RX02 Difficulties

[Aaron Jackson]

Hi everyone,

I originally posted this on VCFed (which was new to me) but the
moderation queue has had me waiting for about 3 days, so I thought I'd
ask here as well, the usual of gurus. :)

I was recently sent an RXV21 controller so I could test out my RX02
drive. When I power up the PDP-11 or reset the machine I get the nice
clunking sound which I have been told is normal. I expect I wouldn't
hear this if the ribbon cable was in the wrong way.

To test, I tried to use VTserver to dump the contents of a disk, but it
immediately threw an error. I soon realised there are two DIP switches
on the logic board of the RX02 drive which had to be adjusted to work
with the RXV21. So, I had some progress. Output of VTserver almost
looked promising but then it hangs, as below:

]] Tape record n from device xx is written as xx(0,0,n)
]] Disk drive xx is written as xx(0,0,0)
]]
]] Enter name of input record/device: rx(0,0,0)
]] Enter name of output record/device: vt(0,0,1)
]]
]] Opened copy.out read-write
]]

So, following some advice I booted via TU58em into XXDP and ran the
diagnostics:

]] DR>STA
]]
]] CHANGE HW (L)  ? N
]]
]] CHANGE SW (L)  ? N
]]
]] CZRXFB0 SYS FTL ERR  00040 ON UNIT 00 TST 011 SUB 000 PC: 003476
]]  CSR BITS - LGC TST
]]   AC LOW FATAL ERROR
]]       REG ACTUAL=000000
]]       REG EXPECT=000000
]]
]]   POSSIBLE FAILING "FRU'S":
]]             INTERFACE - M8029
]]
]]   UNIT#0 RXCSR=000000 RXESR=000000 CMD=000000 ->
]]  ->NO PWR, CABLED BACKWARDS, STRAPPED RX01, PDP-8
]]  DROP UNIT#0 FROM TEST
]]
]] PASS ABRTD THS UNIT
]] CZRXFB0 SYS FTL ERR  00040 ON UNIT 01 TST 011 SUB 000 PC: 003476
]]  CSR BITS - LGC TST
]]   AC LOW FATAL ERROR
]]       REG ACTUAL=000000
]]       REG EXPECT=000000
]]
]]   POSSIBLE FAILING "FRU'S":
]]             INTERFACE - M8029
]]
]]   UNIT#1 RXCSR=000000 RXESR=000000 CMD=000000 ->
]]  ->NO PWR, CABLED BACKWARDS, STRAPPED RX01, PDP-8
]]  DROP UNIT#1 FROM TEST
]]
]] PASS ABRTD THS UNIT
]] CZRXFB0 EOP    1
]]     2 TOTAL ERRS

So, the possible errors according to XXDP:

- Bad power - I get 25v, 5v and -5v. The motors are spinning, not
  convinced it is this?

- Cable backwards - I don't think I'd be hearing that clunk.

- Strapped RX01 - I don't know what this means

- PDP8 - eh?

If anyone has any suggestions it would be great to hear them.

Thanks,
Aaron.