[pups] Sigma RDQ11-EC, ESDI disk wisdom needed

[Norman Wilson]

I am trying to get a Sigma RQD11-EC ESDI disk controller and Fujitsu
M2261E disk to work in a MicroVAX III, and am stumped.  I am quite
sure the current problem would show up in a Qbus PDP-11 as well, so
I thought I'd ask here.

Those who don't recognize the devices will probably find it boring to
read on, but for the sake of politeness, the RQD11-EC is a four-drive
Qbus ESDI disk controller that speaks MSCP to the host computer, and
the M2261E is a 320MB full-height 5.25-inch ESDI disk drive.  I picked
them both up (actually two of each) just short of someone's dumpster a
couple of years ago, but this is the first time I have tried to use them.
It was believed that they were working when last powered up, which was
several years before they came to me.  They didn't come with documentation.
I hope to get a copy of the controller manual from a geographically-distant
friend, who has already e-mailed me a list of switch settings and some
other key facts.  www.pc-disk.de has a spec-and-jumpers sheet for the
disk.

In a sentence, the trouble is that the controller cannot see the disk.

In more detail:

The RQD11 is configured at address 0160354 (I am testing in a system
that also has an RQDX3 at the standard address which I don't want to
disturb); bootstrap disabled; CPU type LSI-11 (the only other choice is
`none'); interrupts at BR4.  Except the address, these are the same
settings the board had when it was last in use.

There are many disk jumpers.  Among the settings are: drive select 1;
daisy-chain style signal gating; 590 bytes per sector, hard-sectored;
ATTN not set to READY at power-up.  Again these are believed to be the
settings when the drive was last used.

The A (wide) cable runs from the A connector on the disk to J5 (the only
34-pin connector) on the controller.  The drive has a terminator DIP in
place.  The B (narrow) cable runs from the B connector on the disk to
J1 on the controller.  The cables I am using happen to be missing the
keys normally found at the drive end; I have tried all four possible
cable orientations to no avail.

When fed power, the disk spins up and calibrates (the rattling head-dance
I'm familiar with from other Fuji disks of similar vintage).  At no point
have I seen any fault LEDs lit.  The READY LED on the front of the disk
comes on after calibration, and stays on.

The RQD11's CSR responds as it should on the Qbus, and the sequence
that is supposed to open communications with WOMBAT (the firmware command
interpreter) works fine:

  >>>d/p/w 20001f40 20
  >>>d/l 20088008 80000002
  >>>d/w 200000ec ac
  >>>s 400

  RQD11-EC   WOMBAT Version: 2.38
  Drive number:

According to my friend with the manual, before the drive number prompt
the firmware should list all the drives it sees, but I have yet to see
it list anything.  If I give it a drive number between 0 and 7, it reports
`no drv'; any other number yields `Illegal drive number'.

I have tried various experiments, including
- using J3 instead of J1 for the B cable
- different drive-select lines
- changing CHN7 15-16 to `set ATTN at power-up'
each with all four possible cable orientations.

As I say, I'm stumped.  Anybody got any suggestions?  Is there anything
I can do to get better diagnostic information out of either the disk or
the controller?

Thanks much for any advice,

Norman Wilson