Teac FD-235F Floppy Drive Index Timing

[sean_sk]

Hi all,

I'm a bit of a doofus. I was just cleaning my TEAC FD-235F drive from an A1200 and I decided to take the circular back plate off the spindle to check the condition of the bearing and didn't take notice of the orientation of the plate vs the top part of the spindle that engages with the floppy disk.

The plate as a single hole plus a little magnet which passes a sensor on the circuit board which I assume is for index timing perhaps(?). Does that plate have to be oriented in a particular way for correct indexing of the disk or does it not matteer? I've included a picture.

Tried looking for a service manual but couldn't find one. Thanks in advance.

[Keir]

There'll be a notch on the spindle which engages with the index hole on the diskette's central metal hub. The magnet will probably want to be aligned with that.

[sean_sk]

Will give it a go. Thanks for that.

EDIT: Yeah seems to be working fine. Disks are formatting fine and I'm verifying them on another floppy drive with no issues, and disks are loading fine as well. Thank you very much.

[Keir]

AmigaDOS doesn't care about index alignment anyway, nor do most games. So it's pretty non critical.

[sean_sk]

Yep fair enough. That's good to know.

I didn't realize but I had another one of those drives which was inside an external unit and I noticed that when the magnet was aligned with the sensor, the index notch was aligned between the centre spindle and the read/write head so I re-aligned my internal the same way and it still worked.

So as you say, it seems it doesn't really matter. It seemed to work fine both ways.

EDIT: After having checked a couple of other Amiga drives, including a Sony, I can confirm that the index notch is definitely aligned between the center spindle and read head when magnet on the circuit board side is aligned with the sensor. So that's the way I've done it with the Teac drive.

[hooverphonique]

Originally Posted by kaffer

AmigaDOS doesn't care about index alignment anyway, nor do most games. So it's pretty non critical.

this.. so even if it seems to work, you may come across sw in the future that doesn't work if the index is misaligned..

[demolition]

As mentioned, AmigaDOS won't care about it as well as most cracked games, but some original games / copy protections may rely on it and refuse to load if the absolute alignment is off.

How accurate does the alignment have to be? Can one just eyeball it? I did the same as Op to my F-354E and now am trying to re-align it? Are there any docs out there? Google wasn't my friend in this regard..