Path: utzoo!attcan!uunet!husc6!psuvax1!rutgers!mailrus!cornell!uw-beaver!teknowledge-vaxc!sri-unix!garth!smryan
From: smryan@garth.UUCP (Steven Ryan)
Newsgroups: comp.arch
Subject: Re: dedicated vs general-purpose CPUs
Message-ID: <1173@garth.UUCP>
Date: 6 Aug 88 22:46:35 GMT
References: <5254@june.cs.washington.edu> <76700032@p.cs.uiuc.edu> <1988Aug3.180947.12070@utzoo.uucp> <1221@ficc.UUCP>
Reply-To: smryan@garth.UUCP (Steven Ryan)
Organization: INTERGRAPH (APD) -- Palo Alto, CA
Lines: 12

If you want an expensive example of a machine made of diverse processors,
consider the CDC 6600->170s. A machine consists of 1 or 2 60-bit CPs and
10 to 20 12-bit PPs. All the number crunching goes in the CP and the
io in the PPs with all processors in parallel. (Well actually, PPs share
a barrel.)

Most of the operating system for NOS actually runs in the PPs so that the
CP spends much of its time in user state.

The 180 retains the same philosophy with 64-bit CPs and 16-bit PPs, though
apparently NOS/VE uses the PPs as just drivers with operating system mostly
in the CP.