ted@polyof.poly.edu (Theodore S. Kapela, staff) (10/17/90)
I have a Data Technology Corporation 3280A SCSI host adapter w/floppy
controller. I have been trying to use it with my 5 1/4" and 3 1/2"
drives (both high density). When I first boot the machine and try to
read a floppy, everything seems OK. BUT, when I change the floppy and
try to do a dir or chkdsk, The drive does not really read the floppy.
I turns the drive and access light on, but does not appear to read
anything. I get the same info (eg: directory listing) that I just had
for the floppy that was in the drive last. ALSO, I can not swith to
another density media after first reading a disk. If I read a high
density disk, that is all I can use the drive for. If I read a
standard (double) density disk, that is all I can read afterwards.
If I try to format a disk, though, I can format either density just
fine at any time. I can then only read that density afterwards.
I tried using DOS's driver.sys to make another "virtual" drive.
I used a: for the high density 5 1/4" drive and e: for the double
density 5 1/4" drive. They are both physically the same drive,
but I told DOS that their parameters are different. Format recognizes
the parameters and formats the disk appropriate for the drive, but the
rest of DOS doesn't care. I can read either density in either drive,
but then I have the same problem as above, only for both drives (if I
read a 1.2M disk in a:, that is all I can read in i: also.)
The problem does not pertain strictly to DOS. It happens in applications
also (possibly because they use DOS calls for disk access).
The drives worked fine with another controller. I had no problems
then.
If anybody else has had this problem or has any clue how to remedy the
situation, I would greatly appreciate a reply.
--
...............................................................................
Theodore S. Kapela (516) 755-4299 [Voice, Days]
ted@polyof.poly.edu (516) 473-7746 [FAX]
"Another brilliant mind corrupted by education"poffen@sj.ate.slb.com (Russ Poffenberger) (10/18/90)
In article <1990Oct17.165757.4274@polyof.poly.edu> ted@polyof.poly.edu (Theodore S. Kapela, staff) writes: >I have a Data Technology Corporation 3280A SCSI host adapter w/floppy >controller. I have been trying to use it with my 5 1/4" and 3 1/2" >drives (both high density). When I first boot the machine and try to >read a floppy, everything seems OK. BUT, when I change the floppy and >try to do a dir or chkdsk, The drive does not really read the floppy. >I turns the drive and access light on, but does not appear to read >anything. I get the same info (eg: directory listing) that I just had >for the floppy that was in the drive last. ALSO, I can not swith to >another density media after first reading a disk. If I read a high >density disk, that is all I can use the drive for. If I read a >standard (double) density disk, that is all I can read afterwards. The AT class machines introduced a tehcnique using a signal line on the floppy drive to indicate that the drive door was opened. This line is supposed to be a clue to DOS to re-read the disk since it may have been changed. Simple commands like "dir" cahce the information in memory, and don't re-read the disk for another "dir" operation if the drive door hasn't been opened. It is possible that either the drive itself or the controller do not support this feature. > >If I try to format a disk, though, I can format either density just >fine at any time. I can then only read that density afterwards. > >I tried using DOS's driver.sys to make another "virtual" drive. >I used a: for the high density 5 1/4" drive and e: for the double >density 5 1/4" drive. They are both physically the same drive, >but I told DOS that their parameters are different. Format recognizes >the parameters and formats the disk appropriate for the drive, but the >rest of DOS doesn't care. I can read either density in either drive, >but then I have the same problem as above, only for both drives (if I >read a 1.2M disk in a:, that is all I can read in i: also.) > >The problem does not pertain strictly to DOS. It happens in applications >also (possibly because they use DOS calls for disk access). > >The drives worked fine with another controller. I had no problems >then. > >If anybody else has had this problem or has any clue how to remedy the >situation, I would greatly appreciate a reply. Either it is a bad controller, or it simply doesn't support the door opened feature. My suggestion is to get an Adaptec AHA1542 controller instead. :-| Russ Poffenberger DOMAIN: poffen@sj.ate.slb.com Schlumberger Technologies UUCP: {uunet,decwrl,amdahl}!sjsca4!poffen 1601 Technology Drive CIS: 72401,276 San Jose, Ca. 95110 (408)437-5254
roger@marque.mu.edu (Roger Abrahams) (10/21/90)
I missed the original posting on this (not unusual). I also have this card and have both 5-14 and 3-1/2 drives on it. First of all, you can always try a ^C before doing a directory on the drive, this should tell dos to reset the drive change flag. This is actually a hold over from CPM, as this is how you told CPM that a new disk was inserted. The basic problem is probably that SW1 switch 7 is set wrong. This is the "dual-speed supported switch". The card comes from the factory with this option disabled. SW1 is the switch directly below the DTC403 floppy controller. The switch numbers are 1 at the top to 10 at the bottom. Simply reverse #7. There is also another problem, particularly with some 3-1/2 drives as they have a jumper for the drive change signal. This is to provide compatability with older PC's as opposed to AT's. This could ALSO be set wrong. Since I have this exact set-up, I can assure you it works properly. There is no need to change to another controller. Mine works quite well, providing a transfer rate in excess of 800K on a 20mhz 386 machine. - Roger