HP 9895A 8'' Floppy Drive - Problem

[Paul Berger (Canada)]

(12-18-2019 12:18 PM)Michael Fehlhammer Wrote:  Hello Paul,

thank you for these good news, I would never have thought that there could be some compatibility among these old 8 inch drives.

But which details I will have to pay attention to?

First, I need a double sided drive of course (I saw 1S drives relatively often).

And then: For example, my 9895A is configured for 230V / 50 Hz. Now I see floppy drives offered on Ebay which are labelled "60Hz 115V", what I don't understand; I thought 24V DC are supplied to the drive, transformation is done outside in the 9895A controller?

And what about the eject mechanism? I found that one on Ebay Europe:
8 inch Floppy.
Apart from the high price: It is a full-size drive, but looks very different on the front side, and I doubt that it can be modified to use the 9895A front door?
I guess you don't use the 9895A housing any more, just the electronics.
Unfortunately, as a collector I am not only interested in functionality ...

The 60Hz 115V would be for the motor, most if not all of the original full height 8" drives use an AC motor to turn the diskette and even if you where to provide a 220 to 115 transformer the difference in line frequency would mean the motor would run at the wrong speed which is why there are different pulleys for 50Hz and 60Hz. The half high 8" drives I have use a 24V DC motor to turn the diskette.

You are right I don't think you could make that Siemens drive look like a Shugart (I think the originals are Shugart) If you where to get a replacement Shugart, even if it was a 115V 60Hz you could swap the motor and pulley from you current drive.

Did you swap that drive electronics between the two drives when troubleshooting? Head failures are pretty rare, and since they typically have a glass surface it take a lot of use to wear down the heads. Another issue is alignment, if the drive gets a bit out of alignment, it could read diskettes created on it, but would fail to read diskettes from another drive.

I have never had a 9895 shell only the controller board, and probably an early one at that, the ROMs on the board are PROMs with hand written numbers on them.

Paul.