[comp.sys.atari.st] Cumana External Drive Problem : Or is it?

lezo@syma.sussex.ac.uk (Lez Oxley) (07/26/89)

I have just noticed what I think are problems with my Cumana CSA 354 
1 Meg Disk Drive which I use as external drive B. It is only 3 months
old and is connected to a 'standard' 3 year-old 1040ST with 'old' TOS in
rom. The problem occurs intermittently in all screen resolutions. Can
anyone offer any help/advice which does not involve taking things to
bits! The symptoms are as follows:

1. Used as a drive for reading only the drive seems to be OK.

2. Random seek tests and speed tests seem to be OK. 

3. When used for writing to, single one-off file transfers seem to be OK.
   (eg. saving a WP document or program source very 20 minutes or so.) 
 
4. When used for writing to, involving disk to disk copying (Drive A: to
   Drive B:) sometimes the internal drive can't read the disk so
   produced and neither can any other Atari Disk Drive.  Sometimes the
   Cumana drive itself can not consistently read its own disk, ie.
   sometimes it refuses to read what it has written, ten minutes later,
   however, it may read it (after rebooting disk swapping etc).

5. When used for writing to, by copying (say) 30 files from drive A:
   some of the 30 files seem to get corrupted. The 'directory' entries
   look OK - files sizes OK, etc. but when you list an ASCII file (eg)
   you sometimes get garbage in the file instead on the real data.
   Program files are corrupted in a similiar way  and either they time
   bomb out or chunks of code don't work. Unlike 4. the Cumana drive is
   never able read the corruption.

6. I have used George Woodside's VKILLER to check for a virus and
   nothing's shown up. (I get the problem when I boot up from a wide
   range of disks.)

7. The same problem occurs on different media - cheap disks, SONY disks,
   Memorex disks, Verbatim, . . .
	  
8. I am not using lots of folders - no more than 10 in a session.


Has anyone got any ideas as to what may be going wrong - I always
thought  that TOS verified everything it wrote to a disk (an annoyance
to some people I know)?

Are there any nifty disk checking utilities out there? If so can someone
mail me a disk checker or even a byte-by-byte file comparision program
so that I can reverify files written on the Cumana?

Any help will be gratefully received. Sorry to have gone on at such
length but I felt I had to supply as much information on the problem as
possible - this is my first posting to the net.
 
(For all I know the drive may have been faulty at birth or got crunched
slightly coping with all that horrible copy protection which makes your
disk drive sound more like a coffee grinder.)

 	



-- 
Lez Oxley, Administration, University of Sussex, Brighton, BN1 9RH, UK
Tel: +44 273 606755 x3808 Fax: +44 273 678335 JANET: lezo@uk.ac.sussex.syma
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