4.3BSD Quasijarus

[Steven M Jones]

Bob Armstrong wrote:
>
>   Yes, the 725/730 is limited to 5Mb, although it's tricky to find enough
> slots for this if you've got any peripherals.  I have a 11/730 that's
> fortunate to also have the BA11-K UNIBUS expander box, so I've got room for
> 5Mb, but that was an unusual configuration.

Mine was also configured with an expander, but I only got the 730Z rack. 
Along with that I got up to a total of 4 or 5 1MB boards, a TC13(?) tape 
controller, and a Cipher F880 drive. Recently bought a DELUA for when I 
pick up a BA11, in case it's supported.


Ethan Dicks wrote:
 >
 > The 11/730Z configuration (same backplane as for the 11/725) only has
 > room for five 1MB boards.

My question is whether the Nebula was limited to addressing 5MB, or is 
it a matter of open/correctly-wired slots? Any way to get past 5 memory 
boards if you have a BA11, for instance? I don't have the machine or my 
UNIBUS VAXen handbook handy...


Bob Armstrong wrote:
 >
>   My 11/730 runs, except for the R80 which needs a new HDA (alas, Rx80 HDAs
> are pretty much unobtainium today)

The reason I was able to acquire the machine as surplus in 1990 was that 
the R80 was throwing bad blocks constantly, causing grief for the lone 
researcher that was using it as a big, noisy PC for running her FORTRAN 
code. I was able to connect her with another lab that had decommissioned 
11/750s lying around with racks of RA81 drives they were willing to 
provide via internal transfer.

In a fit of youthful idealism I pitched the entire R80 mechanism, 
figuring that SCSI was the One True Path and the IDC was supposed to be 
slow anyway. Well, and the fact that I had to find a nearly unused 
circuit from another room just to spin the thing up... Pretty dumb to 
toss it, but that's hindsight for ya.


Brad Parker wrote:
 >> [ running Quasijarus on a physical 11/730 ]
 >
 > Yes, I did it a few years ago and it worked fine for me.  As I
 > recall I ran it on a ra90 with a uda50.

Cool, my main concern was around support for the CPU. I recalled some 
fuss about the stock 4.3BSD distribution not having support for the 
730's data paths, or somesuch, and doubted that later flavors would have 
continued support for the Low Cost Node.


Ethan Dicks wrote:
 >
 > [...]  For that, our 11/730 with Ultrix 1.1 (4BSD covered in
 > DEC-hardware-specific scripts and other DECisms) with its 120MB R80
 > fit the bill better, even though the CPU was 75% as fast.

I recall that the only other 11/730 that I saw in service back in the 
day was running Ultrix and serving as little more than a print spooler 
for a line printer. Again this was ~1990 and the labs in question 
weren't hit with an electric bill for running these things in a way that 
encouraged conservation...

 > [...] but as a UNIX box, it screamed.

Heh -- I'm not expecting it to impress in that department. ;^)


--Steve.