Dear Antonio,
   
   You wrote:
> Both the RRD40 and RRD50 are very slow: a dual speed RRD42
> is a big improvement!
   RRD42 is single-speed. (Believe me, I know. RRD42 is really Sony CDU-541
with different firmware, and the only difference is probably in the word
"DEC". CDU-541 is a very well-known 1X CD-ROM drive. Heck, everyone on our
campus who has ever worked with this old stuff knows that it's 1X). Thus
the only way RRD50 and RRD40 can be slower is if they were "1/2 X", but I
don't think they were. Most probably they were 1X too, and thus RRD42 has
the same speed. But it's still an improvement, since it no longer needs an
adapter board to be SCSI, and thus can be put in a half-height bay where
there is no space for the adapter board. Plus it uses standard caddies.
> [...] the second one (and
> the first to have an optional SCSI interface) was the RRD40 [...]
   If RRD50 and RRD40 has the same native interface (which is certainly the
case if RRD40 is controlled by KRQ50 as you say), then one can create a
SCSI RRD50 by connecting an RRD50 through the adapter board that DEC used
with RRD40.
   BTW, I have an RRD42 which I can't get to work. Long Wang, the guy who
was the system manager before I had laid my hands on that drive, says that
it worked for him. At the end of this posting, I'm attaching excerpts from
my letters to him describing the problem. Do you have a clue as to what's
wrong?
   
   Sincerely,
   Michael Sokolov
   Phone: 440-449-0299
   ARPA Internet SMTP mail: sokolov@alpha.ces.cwru.edu
   
   Enclosures: excerpts from my letters to Long Wang describing the RRD42
problem. The first one:
   
   Dear Long,
   
   I'm sorry to bother you again with CWRU stuff, but I need your help,
this time with a CD-ROM drive. In your former office, I have found a DEC
RRD42, a 1X SCSI-1 CD-ROM drive. It was external (really a standard 5.25"
half-height device in a SCSI case). I started playing with it, and I have
discovered that the drive inside apparently doesn't work, while the power
supply and other stuff in the SCSI case does. I wonder if you can tell me
whether the drive is really at fault or I'm doing something wrong. I had no
problem with another Sony drive, though. (This drive was really made by
Sony, even though it says "DEC" on it.)
   [...]
   
   The second one:
   
   Dear Long,
   
   The "other" Sony CD-ROM drive hasn't come from CES, but has been given
to me by a student, so it's understandable that you are unaware of it. It's
really Sony CDU-561, but it has come from a Compaq server, and apparently
Compaq has messed with its firmware, since when I connect it to my IBM PC
AT-compatible, Adaptec software identifies it as Compaq. The drive that I
have found in your former office says "DEC RRD42" on it, but really it's
Sony CDU-541. This one has definitely been skunked by DEC, since when I
opened up its cover to look at the control board, I have seen DEC's
copyright on the firmware EPROM chip. CDU-541 is 1X SCSI-1 and CDU-561 is
2X SCSI-2. Apart from this, they are very similar. Both use caddies.
Actually, I like CD-ROM drives with caddies better than those with cup
holders.
   But I'm really surprised that you haven't had any problems with the 1X
drive. First I had tested the 2X drive, and everything worked perfectly on
the first attempt. Since external SCSI devices are easier to fiddle with
than internal ones, I already had my SCSI card (AHA-1520A) installed with
the on-board terminators in place and no internal devices connected. At
that time I already had the external SCSI case from the 1X drive
disassembled, so I just connected the 2X drive to the case and then
connected the latter to my SCSI card with an external cable. Upon booting
up, the ASPI manager (since AHA-1520A is based on the AIC-6360 chip, it's
ASPI2DOS.SYS) does a scan of the SCSI bus and lists all the devices found.
In this case, it had immediately detected the 2X CD-ROM drive at SCSI ID 6
(that's when I have learned that its firmware says "COMPAQ"). I didn't even
have to load the SCSI CD-ROM driver (ASPICD.SYS) to see that the drive is
there, but when I did so, I had confirmed that it's not only there but it
even reads CDs!
   With the 1X drive, I was less lucky. I had connected it in exactly the
same way as the 2X drive, but this time the ASPI manager didn't find it at
boot time. When I tried to load the SCSI CD-ROM driver with the correct
SCSI ID specified on the command line, it had immediately bailed out, so
apparently it doesn't even try talking to the drive if the ASPI manager
hasn't found it. First I had thought that I had done something wrong.
Usually when there is a configuration problem (jumpers, ID, termination,
software, etc.) the interface doesn't work, but the drive mechanics does.
To test whether this is the case, I had tried disconnecting the drive from
the SCSI bus. I had loaded a caddy and tried pressing the eject button.
Guess what, the drive didn't do a thing! I had to use a paper clip to make
that sucker give me my caddy back. In general the drive appeared completely
dead, as if it were not getting power (I HAD checked the power connection).
And by the way, the 2X drive was lighting its LED shortly upon power-up and
the 1X one wasn't, further confirming the theory that something is
seriously wrong.
   You write that you have used that drive on PCs. How would you do that
with Adaptec software (assuming that's what you have used)? Is there some
magic that I have forgotten to do?
   [...]