CMDNESPG@UIAMVS.BITNET (Steven Nelson) (02/26/88)
Feb 25, 1988
Judging from error notes from a couple of nodes, I'm not
sure this post made it to all the networks. Please excuse the
duplication.
Feb. 21, 1988
Does anyone have any experience or suggestions for using Central
Point's universal disk controller with Apple-Mac 400K disk drives
on an Apple //e?
I'm having a great deal of trouble. I've tried 3 controller boards,
and over a dozen different drives. Chinon 800k and Mac 800 external
drives work fine, 400k drives cause many write errors and trashed
blocks under Prodos (v1.4). All 400k drives seem to read Ok, but
a disk copy (using copyiiplus v7.4) gives 1 or more write errors
(always at seemingly random blocks) and ususally cause even more
verify errors than write errors. I noticed a tendency of most drives
to cause a verify error in block 9 after formatting, and 3 or 4 drives
couldn't write to block 6 and caused a format failure because it
couldn't finish writing the vtoc blocks. All 400k drives work fine
on a MacSE, but I don't have any program to test them on a Mac per se.
I called the company, but couldn't get a definite answer. "We
don't recommend 400k drives. Get a 800k drive." was the consistent
response. One man said he personally had not had any problems in
house with 400k drives - but he also said 400k drives could not
reliably read 400k disks formatted on Mac or GS drives. He also said I
shouldn't use disk copy or file copy programs with a 400k drive -
only load and save files from within Appleworks, etc. ProDOS has
random errors with copying! BAH HUMBUG!, thought I!!! ProDOS would
have the same errors writing from Appleworks as from any copy program!
Anyway, pressing him for an answer as to whether I should keep testing
drives, he emphasized "We don't recommend 400k drives".
I have tested these cards on II+, //e, and two enhanced //e's with
about similar failure rates. Note failures are essentially random.
I always get one or more, but rarely same blocks from test to test.
As noted block 9 is a real problem, most other blocks are in the
range $1B0 to $2D0, or so. No particular card/drive combination
seems to work much better, than another combination.
Now, I have access to a pool of used 400k drives (cheap, $60 @).
Should I keep trying, or give up?
Has anyone gotten 400k drives to work with a UDC?
Thanks for any insights.
Steven E. Nelson / Univ. of Iowa
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