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From: mahler@usl-pc.UUCP (Stephen J. Mahler)
Newsgroups: comp.arch,comp.unix.wizards,comp.os.misc
Subject: Re: Shared libraries (Was: Re: Big Programs Hurt Performance)
Message-ID: <73@usl-pc.UUCP>
Date: Sun, 11-Oct-87 10:48:32 EDT
Article-I.D.: usl-pc.73
Posted: Sun Oct 11 10:48:32 1987
Date-Received: Thu, 15-Oct-87 01:43:29 EDT
References: <8714@utzoo.UUCP> <286@usl>
Reply-To: mahler@usl-pc.UUCP (Stephen J. Mahler)
Organization: Univ. of Southwestern La., Lafayette
Lines: 26
Xref: mnetor comp.arch:2632 comp.unix.wizards:4877 comp.os.misc:289

In article <286@usl> elg@usl (Eric Lee Green) writes:
>in article <8714@utzoo.UUCP>, henry@utzoo.UUCP (Henry Spencer) says:
>> Xref: usl-pc comp.arch:776 comp.unix.wizards:1359 comp.os.misc:161
>>> Needless to say, the Amiga OS is not Unix, for one thing, Unix isn't
>>> going to run on a 512K machine with no MMU and two floppies...
>> You might be interested to know that early versions of Unix ran on machines
>> on which 512KB would have been considered an impossible dream, with no MMU,
>> and with hard disks not much bigger or faster than modern floppies.  It was
>> a bit primitive by modern standards, but it did work.
>
>I assume you are talking about the PDP-11. The PDP-11 does have a MMU,
>which does address relocation (i.e. you have a virtual address space
>of 64K, located in a larger physical address space of 256K to
>4 megabytes depend on 18, 20, or 22 bit models). I've never used a
>PDP-11 :-).
>

DEC machines of PDP design included versions that did not include
MMUs.  The two that jump to mind are the pdp-11/20-15-10 and the
LSI-11/03 series.  UNIX ran on these machines.  The straight forward
approach was called MINI-UNIX.  It had features between V6 and V7
and the only real stripping of the OS was the removal of account "groups"
(/etc/group, newgrp, chgrp, etc.).  It did run on systems that had only
two floppies (like the AED 8 inch floppy system with about 1 meg per
drive).  It ran well, even from the portable generator on the
corn combine !!   .........  Steve