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Oh dear, I'm running out of ideas in how to get OS65D working and/or confirm wether this disk works. I just feel to be going around in circles now. One thing I may try is taking the data separator board off the drive and try plugging it into my System 80 (TRS80 clone from Australia and NZ) as this i...

The new motor arrived today. This was a motor from a newer MPI drive so Installing it was simple and there was no need to cut wires and solder. Everything is nice and smooth now, but unfortunately that hasn't changed much in the operation of the unit. Still seems to dump an awful lot of 00's and my ...

I tested the track_00 line today with it plugged into the C42P and running the disk dump utility. At the 74LS38 (E3) pin 6 (or J1-26, it's the same thing) when the head is over track 0 the pin is low, if the head moved to any other track the output had no reading using the logic probe. The pin seems...

I found some much clearer MPI 51 manuals and schematics here: http://z80cpu.eu/mirrors/oldcomputers.dyndns.org/rechner/tandy/docs_from_www.trs-80.com/manuals/hardware/ This evening I traced the track_00 signal back from the track_00 LED sensor through the logic and back to the J1 floppy connector pi...

Quick update. I tested the track 0 sensing line at J4-12. When the head is at track 0 the line is low, at any other position the line becomes high so it seems that the sensing is indeed working at this point. Trying to take a reading from pin J1-26 which is the floppy cable connector track 00 line, ...

I thought I'd start a new topic on this rather than wrap it into my previous OSI 4P repair thread, here: http://osiweb.org/osiforum/viewtopic.php?f=3&t=49 I will start by listing all the things I have done so far: - Replace main spindle bearings - Pull main motor (not the stepper motor) apart to see...

Just a quick update on the C24P. I was messing around with the serial connection on this machine, and I discovered that the serial out line was not working. I traced the dead signal back from the DB25 serial connector to the 2N5226 transistor where the the pulsing signal returned. After some head sc...

Replying to myself again ;-) I found a program called DISKREAD.lod in the Win OSI emulator. I have loaded this via serial on my machine and it seems to work. Although I was testing it with a blank unformatted disk, it seemed to step through the tracks and dumps 00's out the serial port. So I guess t...

As with everything related to this drive, I don't know if I've fix the problem permanently. I did manage to get the motor back together. After a bit of head scratching I struck upon a solution for getting the springs and brushes into place. motor.jpg As you can maybe see from the photo there are two...

I'm still having issues with this drive. I powered it up today to do some test in. I was trying to create a 65D disk via a serial connection as documented here: http://osiweb.org/osiforum/viewtopic.php?f=5&t=66 Anyway, after a while the drive started slowing down and speeding up and slowing again, u...