"sokolov@alpha.CES.CWRU.Edu" "Michael Sokolov" wrote:

>   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

All true - I got almost everything wrong. The RRD42 is single speed and its 
specs do not look too different from those of the RRD40. I was confused by the 
fact that until recently I used a CDU-561 as my home PCs CDROM *and that was 
double speed). In addition, when I replaced an RRD40 by an RRD42 a few months 
ago, the improvement was dramatic; based on the specs, I cannot explain that!

>   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.

Very probably true (although I've never tried it) - the RRD50 tabletop box is 
big enough that you should be able to find room inside it for the adapter!

>   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?

If the light on the front does not light briefly on power-up, then it sounds 
very much like a dead drive. It may be that all that is wrong is the internal 
PSU: you should be able to open the box up and verify that the +5V and/or +12V 
feed to the drive are good - alternatively remove the RRD42 from its casing and 
temporarily hook it up as an internal PC drive to see if it powers up at all. If 
it does then you need a new internal PSU (or perhaps a new case with PSU would 
be cheaper?).

Antonio

Antonio Carlini                            Mail: carlini@marvin.enet.dec.com
DECnet-Plus for OpenVMS Engineering
Digital Equipment Corporation              Worton Grange, Reading, England