Article View: comp.arch
Article #21109Re: unconventional architectures
From: Dave Collier-Brown
Date: Sun, 07 May 1989 17:24
Date: Sun, 07 May 1989 17:24
27 lines
1887 bytes
1887 bytes
>In article <89May6.165030edt.10782@ephemeral.ai.toronto.edu> bradb@ai.toronto.edu (Brad Brown) writes:
| >... we looked at a lot of old machines that had all kinds
| >of really neat features that you just don't see any more. My favorite
| >was the Buroughs 6600 (?) and it's segmentation scheme...
| >... a lot of access bugs could be detected
| >at runtime with no performance penalty...
In article <1989May6.234007.23517@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
| Unless you count the performance penalties implicit in implementing the
| rather complex design. One can debate the size of said penalties, but it
| isn't correct to say that the bug detection is free.
Well, it doesn't seem to add any extra overhead to the memory address
computation on a Honeywell, but I can't say for sure if the time taken
is actually dominated by instruction decoding, etc. I'd guess "yes" on
the older series 66 line, and a rather strong "no" on the DPS-90
(NEC-designed) machines.
Designing a CISC is hard, but sometimes one finds that "wasted" time can
be usefully filled up. The risc people seem to have noticed this too (;-))
--dave
--
David Collier-Brown, | {toronto area...}lethe!dave
72 Abitibi Ave., | Joyce C-B:
Willowdale, Ontario, | He's so smart he's dumb.
CANADA. 223-8968 |
Technical Details
Message-ID:
<2479@lethe.UUCP>Path:
arc1-ca.pugleaf.net!utzoo!mnetor!tmsoft!dptcdc!lethe!daveReferences:
<112@centaure.UUCP> <422@unicads.UUCP> <11579@cgl.ucsf.EDU> <89May6.165030edt.10782@ephemeral.ai.toronto.edu> <1989May6.234007.23517@utzoo.uucp>Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!mnetor!tmsoft!dptcdc!lethe!dave From: dave@lethe.UUCP (Dave Collier-Brown) Newsgroups: comp.arch Subject: Re: unconventional architectures Summary: memory protection on ciscs Message-ID: <2479@lethe.UUCP> Date: 7 May 89 17:24:16 GMT References: <112@centaure.UUCP> <422@unicads.UUCP> <11579@cgl.ucsf.EDU> <89May6.165030edt.10782@ephemeral.ai.toronto.edu> <1989May6.234007.23517@utzoo.uucp> Reply-To: dave@lethe.UUCP (Dave Collier-Brown) Organization: Officially bimodal, news courtesy of Systems Software Lines: 27