ESDI Magneto Optical Drive

Curtis H. Wilbar Jr. rescue at
Mon Aug 20 22:25:09 CDT 2007

Jerome H. Fine wrote:
> >Mr Ian Primus wrote:
>> I was searching on eBay for ESDI stuff, and came
>> across an ESDI MO drive. Now, this was listed by one
>> ...
>> So, did they even make this drive in ESDI?
> Jerome Fine replies:
> The first SCSI MO drive I ever used was from Sony.
> The SMO S-501 consisted of two parts (this is from
> memory and it was over 15 years ago - so it is likely
> unreliable):
> (a) A C-501 PCB about the size of a 5 1/4" drive which
> had a 50 pin SCSI header interface for the host adapter
> and a 34 pin / 20 pin (2 of these if I remember correctly)
> header interface for each of the 2 supported drives.  This
> board was called a controller and was completely separate
> from the drives
> (b) A D-501 5 1/4" drive which I was told had a MODIFIED
> ESDI interface and used standard 34 pin / 20 pin edge
> connectors.  Exactly what the word modified meant specifically
> was never made clear, however, Sony made it VERY clear that
> the C-501 controller PCB was required to interface the D-501
> drive to a SCSI host adapter and any warranty on the D-501
> drive seemed to be dependent on using the C-501 controller
> as an interface.
> ...
> Jerome Fine
Heh.... someone really knows there old Sony MO...

Funny enough... I ran one of these combos.... I aquired a drive
w/o controller... (cheap thankfully)... later on I aquired a complete
enclosure/controller/drive.  Turns out the drive on the complete one
was bad... (Wow... I had a spare ! (completely accidentally of course...
never would have gotten the bare drive in the frist place if I'd
have known :-) ).

Well, needless to say, even later I aquired another enclosure that had
two of those drives in it (and interestingly two bridge controllers).

at least one part was bad in there.

Suffice to say I think I have a whole single drive unit with bridge
and a second drive bare... and I think 2 working bridge controllers
here.  (now the question of precisely where here... well,
that's more complicated :-) ).

I used 2 discs to backup some stuff too....  (abt 10 yrs ago).
When I moved to the house I'm in now, one of those discs I discovered
unreadable... but the other was fine.  This year I discovered the
2nd disc now unreadable....  I even tried a SCSI (I have an SMO-E501)
drive...  no go.

I also have a number of discs for these.

After my experience, I don't trust them anymore.  I think they are
environmentally sensitive... and I'm thinking that they probably got
too warm or something ?  dunno...

If anyone is interested... make offers on parts, whole units, discs, etc...
I have no plans to use them at this point. 

I did like the unit when I had it up and running....

-- Curt

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