[TUHS] Re: 3B21D

[Kevin Bowling <kevin.bowling@kev009.com>]

On Thu, Jul 4, 2024 at 1:22 PM segaloco <segaloco@protonmail.com> wrote:
>
> On Thursday, July 4th, 2024 at 1:14 PM, Warner Losh <imp@bsdimp.com> wrote:
>
> >
> >
> > On Thu, Jul 4, 2024, 2:02 PM Kevin Bowling <kevin.bowling@kev009.com> wrote:
> >
> > > Howdy,
> > >
> > > I now have this pictured 3B21D in my facility
> > > http://kev009.com/wp/2024/07/Lucent-5ESS-Rescue/
> > >
> > > It will be a moment before I can start work on documentation of the
> > > 3B21D and DMERT/UNIX-RTR but wanted to share the news.
> >
> >
> > Awesome accomplished. Can't wait to see the outcome.
> >
> > Warner
> >
> >
> >
> > > Regards,
> > > Kevin
>
> Kudos, I'm quite envious, this is awesome news!  I appreciate your writeup, touching on the odd world this lives in, between computer and telecom appliance.  Whether the 3B20 family was liked out in the general computing world or not, the impact on telecommunications is clear with the long shadow of the 5ESS family of switches.

Thank you.  The goal is to share the system, virtually and physically,
with interested parties.

> Hopefully Lucent was still keen on providing /usr/src and /usr/man :)
>
> I'm still holding out hope a WECo-era machine pops up someday...but either way, glad to finally see something in this lineage in the hands of someone with a keen eye for UNIX and Bell System history!

I'm not sure myself how similar the 3B20 and 3B2 are and it will be a
topic of inquiry since I now have the ability.  My initial impression
is that the 3B20 is a fully custom logic and microcoded minicomputer
specific to the fault tolerant and DMA I/O administrative workload it
was designed for.  You can get a flavor of what custom control entails
from Wing N. Toy's books and some of the BSTJ articles on the 5ESS as
this is a forgotten design skill.  The 3B2 is a more common
microprocessor minicomputer and not far removed from a VAX of similar
age.  I don't believe there is explicit compatibility between the 3B20
and 3B2, although a 3B20S running SysV would offer a high degree of
source compatibility.

I'm sure you've seen it but I will plug Seth Morabito's 3B2 emulator,
you can get a very good feel for what a 3B2 UNIX is like (not that
great :)) from it.

>
> - Matt G.