> On Jul 14, 2015, at 3:55 PM, William Donzelli <wdonze...@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
