11/34A/RK07 not booting. Help wanted

From: Christian Fandt <cfandt_at_netsync.net>
Date: Thu Nov 19 20:55:52 1998

At 01:40 11/20/98 +0000, Tony Duell wrote:
  -- snip --
>>
>> Seems I recall you or somebody having a problem with confusing cables and
>> reporting it here some time back. Therefore I was careful to keep the RK
>> cables and RL cables separated when I picked up this truckload of DEC gear
>> back in July. The RK cables were kept w/the RK's. I'm quite sure the
>> correct cable is strung between the RK07 and the flat cable from the RK611.
>> BUT, I'll check to make darned sure the previous owner didn't swap them
>> around! I recall there's an ID tag on that cable w/part number. I'll check
>> it out.
>
>If you open up the plug shell on one end of the cable (it clips
>together), you can see the wiring. If almost all pins have wires (I think
>one is not connected - it's essentially TERMPWR) then it's an RK07 cable.
>If about half the pins are wired, it's an RL cable.

Good tip. I'll check that tomorrow.
 
>
>>
>> >
>> >You've got the ribbon from the RK611 to the bulkhead adapter connected
>> >the right way round. Try turning one end over - it won't do any damage if
>> >it's wrong, but it sure won't work.
>>
>> I'll try turning it over. I could have accidentally turned it over while
>> doing the pre-powerup checkout (had all the boards out.) I'm usually quite
>> careful like you when yanking stuff apart and putting it back together.
>
>We all make mistakes (or at least I do :-)). It is worth checking this.
>Why DEC didn't use polarised connectors here is a mystery to me...

This is indeed a bone-headed thing DEC did. I bet a lot of field engineers
were cussing about that. Must have been two different design departments
between RK's and RL's (Allison. . . comments?)

>
>> >Just to check for a silly again - pull the 'A' cap and the bulb. Test
>> >said bulb. We don't want to be searching for nasty faults if all the time
>> >it's been working but the disk isn't bootable...
>>
>> Hmmm, I'll check that but there is absolutely no disk activity when I
>
>OK... Doesn't _sound_ like a dead bulb, then.

I have a bulb extractor somewhere around in one my toolboxes. Could still
be buried. We recently moved you may recall. I'll try to hunt it up and
check for sure with an ohm meter.

>
>If you swing out the RK07 cardcage, there are some LEDs on the edges of
>some of the boards. There should be a plastic cover over the end the
>labels them, but if not, I think they're in the user manual. If you can't
>find anything, then I'll find out for you.

I'll let you know what's up with them.

>
>IIRC, the RK07 spin-up is something like : Motor up to speed, brush cycle
>(old drives only), positioner unlocks and moves to outer guard band,
>postioner moves to spindle and back to track 0. Does yours do that?

Seems right recalling the several times I've watched this process on the
RK. I'll check for sure. Track 0 is at the outer edge I assume?

>

>> enter DM at the console. I had the cover off the back of the RK07 so I can
>> see any hint of head motion. I would think that at minimum one stroke of
>> the head actuator would scan for bootable code at this point. Nada.
>
>Hmmm.. The positioner would be on track 0 after a spinup, and the
>standard boot is to read track 0, sector 0 into memory
>and jump to the start of it. So you might not see any head movement if
>there's nothing bootable on the pack.

I see. Of course with absolutely no prior knowledge of such details as this
I am completely oblivious to what should be what. Now is the time to learn.

>
>Another useful trick is to look at the RK611 registers after the
>attempted boot. Do they look at all sane? Any errors?

This is the first day ever of me even operating an 11/34A. I'll have to
figure out from the rather terse instructions in the user's manual how to
find and examine registers. At least the Programmers Console has a variety
of good features for this.

I'll also report what the registers say on the CRT console after I enter
the 'DM' and the '_at_' prompt comes back. Could be something there you folks
could extrapolate.

Thanks again for now, Chris
-- --
Christian Fandt, Electronic/Electrical Historian
Jamestown, NY USA cfandt_at_netsync.net
Member of Antique Wireless Association
        URL: http://www.ggw.org/freenet/a/awa/
Received on Thu Nov 19 1998 - 20:55:52 GMT

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