Find of the day

From: Dave McGuire <>
Date: Wed Sep 15 17:03:47 1999

On Wed, 15 Sep 1999, Jim Strickland wrote:
>> 1 CPU? it has two interesting-looking chips:
>> 1: LSILIA 0485, 21-23413-01, DC379, TAC 8546
>> 2: LSILIA 0486, 21-23389-01, DC379, CAC 8544
>> This is connected to a DB9M in the back panel (console goes here?
>> what is the pinout? what is the funny-labeled rotary switch next to
>> it?)
>Dunno what the chips are, probably part of the vax chipset. That db9 is your
>console socket. It's a straight rs232 terminal port. The rotary switch (if
>memory serves) determines where in the boot cycle it goes to. In one position
>it stops at the >>> (bios, more or less) prompt. In another it autoboots the
>OS. I'm trying to remember if halt is on that switch or seperate, and I think
>it's separate.

  It is separate...its a toggle switch next to the boot action rotary switch.
The >>> business is more commonly referred to as the "rom monitor".

>The dec memory board appears to be a 4 meg memory board. Since the machine can
>address only 16 megs of ram, and since if memory serves it has a meg on the
>mainboard, I'm going to hazard a guess here and guess the nemonix is an 8 meg
>memory board, giving you 13 megs total. Not a bad amount at all. The uVax2s
>that were part of a cluster I once ran ran VMS 5.5 in only 16 megs, and my
>vaxstation 3100 does 7.2 (I think) on 8 megs. Ultrix runs nicely in 13 megs,
>too, although compiling gcc took all day on the ultrix box with 13 megs that I
>tried it on.

  13mb is indeed a reasonable amount of memory for a VAX. VAXen are *very*
memory efficient. On a 3100/m38 running Ultrix 3.1, I had two compiles and an
emacs session running, with X, on a 16mb system...with *NO* swapping!

  There is 1mb of RAM on the KA630 CPU board, and the max RAM is 16mb for that
CPU. If you put two 8mb boards into the system, the onboard 1mb of RAM is

>> 4 dec board, some labels are: LPWR M94V-1 25787, and "M7516" in the
>> extraction handle; connected to a DB15F in the back panel
>Not a clue here, although dec uses db15 for video on Vaxstation 3100s, so I
>suspect it's a graphics card.

  M7516 is an ethernet card, otherwise known as DELQA. It is the faster of the
two common Qbus ethernet cards. The DB15 connector is an AUI
can get a transceiver to go to 10baseT or whatever network hardware you're

>> 5 dec board, (disk controller?), reads M7555 in the extraction handle,
>> connected to what seems to be an older RLL hard drive

  MFM, not RLL. The M7555 is otherwise known as the RQDX3 disk controller. A
nice board. It controls up to two floppy drives (RX50 or RX33) and up to two
hard drives. Here's a list of the hard drives it supports, their approximate
capacities, and their original manufacturer and part number:

  RD50 5mb Seagate ST506
  RD51 10mb Seagate ST412
  RD52 35mb Quantum Q540
  RD53 71mb Micropolis 1325
  RD54 159mb Maxtor XT-2190
  RD31 21mb Seagate ST225
  RD32 42mb Seagate ST251

>> Hard drive: RD53-A rev A
>Yup. RD53 is an RLL 40 meg, I think. Not very reliable in my experience.

  71mb. Prone to spindle motor controller failures.

>Somewhere on the system is probably a tk50 tape drive, too. Slow and not
>very high density per cartrige, but they work.

  TK50 is 95mb...not very useful for backups due to small capacity, but they
were (are) commonly used as a software distribution medium.

>> So what exactly is this beast and how can I test if it works?

  Well, get yourself an ASCII terminal and plug it into that db9. Power it up,
and you should see the CPU identify itself (it's a KA630) and then you'll see a
countdown. It'll take a few minutes. Each number that it prints is another
part of the power-on diagnostics. If all goes well, you'll either start to
boot whatever OS is on that RD53, or you'll land at a ">>>" prompt.

  That machine is capable of running Ultrix, VMS, or NetBSD, by the way. It's
a bit slow by today's standards, but it still can be very useful, and lots of
fun to run. You have an easy in-box upgrade path to the KA650 CPU
(MicroVAX-III) by swapping the CPU and memory boards...makes it about three
times faster and increases the addressable RAM to 64mb IIRC.

  Good luck, and please don't hesitate to post questions here.

                      -Dave McGuire
Received on Wed Sep 15 1999 - 17:03:47 BST

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