Subject: help! shugart 801

From: Joe <[email-masked]>
Date: Mon Jul 21 21:03:00 2003

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

---

From: "Dwight K. Elvey" <[email-masked]>
Date: Tue Jul 22 16:36:00 2003

>From: Joe <[email-masked]>
>
>At 09:26 AM 7/22/03 -0700, you wrote:
>>>From: Joe <[email-masked]>
>>>
>>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
>

Hi Joe
 I missed that about the head not loading. Is the drive getting
a head load signal or is the controller waiting for some status
line from the drive? That would be the first place to look. There
may be slight differences in the gating of these signals at the drive.
 I wouldn't think that the index pulse would cause troubles but
you never know. On either drive, you should see index pulses.
 I'd have to dig out my manual to be able to help any more than that.
Dwight

---

From: Al Kossow <[email-masked]>
Date: Wed Jul 23 19:07:00 2003

> For other drive I have prints but not for the Siemens.

www.spies.com/aek/pdf/siemens/