help! shugart 801

From: Joe <rigdonj_at_cfl.rr.com>
Date: Tue Jul 22 16:02:00 2003

At 09:26 AM 7/22/03 -0700, you wrote:
>>From: Joe <rigdonj_at_cfl.rr.com>
>>
>> I have several systems that use Shugart 800-1 SS 8" disk drives. I've
>>got several defective drives plus I've been wanting some spares. Last week
>>I picked up 10 Shugart model 801 SS drives. Today I tried to use them on
>>the same systems but I can't make them work. I've set all the jumpers and
>>straps exactly the same as in the 800-1 drives but the 801s aren't working.
>>The system knows the drive is there and detects the disk being in place and
>>rotating and that the drive door closed but the drive never gets the head
>>load signal. I'm using the same system, cables, power supply, etc with both
>>drives so the only difference is the drives themselves. I've tried a couple
>>of 801s and gotten exactly the same results with all of them so I don't
>>think that it due to a drive failure. Anybody have any experience with
>>these or have a good idea of what's wrong?
>>
>> Joe
>>
>
>
>Hi Joe
> You do know that some of the drives have data separators.
>I forget which numbers have this and which don't. I don't recall
>if the 800-1's had them or not. If you are using these for
>M2FM, is seems that I remember that the bandwidth was slightly
>increase on these drives. As I recall, there was a capacitor
>change in the pre-amps.
> Those are the only things I can think of.
>Dwight
>

   You may be right but the head isn't even loading so I'm not even getting
that far. I have a Shugart 800/801 manual but it's vague about the
differences between the two. But IIRC the 801 is designed to handle hard
sectored disk and the 800 doesn't. I'm wondering if the index pulse
detection circuit is different and may be causing a not ready condition or
something similar. (Yes I know I can check it with a logic probe but I
didn't have one where the machines are located so I havne't done that yet.)

     Joe
Received on Tue Jul 22 2003 - 16:02:00 BST