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From: jack@boring.UUCP
Newsgroups: net.unix-wizards
Subject: Re: UNIVS: Unix for J-11 or 11/84
Message-ID: <6858@boring.UUCP>
Date: Sat, 5-Apr-86 14:42:48 EST
Article-I.D.: boring.6858
Posted: Sat Apr  5 14:42:48 1986
Date-Received: Wed, 9-Apr-86 08:32:36 EST
References: <183@cybavax.UUCP> <6552@utzoo.UUCP>
Reply-To: jack@mcvax.UUCP (Jack Jansen)
Organization: AMOEBA project, CWI, Amsterdam
Lines: 30
Apparently-To: rnews@mcvax

In article <6552@utzoo.UUCP> henry@utzoo.UUCP writes:
> [Replying to an article asking how to configure V7 for a J-11]
>
>Long odds you will find that the thing acts pretty much like a 70 as far
>as Unix is concerned.  To V7 Unix, with the exception of one or two fine
>details of which registers are printed in the event of a memory-system
>error, a 44 looks *exactly* like a 70 with Unibus disks.  The "Unibus
>disks" part requires a couple of small changes to the bootstrapping code,
>which ignores the Unibus map since Bell Labs's 70s had Massbus disks and
>45s didn't have the map.

Quite right, but the gotcha is in the 'couple of small changes'.
It took me *weeks* to find out why the machine didn't boot.....
Anyway, for those of you facing the problem (I tried sending the
original poster some info, but it bounced): The problem is that
the unibus map is turned on very soon in initialization. This means
that non-massbus devices won't be able to load the kernel, since
the mapping is incorrect. Wait with turning the map on until your
kernel is more-or-less running. I think I did it somewhere in main(),
after counting memory.

Something else: If my memory serves me right, a J-11 doesn't have
separate I/D. This would make it look more like an 11/34 with with
a 22 bit bus, or an 11/24+ (I think).
If you have a standard V7, this might give you some problems. I seem
to remember that there's some unibus map code that is only enabled when
you run on a separate I/D machine.
-- 
	Jack Jansen, jack@mcvax.UUCP
	The shell is my oyster.