Re: UPDATE #2: Apple IIgs / Iomega Zip Drive Problems

[Rubywand <rubywand@swbell.net>]

"Douglas E. Morris" writes ...
> 
> Well,
> 
> I decided that mabey if I deleted all the partitions on the disk that would
> help.  So I hooked it up to a linux box, wiped the partition table, and put
> it back on the IIgs system.  Exect same problems I was getting before with
> the exception that the GS is no longer identifying the zip disk as MS-DOS.
> 
 ....

     A new Zip disk formatted for PC is formatted okay. As you suggested
earlier, it needs to be partitioned (but not formatted).  Partitioning is
fairly speedy; formatting takes around 10 minutes. (I discovered that after
wasting time formatting a few disks just after getting a Zip drive.)

     Since you are using an Apple SCSI card, something you probably should
check for is a modification to supply termination power. There is some
information about the mod (for the high-speed and earlier card) in the FAQs at
http://home.swbell.net/rubywand/Csa2HDNSCSI.html#018 . Some Apple SCSI cards
you buy will already have this mod and some will not.

     The "Termination" setting on the Zip drive relates to having a termination
load at the end of the SCSI chain. Some device on the chain is supposed to
supply termination Power. Usually, this job falls to the SCSI interface card.
(The Zip drive and most other SCSI devices can not supply termination power.)

     A Zip drive may seem to work okay without termination voltage being
present; but, operation may not be as reliable as it should be.


     Probably, the Zip disk you experimented with will need to be reformatted.
If you have access to a PC with a suitable Zip drive, you can reformat it
there. (I guess Apple Disk Utilities should be able to do it on a IIgs. By the
way, ADU is not a very user-friendly utility. Making it do what you want takes
some fiddling and luck.)

     With System 6.0.1 going, another option is to let GS System format the
experimental Zip disk as a single large partition HFS volume. This should take
care of formatting. Since it would not be a ProDOS disk, you would not be able
to run most programs from the disk or boot from it; but, you would have a big
chuck of space to store files.

     Something that may help improve SCSI operation is to power ON the Zip
drive and insert a disk before powering ON the computer. Also, it may help to
hold down the Control and Reset keys, turn ON the computer, and wait a couple
seconds before releasing the keys. (The idea is to give the SCSI interface a
brief time to stabilize before handing things over to the IIgs startup
sequence.


Rubywand