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From: chris@umcp-cs.UUCP (Chris Torek)
Newsgroups: net.decus
Subject: Re: Bit 0, Vax-780, I/D Reg 0C
Message-ID: <2937@umcp-cs.UUCP>
Date: Wed, 13-Aug-86 22:48:42 EDT
Article-I.D.: umcp-cs.2937
Posted: Wed Aug 13 22:48:42 1986
Date-Received: Sat, 16-Aug-86 06:50:18 EDT
References: <30600007@uiucdcs>
Reply-To: chris@umcp-cs.UUCP (Chris Torek)
Organization: University of Maryland, Dept. of Computer Sci.
Lines: 12

In article <30600007@uiucdcs> irwin@uiucdcs.CS.UIUC.EDU writes:
>I have a question relating to a VAX-780 or 785.
>What is the zero bit used for in the I/D Register 0C??

Register 0C is the SBR (System Base Register).  Bits zero and one
`MBZ', as DEC puts it in the _VAX Hardware Handbook, 1986_.  If
you set them, the machine's behaviour is probably `UNPREDICTABLE'
(as DEC handbooks like to say).
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 1516)
UUCP:	seismo!umcp-cs!chris
CSNet:	chris@umcp-cs		ARPA:	chris@mimsy.umd.edu