Weird 5.25 Apple Drive issue

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Weird 5.25 Apple Drive issue

Hi

strange issue with a Apple 5.25 drive.

 

 Testing on Apple-Cilian the drive passes all tests including read / write / format and disk speed calibration.     

As the 2nd drive I can perform all functions.   However as a boot drive it will not cycle through a normal boot and boot up a disk.   

I've used 2 different Apple computers, I've used two different controller cards.   Still this drive is acting up.  When I replace with a different drive that drove acts as it should

 

any idea on what I should check next?  

 

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If the problem is booting

That suggests a problem with the P5 prom which holds the boot code. Try replacing the P5 with a known good one.

The P5 is on the Interface card. Do you have a spare interface card you can try?

Can the interface card boot with another drive?

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tolderlund wrote:That
tolderlund wrote:

That suggests a problem with the P5 prom which holds the boot code. Try replacing the P5 with a known good one.

The P5 is on the Interface card. Do you have a spare interface card you can try?

Can the interface card boot with another drive?

 

This symptom has nothing to do with the P5 PROM.  It's clearly a disk drive issue.

I think maybe it is alignment related, especially if it passes all the Apple Cilling tests - which are read-write tests.

 

The following test is what I suggest:

 

Connect your drives with a known-good drive as Drive 1 and the suspect drive as Drive 2.

Boot a DOS 3.3 disk like the Apple DOS System Master using your known-good drive as Drive 1

Insert a blank disk into Drive 2 - the suspect drive.

From the ] prompt format Drive 2 with the command INIT HELLO,D2

 

It should format the disk in Drive 2.  Then power down the system, swap the two disk drives around so that the suspect drive is Drive 1.

Boot the disk you just formatted.  I'll bet that it boots properly.  If it does, then the alignment is different between the two drives.

 

If that is the case, then you will need to adjust your alignment against a known-good diskette.  A few non-copy protected commercially produced diskettes are best for this purpose.

You should get a copy and learn to use APTEST, which has the only passable drive alignment utility that is useable without special tools or analysis equipment.

 

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baldrick wrote:
tolderlund wrote:

That suggests a problem with the P5 prom which holds the boot code. Try replacing the P5 with a known good one.

The P5 is on the Interface card. Do you have a spare interface card you can try?

Can the interface card boot with another drive?

 

This symptom has nothing to do with the P5 PROM.  It's clearl

@baldrick

 

Thank y0u - that was the problem and as you suggested the APTEST software allowed me to fix the issue !  Thanks!

 

Michael

 

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