16 Dec
2008
16 Dec
'08
1:32 p.m.
From: Paul Koning
Sent: Tuesday, December 16, 2008 9:26 AM
>>>> "Rich" == Rich Alderson
<RichA at vulcan.com> writes:
Rich>> From: Andy Holt Sent: Friday, December 12, 2008 2:15 AM
>> ...The RISC before there ws RISC:
>> *CDC6600
Rich>> The PDP-10 is often described this way.
Interesting. I wouldn't, for a couple of reasons.
The PDP-10
instruction set is quite large. Also, RISC generally means load/store
instructions and the rest of the ops are register based. CDC 6000
series does that, as do contemporary RISC architectures like MIPS --
but the PDP-10 doesn't.
I'm well aware of where the PDP-10 architecture fails that definition.
On the other hand, nearly 30 years of programming the PDP-10 architecture
tells me that very nearly all the work done by a PDP-10 program is done
with accumulator load/store and accumulator-to-accumulator or accumulator
+ immediate data operations.
And the size of an instruction set is not indicative of the RISCiness of
the architecture.
Rich Alderson
Server Engineer, PDPplanet Project
Vulcan, Inc.
505 5th Avenue S, Suite 900
Seattle, WA 98104
mailto:RichA at vulcan.com
(206) 342-2239
(206) 465-2916 cell