15 Dec
2008
15 Dec
'08
6:09 p.m.
From: Andy Holt
Sent: Friday, December 12, 2008 2:15 AM
The two pre-micro classics, nay extremes, of CISC:
*IBM system 360/370/... [Multi-GP-register - store
organisation with a
sprinkling of store-store operarions]
I missed this observation the first time. You've obvioiusly never
run into a CDC STAR-100. 48 bit virtual addressing (bit addressed),
256 64-bit registers with an instruction set that, while it allocated
8 bits to the opcode, used a second 8-bit field (the "G" bits) in
many instructions yielding thousands of variations (that included
strings (including BCD arithmetic) and vectors (including sparse and
compressed). If you ever hankered after a "polynomial evaluation" or
byte-string modulo addition (with variable modulus) instruction, the
STAR had it for you.
Postively and grotesquely baroque in in the range of instructions.
The hardware reference manual is on bitsavers; most of the almost 19
megabyte text is instruction descriptions. The one for "Search
Masked Key Byte" occupies 3 pages alone.
The "kitchen sink" of supercomputers.
Cheers,
Chuck