Article View: comp.sys.nsc.32k
Article #1605Re: Mod Table
From: Amos Shapir
Date: Tue, 06 Jun 1989 05:12
Date: Tue, 06 Jun 1989 05:12
21 lines
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1299 bytes
The mod table is anywhere the mod register points to; that means that each user can have as many tables as s/he likes; only one of them is active at any given time. The table has to be located in the lower 64Kb of memory, but that address is virtual; if a MMU is used, the address would be translated it to its proper physical location. The statement in the Grey Book (about the table being located in the first 64Kb of physical memory, and mapped to virtual address 0 in user space) is misleading - that's the way this is currently done in most implementations of UNIX, but this scheme is not dictated by hardware. Finally, on a 32532 in Direct Exception mode, the mod table can be completely ignored. -- Amos Shapir amos@nsc.com National Semiconductor (Israel) P.O.B. 3007, Herzlia 46104, Israel Tel. +972 52 522261 TWX: 33691, fax: +972-52-558322 34 48 E / 32 10 N (My other cpu is a NS32532)
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!voder!nsc!taux01!amos From: amos@taux01.UUCP (Amos Shapir) Newsgroups: comp.sys.nsc.32k Subject: Re: Mod Table Message-ID: <1814@taux01.UUCP> Date: 6 Jun 89 05:12:02 GMT References: <507@trwrc.UUCP> Organization: National Semiconductor (IC) Ltd, Israel Home of the 32532 Lines: 21 Hdate: 3 Sivan 5749