Re: WTD: tandon 603s or 602s

From: B. Degnan (
Date: 2006-07-02 23:31:07

I just opened up the drive and found J14.  As I was about to cut J14 I 
decided that I am ready yet to make this change  ... I would rather try to 
find a 6 head drive first.  I am patient and I would like to get the full 
7.5 MB's if I can.  I am not 100% sure that my ST-225 works, and then I 
would have circumcised the drive controller for no reason.  :-)

A while back I tried using a Miniscribe 3650 that I was given from a 
reliable source, who described it as working.  I read someplace that this 
drive was used to replace a tandon 603s successfully.  This drive has 6 
heads and 809 cylinders.  When I format it starts out OK (you can hear the 
click click click for about a 1/2 hour, and then it just spins with no 
further format activity.  I am aware that it can take quite a while to 
format a d9090 drive, but after 5 hours I pulled the plug.  Perhaps the 
drive had a defect.  Is there a header command that stops the formatting 
process at a pre-defined number of cylinders?

Do I understand correctly that the ST-225 is a straight substitute for the 
Tandon 602s D9060 "out of the box", and that no drive controller changes 
are needed?

I will see if I can dig up a working 6-head ST 251.  I may also be able to 
get a Tandon TM603SE.

One last question...I use this command to check the drive


I get the response code 73 and the DOS version.  Is there anything else I 
can do to make sure that the controllers are working?  Maybe I have been 
barking up the wrong tree.

Bill D

At 05:49 PM 7/2/2006 +1200, you wrote:
>On 7/2/06, Anders Carlsson <> wrote:
>>Bill Degnan wrote:
>> > Theoretically you do not have to do anything to the drive if you swap
>> > a 603s for a 602s.  If you use a 602s, you in effect convert a d9090
>> > into a d9060, and the capacity is reduced to 5MB.
>The only difference between a D9060 and D9090 is the specific drive
>mechanism installed, the position of a jumper (see below), and the
>sticker on the outside.  One of the drives I have at home was sold to
>me for a pittance because it "wouldn't format" - someone had replaced
>the TM603S with a TM602S and failed to move the jumper.  Quick fix.
>>The ftp index on this page says:
>>"The jumper J14 on the DOS board is open in the D9060, and closed in
>>   the D9090 to select a 4-head vs. 6-head drive."
>>Maybe that's what you are missing if you tried a 4-head ST-225 with a
>>D9090 drive?
>That will certainly fail to format.  Try an ST-251 for a 6-head
>drive... those are almost as common as the ST-225 (they shipped
>standard with the original IBM PC-AT).  Of course, having a 5MB PET
>hard disk isn't so bad, especially since they don't have

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