| Title: | Early Digital RISC architectures |
| Notice: | So early, we didn't *KNOW* they were RISCy! |
| Moderator: | ATLANT::SCHMIDT |
| Created: | Tue Feb 27 1990 |
| Last Modified: | Fri May 09 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 210 |
| Total number of notes: | 1350 |
I've got a 1980 DEC Datasystem.... 11/34a and a couple of RL01s.
One of the RL01s has quit working. The "ready" light no longer
lights and you cannot open the door. When opening the door from
the panel on the side (defeating the lock), the spindle is rotating
slowly. That is described in the docs as normal behavior for about
15 seconds, at which point it stops and the "ready" light lights. The
spindle is not stopping.
Applying power to the unit (with the cpu off) lights the drive light
and the fault light. Not the ready light. Turning on the cpu turns
off those lights.
I'm running RT-11 V5.6, XM MTTY monitor (the system has a DZ-11).
The other drive boots and runs fine.
This does not kill the system as the 256KB memory is exactly enough
(with 16 blocks to spare!) to create a VM, put enough up there to
run the machine and do I/O with VTCOM/TRANSF between the 34a and a
PRO350 in another part of the house.
I have all the documentation but no diagnostics.
If anyone has any thoughts on this, I'd appreciate hearing from you.
Thanks,
Charlie
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 207.1 | ATLANT::SCHMIDT | See http://atlant2.zko.dec.com/ | Mon Feb 24 1997 21:30 | 30 | |
Charlie:
> Applying power to the unit (with the cpu off) lights the drive light
> and the fault light. Not the ready light. Turning on the cpu turns
> off those lights.
I believe THIS was normal behavior. If the drive isn't getting
the clock (and a constant data stream?) from the controller,
it calls this a fault.
-=-=-=-=-=-
I don't recall how the spindle motor control circuits of the
RL01/2 worked, but I'd expect that if you have a second, working
drive, you could compare things pretty easily. This was still
back in the days when things were built out of small-scale
integration and discrete parts, and could actually be fixed.
It sounds like your drive is keeping the electronic brake applied;
that's why the spindle continues turning slowly. Try giving the
spindle a turn with your hand and see if there's a lot of drag.
Atlant
P.S.: On the other hand, if you were getting seek errors, I could
teach you how to tighten up that #^@%$@ dial-cord positioner.
I once wore one of those out *several times over* discovering
that the RSTS/E driver's error handler wasn't properly recov-
ering from RL02 seek errors.
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