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Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxb!mhuxn!mhuxm!mhuxj!houxm!vax135!ariel!jlw
From: jlw@ariel.UUCP (J.WOOD)
Newsgroups: net.micro.6809
Subject: Re: more on RMS, and the Model 9?
Message-ID: <843@ariel.UUCP>
Date: Mon, 11-Feb-85 21:52:32 EST
Article-I.D.: ariel.843
Posted: Mon Feb 11 21:52:32 1985
Date-Received: Wed, 13-Feb-85 01:46:50 EST
References: <3500073@uokvax.UUCP>
Organization: AT&T-ISL, Holmdel, NJ
Lines: 23

Even with the new version of the SAM the 74LS785 is not a real
big upgrade for the SAM.  All it supports is 16kx4 rams and the
newer versions of the 64kx1 chips which were made as real 64kx1
rather than 4 16kx1 chips pasted together.  There is no support
for memory management or for true large address spaces.  Therefore,
unless the rather cryptic and unexplained statement made on both
data sheets, the 74LS783 and the newer 74LS785 one, that it supports
"Easy Synchronization of Multiple SAM Systems" is being used I
don't see how the new system will support OS/9 Level 2 which has
both large address space and memory protection.  It was intended for
either the SWTPc or the Gimix 6809 boards, both of which can support
up to a Meg of address space (incompatibly, I might add - sigh).
They use the newer definition of the SS50 buss the ss50c version
which steals the former baud rate lines of the earlier spec.



					Joseph L. Wood, III
					AT&T Information Systems
					Laboratories, Holmdel
					(201) 834-3759
					ariel!jlw