Re: DECstation 2100: power trouble?

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

>>>> I tried turning it on.  [...lights acting odd...]
>>> Lights at EF would be memory.  [...]
>> Where are these documented?  [...].  Is this the PDF you mention
>> below?  I'll have to look for a copy.
>  No, that's for the PSU only, and the rest is different.

Ah, ok.

> The code is from "DECstation 2100/3100 Operator's Guide".  It's
> available online.

I'll have to try to scare up a copy; it sounds like something I should
have on hand.

>> But then I noticed a jumper between two of the pins on the miniDIN-7
>> marked with a mouse icon.  I removed that [] and, while it took some
>> seconds from powerup, I got a KN01 V7.0 banner on the printer port
>> serial line (nothing connected but power and serial).  It got to
>> test 3 ("7..6..5..4..3..") and then I got a ?? getting erased and
>> redrawn on the next line.
> Yep, it's what you get with no keyboard or mouse connected, it stops
> at "3".   A VSXXX-AA or -GA mouse will do, as will an LK201, LK401,
> LK421, or a similar keyboard.  Unsure of a loopback.

I'll have to see what I have.  If the jumper I mentioned counts as a
loopback, then I guess mine doesn't pass selftest with a loopback; I
never got anything on the printer serial port until I removed it.

> Next would be "2" for the network connection.

I've got it connected to an AUI-to-10baseT microtransceiver.  It works
well enough to do diskless boot up to the crash when it tries to start
the kernel.

> A dead battery pack will also cause you similar trouble [...]

Is there any easy way to tell whether mine is dead?  (I suspect so,
since I think it's been sitting on the shelf for years....)

> The most reliable way to force headless operation is to remove the
> VSIMM.

Is that the SIMM slot (made of white plastic) about 15% longer than the
main memory slots (which are black plastic)?  If so, mine does not have
one and as far as I know never has.

> The system will then switch to the serial port console automatically.

Didn't seem to do that for me, not until I removed that mouse jumper.
Perhaps I had the jumper in the wrong place and it was wedging as a
result?

>> [...] - btw, is there documentation on the console command language?
> See the operator's guide for most commands.

I definitely will have to scare up a copy then.

>> KN01 V7.0 
>> 08-00-2b-14-8c-7e
>> 0x00000000
> NB the hex number above is the amount of RAM the console firmware
> thinks the system has.

!

> At zero it may well be confused,

I'd say it most certainly is confused.  test -c reports 24 megs, and
indeed all the main RAM slots are filled.

> you do want to complete the power-on diagnostics.  A successful
> power-up looks like:

> KN01 V7.01

> 7..6..5..4..3..2..1..0

> 24Mb..........0

> KN01 V7.01
> 08-00-2b-xx-xx-xx
> 0x01800000
> >> 

> (of course the amount of RAM will vary).

So I need to find mouse and keyboard, or something close enough to keep
the ROM happy.  Were these never intended to be used without mouse and
keybaord even if they have no VSIMM installed?  I can't think why
selftest would fail without mouse/keyboard if serial console is
supported.

>> >> boot -f tftp()
>> 1845632+65024+374812-47c xfr addr: 0x80030000
>> 
>> Excptn:    <vtr=NRML>
>> Excptn pc: 0x801c9670
>> Creg:      0x1000001c<CE=1,EXC=DBE>

> A Data Bus Error exception.  Sadly little information is given here
> as to the circumstances and it could be just about anything, from a
> software bug to all kinds of hardware faults, such as a bus timeout
> or a memory parity error (did I suggest cleaning memory modules?).

You did.  It _could_ be a software bug, but that strikes me as
unlikely; I'm booting off a saved diskless pmax setup that worked
enough to boot back in 2021, so unless the disk has got corrupted since
then the software proper should be fine.

I did wiggle each SIMM in its socket, but I didn't pull them out.  I
may try that if other things don't help, but with the designed-for
insertion limits as small as they are I would rather not play with the
RAM unnecessarily.

>> I am feeling I may have dead hardware on my hands. :-(
> So far I haven't seen anything truly fatal,

That is encouraging!

> these all seem usual issues with a piece of old hardware that hasn't
> seen use for a while and got a bit dusty, etc.  Try issuing:

> >> t a

> at the console prompt for extensive testing and do consider cleaning
> memory modules.  You may try leaving only the first bank occupied.

Which slots make up the first bank?  That is probably in one of the
PDFs I need to find, but if you can tell me before I dig up a work
machine to fetch things with I may be able to get going sooner.

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