Reproducing old machines with newer technology

[Paul Koning]

> On Jul 14, 2015, at 3:55 PM, William Donzelli <wdonzelli at gmail.com> wrote:
> 
>> ...I/O processors.
> 
> I do not think you can claim that the 6600 I/O processors were all
> that new. Many (most?) of the 1960s mainframes before the 6600 had
> channel controllers.

Sure, but channel controllers and PPUs are very different beasts.  You can’t run your OS on a channel controller, which is exactly what Cray did on the 6600.  Nor can you implement the entire operator user interface on a channel controller, as was done in the DSD PPU program.

	paul