DEC OSF/1 for i386?

[Gary Grebus]

On 4/29/22 10:45, Dennis Grevenstein wrote:
> Hi,
> 
> just recently I found this archive:
> 
> https://vetusware.com/download/OSF1%20Source%20Code%201.10/?id=11574
> 
Cool!

  this is a package of source code for DEC OSF/1 V 1.0. I knew that this is
> supposed to run on DECstations (with MIPS), in fact I have a DS3100
> running it myself.
> However, one thing really puzzled me: This archive apparently includes
> support for i386. There is even a kernel build log from 1990.
> Now that was news to me. I never realized that this worked on i386.
> Can anybody here tell any stories about this?

I was working in AlphaServer hardware engineering at that time, so I 
wasn't directly involved but from what I remember...

The i386 parts of the tree are remnants of the OSF consortium code base 
which derived from Mach.  That original code supported the DS3100 (PMAX) 
so there would never have been any reason to run it on i386 at DEC.

I think DEC OSF/1 V1 was only ever an "Advanced Developer" release for 
the DS3100 (and maybe the DS5000 systems aka 3MAX).  The "official" UNIX 
for all the MIPS platforms was still MIPS Ultrix.

At that time (1992), the UNIX strategy was even more chaotic than usual, 
since DEC had committed to the transition from Ultrix to the "industry 
standard" OSF/1, at the same time all the MIPS plans were being derailed 
by the pending arrival of Alpha.  This created an incredible headache 
for the OS development folks.  The group actually ended up being split, 
with most of the team working on keeping Ultrix going, and 
"productizing" OSF/1, while an "advanced development" team across the 
river in Hudson, NH did the hardware port to Alpha.  That was definitely 
an "all hands" effort, including software guys who were drafted from the 
hardware teams, and some folks from the System V UNIX team in New Jersey 
(oh yeah, DEC also had a System V UNIX product at the same time to sell 
to the phone companies).

FWIW, much, much later, when the product was Compaq Tru64 UNIX, there 
actually was a port to X86-64 that booted and ran.  But it was never 
more than an engineering prototype.