flowers@apple.UUCP (Stephen Flowers) (07/18/87)
Richard Siegel recently reported a problem with HD SC Setup version 1.3
and 1.4 when used with the Macintosh II and the Seagate ST225N disk drive.
I tried to duplicate his problem with no success. None of Apple's
Software Quality Assurance people have reported the problem, and believe
me, they beat the stuffings out of all imaginable configurations of
hardware and software.
I have seen some very early prototype drives which may have a problem with
the Macintosh II's SCSI bus handshaking timeout, but they have not been
shipped as Apple HD 20SC products. If Richard was using an Apple drive and
had this problem (as opposed to an electronic store's ST225N "special",
which could easily be a buggy prototype), then I would appreciate him sending
me mail (include the serial number from the drive case and the disk drive
unit's separate serial number; if you have the tools, the firmware revision
level from the SCSI Inquiry command would be useful, also).
The reason why his disk is apparently getting trashed is a drive that is
somewhat out of spec in its data transfer timing. Version 1.0 of HD SC
Setup formats the drive as 532 bytes/sector, and this changes the controller's
behavior, making the problem less likely to occur. Versions 1.3 and 1.4
will format the disk for 512 bytes/sector on a Macintosh II.
In general, we recommend that customers use the latest versions of our
drivers and utilities. I can understand Richard's wish to use 1.0 if his
drive won't work properly in the 512 byte/sector mode, but I wouldn't
advise everyone to do so.
With regard to the use of Apple's drivers on non-Apple drives, I would like
to offer this: SCSI disks can vary widely in in timing and operation, depending
on the firmware version and hardware version provided. Apple attempts to
put the best quality possible into their hardware and software products,
but cannot take responsibility for those who use Apple software on non-Apple
products. This is not a flame at any particular third-party vendor. I
simply suggest that not all apparently similar drives are best operated with
the same driver.
Steve Flowers, Macintosh System Software group
UUCP: {nsc,dual,sun,voder,ucbvax!mtxinu}!apple!flowers
Disclaimer: I work for Apple Computer, but I am not their spokesman.