[TUHS] Re: ACM Software System Award to Andrew S. Tanenbaum for MINIX

[segaloco via TUHS <tuhs@tuhs.org>]

On Tuesday, June 18th, 2024 at 1:59 PM, Dave Horsfall <dave@horsfall.org> wrote:

> On Tue, 18 Jun 2024, segaloco via TUHS wrote:
> 
> > I have Andy Tanenbaum to thank in part for my interest in turning up
> > UNIX 4.0 information due to the quote:
> > 
> > "Whatever happened to System IV is one of the great unsolved mysteries
> > of computer science."
> > 
> > From Modern Operating Systems. I took this as an impudent challenge and
> > well here I am.
> 
> 
> Well, don't keep us in suspense; what happened to SysIV? Not that I'm a
> fan of either SysIII or SysV...
> 
> -- Dave

It has left its droppings out there in the world, some of which were held onto by Arnold Robbins: https://www.tuhs.org/Archive/Documentation/Manuals/Unix_4.0/

And others found by myself on eBay and reconstructed: https://gitlab.com/segaloco/pwb4u_man

The story I've gotten is AT&T policy was to release odd-numbered versions, so PWB 1.0, System III, and System V made it out into the world, PWB 2.0 and Release 4.0 stayed in the labs.  In the most technical sense, System IV never existed, what could've become it remained a Bell System-only issue.

- Matt G.