On 10/3/2019 10:01 AM, Noel Chiappa via cctalk wrote:
From: Paul
Koning
Some early machines, the PDP-6 I believe is an
example, have
"registers" in the ISA but they actually correspond to specific parts
of main memory.
The PDP-6 and KA10 (basically a re-implementation of the PDP-6 architecture)
both had cheapo versions where addresses 0-15 were in main memory, but also
had an option for real registers, e.g. in the PDP-6: "The Type 162 Fast
Memory Module contains 16 words with a 0.4 usecond cycle." The KA10 has
a similar "fast memory option".
Noel
The PDP-5 how soon theyy forget. The PC was in core memory for sure.
Not sure about the AC how ever.
The IBM 1130 had the index registers in Core at something like 1,2,3.
Today Fast memory is .4 ps. I wonder how the old machines
would compare with today's wonder CPU's assuming the same transistor
speeds.Ben.