29 Apr
2013
29 Apr
'13
6:42 p.m.
At 04:24 PM 4/29/2013, Tony Duell wrote:
Ah.... Are there any recgnisable ICs o nthe controller and the drive? If
it is a Philis/LMS unit, it's likely that the preamplier is a standard
Philips part and that it would be possible to find the RF test point.
On the KRQ50, the two chips closest to the connector for the cab kit
are AMLS2632PC RS422 quad line receivers. There's an AMLS2630PO RS422
quad line driver chip as well that's nearby. The rest of the board is
either standard QBUS glue logic, a bunch of PALs, and an 80186 CPU with
firmware in a couple of EPROMs. Nothing much to build on. I'm going to
try to trace the cab kit connectors to the 2630/2632 when I get a
chance to see what's happening there.
I haven't touched the drive. That's got to be the place to do any
effective testing.
Apparently the cable is a BC18R-06 if anyone has a pointer to
documentation on such things.
-Rick
I would be suprised it it wasn't a straight-through
cable. If it is the
Philips-type interface, the basic signals are the bitstream from the CD
(after a little processing in the drive, it's up to the controller to
extract the parts it wants), and a serial command/status interface to
select a track, etc.
There's 5 twisted pairs feeding each of the two DA15's in the cab kit.
If I had info on the physical interface (which is apparently called
"LMSI" in a lot of places, including Sound Blaster cards that implement
the interface), I could figure out some potential cabling.
I doubt that an AUI cable wil lwork, as that only
has 8 pins used (4 trissted pairs -- transmit, receive, collison and
power), but as I said, I would think that directly conenctign tyhe drive
to the cab kit should work.
That's what I assumed. The AUI cable was the only thing on hand here
that was already built :)
I've got DA15 shells if I could figure out what needed to be hooked up.
Are you sure the drive and controller are working
properly?
No. The drive came with the VAX, which had a dead memory board (now
fixed), an unusable TK50 (replaced) and a dead RD54 (which is still
dead - that's the next thing to try to diagnose).
The controller was bought off of e-pay, so there's no guarantee that
it's functional.