From: Eric Allman <tuhs@eric.allman.name>
To: Noel Chiappa <jnc@mercury.lcs.mit.edu>, Will Senn <will.senn@gmail.com>
Cc: tuhs@tuhs.org
Subject: Re: [TUHS] Upgrading from 11/40 to 11/45 in Unix v6
Date: Mon, 31 Dec 2018 17:56:16 -0800 [thread overview]
Message-ID: <647c9a7e-31da-9940-ece9-ce355ef36a52@neophilic.com> (raw)
In-Reply-To: <20181231065125.2A34818C073@mercury.lcs.mit.edu>
On 2018-12-30 10:51 PM, Noel Chiappa wrote:
> > From: Will Senn
>
> > Do you know of some commonly used at the time v6 programs that needed
> > that much space?
The base system probably didn't have any separated I/D space programs
for reasons that have already been discussed. But users definitely did.
For example, the INGRES database system at Berkeley required separated
I/D space (and even then ran in multiple processes). Tom Ferrin at UCSF
Computer Graphics Lab needed it as well.
Speaking of Tom and the 11/45, there was a quirk in the MFPI (Move From
Previous Instruction Space) instruction that broke the nargs() function,
which was pretty heavily used at the time. Tom gave an amazing
presentation at USENIX in San Francisco where he fixed the problem by
cutting a trace on one of the circuit boards. It's described here:
https://www.cgl.ucsf.edu/home/tef/pubs/mfpi.pdf. If you're using
nargs() then there might be a reason to stick with the 11/40, assuming
your implementation doesn't have the Ferrin Fix.
eric
next prev parent reply other threads:[~2019-01-01 2:27 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-31 6:51 Noel Chiappa
2018-12-31 15:06 ` Will Senn
2018-12-31 15:50 ` Clem Cole
2018-12-31 15:53 ` Warner Losh
2018-12-31 15:59 ` Clem Cole
2019-01-01 1:56 ` Eric Allman [this message]
-- strict thread matches above, loose matches on Subject: below --
2018-12-31 18:38 Noel Chiappa
2018-12-31 20:06 ` Warner Losh
2018-12-31 17:20 Noel Chiappa
2018-12-31 2:25 Will Senn
2018-12-31 2:43 ` Clem cole
2018-12-31 3:31 ` Will Senn
2018-12-31 14:55 ` Clem Cole
2018-12-31 15:05 ` ron
2018-12-31 15:53 ` Clem Cole
2018-12-31 17:30 ` ron
2018-12-31 18:20 ` Paul Winalski
2018-12-31 2:47 ` Clem cole
2018-12-31 3:08 ` Will Senn
2018-12-31 3:15 ` Clem cole
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