PPU (was: Virtual memory

Fred Cisin cisin at xenosoft.com
Tue Nov 9 16:15:53 CST 2010

> In the 50s the main processor was called the CPU (Central Processing
> Unit) to differentiate it from the various PPUs, (Peripheral
> Processing Units).

A helluva lot of beginning computer courses now, and back to mid 1960s
introduced the term CPU, and sometimes ALU, but don't/didn't mention PPUs.

> The first machine I programmed, the IBM 7094 had a
> CPU and two PPUs, one to read cards and write the images to tape
> transports, which would then be switched over to the CPU to read,
> compile and execute the job and write the results back to another tape
> transport which then got switched to the other PPU which then
> transferred the tape image to a line printer.

I did some FORTRAN on a 7094 at GSFC (SSDC Bldg 26) 40 years ago.  They
were using a 360/30 to do I/O for the 7094!  Would that make that 360 a
PPU :-?

Grumpy Ol' Fred     		cisin at xenosoft.com

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