doesn't load with Alps but does with Newtronic

rmzalbar

New Member
Oct 12, 2019
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This is an odd one: X2 (physical boxed copy) is unreadable on BOTH of my Alps-mechanism 1541 drives. Will not load the directory or any files - they attempt to read for a second, then immediately stops with a blinking light and reports a read error. However, my other 3 drives, which are all Newtronics-type, read the disk perfectly.

None of my other disks, commercial or otherwise, have any problems on these Alps drives. It does not appear to be an alignment issue - alignment issues typically manifest as retries involving sending the head home (chatter) a few times. Nothing like that happening here.

I made a DOS copy of the disk to a blank floppy using one of the Newtronics drives, and the copy works fine on both Alps drives. Certainly, I can just recopy to the original disk to correct the issue, so this is not a support request - it's just piqued my interest, and I would like to satisfy my curiosity as there should not be any functional difference between these drive units, yet there appears to be one.

I'm thinking there must be some difference with the Alps drives, and a particular way the disk is formatted, that are overlapping in some way. Do you happen to have any insight? I recall from the video that 1571 drives were being used to make the copies.

Thank you, -Rob
 

rmzalbar

New Member
Oct 12, 2019
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2
3
Nevermind, I discovered the issue. The disk isn't spinning. There was glue intrusion where the rear flap of the jacket is sealed, that seeped inside the jacket during manufacture. It took up space and didn't allow the media to slide in the rearward direction quite far enough, so the disk jams in its jacket when clamped into the drive.

The Newtronics gate mechanism doesn't pin the jacket quite so far into the drive, so it had clearance to slip back a bit and accommodate the disk. I've already made a copy and moved the very nice label over to the new disk.
 
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