Date: Sat, 12 Nov 2022 17:56:24 -0800
From: Larry McVoy <lm@mcvoy.com>
Subject: [TUHS] Re: DG UNIX History

It sounds like they could have supported mmap() easily. I'd love to see
this kernel, it sounds to me like it was SunOS with nicely done SMP
support. The guy that said he'd never seen anything like it before or
since, just makes me want to see it more.

I know someone who was friends with one of the kernel guys, haven't talked
to her in years but I'll see if I can find anything.

Following on from the exchange on TUHS about DG-UX, it would seem to me that the (Unix) unified cache was invented at least three times for Unix:

- John Reiser at AT&T

As to the latter I could find two leads that might help you finding out more. It would seem that this unique Unix is specifically DG-UX version 4:

Michael H. Kelly and Andrew R. Huber, "Engineering a (Multiprocessor) Unix Kernel", Proceedings of the Autumn 1989 EUUG Conference, European Unix Systems User Group, Vienna, Austria, 1989, pp. 7- 19.

The unified cache isn’t mentioned, but it would seem that the multiprocessor redesign might have included it. Maybe the author names are helpful. I could not find the paper online, but there was a web page suggesting that a paper copy still exists in a (university?) library in Sweden.

Publication: DG Review

Publication Date: 01-NOV-88
Author: Huber, Andrew R.

DG-UX 4.00: DG's redesigned kernel lays the foundation for future UNIX systems. (includes related article on DG-UX 4.00's file system and an excerpt from Judith S. Hurwitz's 'Data General's UNIX strategy: an evaluation' report)

COPYRIGHT 1988 New Media Publications

DG/UX 4.00

Revision 4.00 of Data General's native UNIX operating system siginificantly enhances the product and adds unique capabilities not found in other UNIX implementations. This article reviews the goals of DG/UX 4.00 and discusses some of its features.

When DG released DG/UX 1.00 in March, 1985, it was based on AT&T's System V Release 2 and incorporated the Berkeley UNIX file system and networking.

As DG/UX grew, it continued to incorporate functions of the major standard UNIX systems, as illustrated in the following timeline:

* DG/UX 1.00 March, 1985 Based on System V Release 2 and Berkely 4.1.

Included Berkely 4.2 file system and TCP/IP (LAN).

* DG/UX 2.00, September, 1985 Added Berkeley 4.2 system calls.

* DG/UX 3.00, April 1986 Added support for new DG hardware.

* DG/UX 3.10 March, 1987 Added Sun Microsystem's Network File System.sup.(R) Added X Windows.

* DG/UX 4.00, August, 1988 Re-designed and re-implemented kernel and file system.