Hi,

today I moved the RA81 from the garage down into the Laundry/Computer-
Room in the basement. Thanks to my straps and a hydraulic car jack-
stand I was actually able to install it in my TU81+ cabinet without
breaking my back or getting squished underneath the drive :-). It
looks really cool in the TU81 rack. I powered it up and though no
lights at these push-buttons come on, I could test it quite far.
Thanks to Will Kranz' abridged service manual

http://www.conknet.com/~w_kranz/pdp11/RA81.HTM

I knew what I could do with the terminal and that CTRL-C will
get it going (not CTRL-Z like with the TU81+) and after running
diagnostics once, I could actually spin up the drive. Just
seeking seems not to work.

Spun up diagnostigs gets the error

terminal plugged in, 300 b/s, 8 bit, 1 stop no parity

þ
^C

CTRL-C gets a prompt

  RA81> EUR^C

  RA81> EUR

turn serial port to 7 bit instead of 8 removes the junk

  RA81>

  RA81> RUN DIAGNOSTICS

%RA81-COMPLETED TEST:DIAG SUBTEST:02
%RA81-COMPLETED TEST:DIAG SUBTEST:01
%RA81-COMPLETED TEST:DIAG SUBTEST:07
%RA81-COMPLETED TEST:DIAG SUBTEST:08
%RA81-COMPLETED TEST:DIAG SUBTEST:0B
%RA81-COMPLETED TEST:DIAG SUBTEST:03
%RA81-COMPLETED TEST:DIAG SUBTEST:0D
%RA81-COMPLETED TEST:DIAG SUBTEST:19
%RA81-COMPLETED TEST:DIAG SUBTEST:1B
%RA81-COMPLETED TEST:DIAG SUBTEST:1C
%RA81-COMPLETED TEST:DIAG SUBTEST:1D
%RA81-COMPLETED TEST:DIAG SUBTEST:1E
%RA81-COMPLETED TEST:DIAG SUBTEST:1F
%RA81-COMPLETED TEST:DIAG SUBTEST:20

this was diagnostics spun down, everything successful! Now
I push the RUN/STOP switch in and there comes the sound of
the drive spinning up, really impressive!

  RA81> FRONT PANEL FUNCTION IN PROGRESS

then this message comes and a long time nothing, finally:

%RA81-TEST: SUBTEST:1B  ERROR:50  UNIT:001
%RA81-FRU-SLAVE RESPONSE FAIL- SERVO,MICRO

not knowing what else to do I do diagnostics again in spun
up mode

  RA81> RUN DIAG

%RA81-COMPLETED TEST:DIAG SUBTEST:02
%RA81-COMPLETED TEST:DIAG SUBTEST:01
%RA81-COMPLETED TEST:DIAG SUBTEST:07
%RA81-COMPLETED TEST:DIAG SUBTEST:08
%RA81-COMPLETED TEST:DIAG SUBTEST:0B
%RA81-COMPLETED TEST:DIAG SUBTEST:03
%RA81-COMPLETED TEST:DIAG SUBTEST:19
%RA81-TEST:DIAG SUBTEST:1B  ERROR:50  UNIT:001
%RA81-FRU-SLAVE RESPONSE FAIL- SERVO,MICRO

  RA81> RUN SEEK

ENDING CYLINDER? 1000

GROUP? 10
OPERATION FAILED


  RA81> RUN RECAL

%RA81-TEST:RECA SUBTEST:2A  ERROR:50  UNIT:001
%RA81-FRU-SLAVE RESPONSE FAIL- SERVO,MICRO

At no time I heard any seeking activity. Will's service manual page
says this:

 > D.28 TEST 1B (SERVO PLO TEST)
 > This test checks the servo module PLO circuitry.
 > Errors associated with this test are: 50, 7B, C6, FO to FE.

I don't see any system fault code on the led bits in the front of
the controller board with the hood open after the E7 "test in
progress" status byte is cleared. (So I do see the blinkenlights,
just there is no fault code besides the error message on the
service terminal.

Error 50:

 > 50   Ensure that positioner motor lock is in the unlock
 >      position. If OK, then replace servo module,
 >      microprocessor module

So, sounds like there is once chance for me: to find this
"positioner motor lock" and move it into the unlock position.
However, I have no idea how to do that? It sounds reasonable
that this thing may be locked for transport, I sure hope
so, because otherwise all my moving and installing this
thing would have been in vain.

any help with this is appreciated. Not that I depend on the
RA81 for operation, but I've got it and I believe in having
a VAX collection with 100% functional stuff.

regards
-Gunther


PS: Anyone having dead RA81's for parts? Anyone has spare
SDI bulkheads? I need one or two 2- or 4- port bulkheads
for the RA disks outside the SA600 cabinet.


-- 
Gunther Schadow, M.D., Ph.D.                    gschadow@regenstrief.org
Medical Information Scientist      Regenstrief Institute for Health Care
Adjunct Assistant Professor        Indiana University School of Medicine
tel:1(317)630-7960                         http://aurora.regenstrief.org