4.3BSD Quasijarus

[Ethan Dicks]

On Sat, Dec 27, 2008 at 11:40 AM, Dave McGuire <mcguire at neurotica.com> wrote:
>> netbsd wants more memory than I have and the 730 guts were slightly off.
>> I've gotten close to fixing it but not yet.
>
>  How much memory does your system have?  I'd love to see NetBSD on the
> 11/730.

The 11/730Z configuration (same backplane as for the 11/725) only has
room for five 1MB boards.  I don't know about the later 11/730
packaging, the one that looks like it's in a BA-11-type box at the top
of a 42" cabinet (reminding me a little of a skinny 11/750).  I never
had one of those, and after the limitations of the -Z packaging, was
always curious about it.

The -Z is nice if all you need is a CPU, an RB80 disk, an RL02, 5MB of
memory, a DMF32, and perhaps a tape drive or a couple of SPCs.  You
can run an external BA-11 (we did), but having a side-along cabinet
sort-of defeats the purpose of the integrated packaging.

The 11/725 can also be rigged with a BA-11 (I've seen it done, but
haven't done it myself), but it helps to nibble out a notch in the
outer skin to pass the Unibus cable out.  Electrically, it works, but
it was never a supported configuration, and there's no pre-made way to
deal with cable issues.

8MB on an 11/750 is adequate for many things.  5MB on a KA730 is much
more constrictive.  I know they were balancing models and trying not
to cannibalize high-end customers on a cheaper package, but we found
memory, not CPU speed (slow as it is) to be the ultimate limiting
factor with those models.

-ethan