From: dplatt@ntg.com (Dave Platt)
Newsgroups: comp.sys.mac.hardware,comp.sys.mac.programmer
Subject: Re: Trouble using old Rodime drive and VCP Syquest removable
Date: 30 Aug 92 19:23:30 GMT
Organization: New Technologies Group, Inc.  Palo Alto CA

>I am having problems using an old Rodime 100Mb internal drive with a
>new VCP 88Mb removable external drive.  There seem to be some weird
>driver incompatibilities, and some of my files appear to have been
>corrupted.  In particular, the VCP Formatter program, which claims to
>be compatible with everything under the sun, fails when it tries to
>install its driver on my internal drive.  Also, I've had both my internal
>drive and an external cartridge have their partition maps go bad for
>no apparent reason.  Has anyone else had similar problems with an old
>Rodime drive?

The older Rodime drives (e.g. the RO-5000S 5.25" mechanism sold as the
100Plus) have a somewhat quirky SCSI interface.  Their blind I/O has
different timing rules than most other mechanisms, and many third-party
driver packages have difficulty working with these drives.  I found, for
example, that SilverLining was quite unable to work with my RO-5000S
whether in "blind" or "handshake" mode.

On the other hand... Hard Disk Toolkit, from FWB Software, works
perfectly well with my Rodime... and it definitely gives better
throughput (a few percent better) than Rodime's own driver.  The same
driver works beautifully with my Maxtor XT-4380S.

>              Any suggestions on what to do about it?  I've contacted
>VCP, Rodime, and Appolyonics (which wrote the VCP driver) and they're
>all stumped.  (P.S.  I've run the Rodime disk checker program and the
>disk checks out fine.)

I've found the Apollyonics driver package to be quite good at "driving"
most mechanisms, but I haven't tried it with a Rodime.

I've concluded that it's a bad idea to try to use one formatting package
to change or replace the partition table written by another formatting
package.  Although both packages may use "Inside Mac V" formatting
rules, there can be some subtle differences between the partition table
formats, and bad things can happen.

The first thing I'd suggest is that you go back to using the Rodime-
provided formatting software and driver... I've found them to be quite
reliable.  Back up the drive (twice, to two different sets of media),
reformat, reinstall, and restore the files. Check your SCSI cabling and
terminators - make sure that everything is making good contact and that
the cables are not being bent sharply or placed under tension... this
can lead to unreliable operation.

You might also want to consider investing in Hard Disk Toolkit.  I know
for a fact that the driver works well with a Rodime 100-meg drive.  The
"Personal edition" sells for about $49.  The full-up power-user edition
costs about $125 (street price), and includes a "World control" program
which will let you fiddle with the drive's firmware parameters, manually
spare out bad blocks, etc.  I used it to give a complete tuneup to my
Rodime... I erased the "grown" defect list (about a dozen blocks),
reformatted using the "factory-identified" defect list, ran an extensive
surface test, and manually reallocated every block which had any hard or
soft errors (soft errors being those which could be corrected via the
EDAC error-correction logic, or by retrying the read).  The drive has
behaved flawlessly since then.

The HDT software comes with a configurable INIT which will let you
pre-load a driver for your removable disk, so that you'll be able to
mount cartridges on the drive even if there was no cartridge present in
the drive at boot time.
-- 
Dave Platt                                                VOICE: (415) 813-8917
              Domain: dplatt@ntg.com      UUCP: ...netcomsv!ntg!dplatt
 USNAIL: New Technologies Group Inc. 2468 Embarcardero Way, Palo Alto CA 94303