like another strange design!


>"pair of 2901s and a 2910" setup that many designers used, but they 
>were popular nonetheless.

Incidentally, DACafe has the bitslice book online at:
http://www10.dacafe.com/book/parse_book.php?article=BITSLICE/index.html


>   I've got at least one of every popular (and not so popular) chip used 
>from the dawn of integrated circuitry up into the late 1970s...and I've 

How about an Intel neural network chip (Ni1000)?  Clipper crypto chip?  OK,
those are 90's era, but I'd sure like to have one of each as a collector's
item.  ;-)


>   I don't know of any in either of those families.  Dedicated I/O 
>processors seem to be limited to the mini/mainframe world.

Yep, that's why the 8089 intrigues me.


newell