On 26 Feb 2009 at 20:55, Dennis Boone wrote:
> Probably
didn't hurt that the PPU was a 12-bit machine...
Or the CPU word was 60 bits.
But the CPU had no I/O. The PPUs transferred data out of CM into their
local memory through the pyramid to write it, or vice versa for reads.
No, but it's generally a CPU program that initiates a punch job. So
60-bits = 5 columns in column binary, which fits nicely. I don't
even remember the name of the CIO overlay that drives the 415. Thing
was noisy and prone to trouble so few people used it. I do remember
the nice warm feel of a deck of freshly-punched cards, though.
---Chuck