Tandy 2000 FDC chip question

[Eudimorphodon]

Pretty sure it’s standard Shugart no-twist jumper-it style, but I only say that because the Tandy 1000 is that way (unlike a normal PC clone) and it’d be a little weird if Radio Shack did anything else.

[falter]

Pretty sure it’s standard Shugart no-twist jumper-it style, but I only say that because the Tandy 1000 is that way (unlike a normal PC clone) and it’d be a little weird if Radio Shack did anything else.

Yeah its an untwisted cable with the drives jumpered for 0 and 1.

And no, the drive will not format as Drive B on the T1000. Just says track 0 bad.

[Chuck(G)]

Does the drive seek to track 0 on the T1000?

[Eudimorphodon]

And no, the drive will not format as Drive B on the T1000. Just says track 0 bad.

And just to sanity check, you're using double density disks, not high density? That's odd, I can't think of a good reason why the drive wouldn't work unless it's actually broken.

[falter]

Yes I have piles of good quality DSDD disks.

On my first try with formatting I saw the head move back. Curious, after the error I moved it forward again gently and then reinsert the disc and reran the format command. But this time it did not go backwards.

[Chuck(G)]

Check the pins on the 7416 that I cited above. It's not usual for those to go bad under load. In a pinch, you can get away with a 7406--actually a better chip for this application.

[SomeGuy]

Just glancing at this thread...

To reduce the variables at play, I would focus on writing a Tandy 2000 boot disk image with ImageDisk. Don't bother with other DOS tools, as they can have problems since IBM PCs never supported "quad density" drives.

First, verify the floppy cable is fully functional. Cables should not just go bad, but they do. Use an ohm meter to verify each pin. I seem to recall also running in to the "head moves one direction" before, and as I recall it was the $##@%#$@ cable.

To write a Tandy 2000 boot disk image with a 1.2mb drive, load the image in ImageDisk, make sure double stepping is set to OFF. Use DSDD media to write the image. A standard 1.2mb drive uses 300KBPS data rate for low density medial. If ImageDisks tries to write the image at 250KBPS instead of 300KBPS, use its "Translate" options to make it write at 300KBPS. Since both quad density and 1.2mb drives are 96TPI, you don't have to worry about readability issues such as those with 360k drives.

If you do manage to connect one of the quad density drives to a PC, again, use ImageDisk to write the image, and set double stepping to OFF. Quad density drives use 250KBSP data transfer rate because they spin slower. If the image attempts to write at 300KBPS (which is often the default), use ImageDisk's Translate options to make sure it writes at 250KBPS.

[Chuck(G)]

Did you miss the post where the drive doesn't seek to home at any point in the power/boot sequence?

[grumpyx]

When working a T2K I normally use my HxC to boot with while testing the system out. Then I move on to fixing the drive, normally just the grease has hardened up and not letting the head drop all the way down.

I used IMD for most of my T2K images on Tandy2000.com for some I ended up using my SCP to get a good image. All of the DOS Images are IMD and work in the HxC emulator on the T2K.

[Chuck(G)]

I see no reason that the Gotek with FlashFloppy would not work with the 2K either.

But if you're after the authentic Tandy 2K, you're pretty much confined to real floppy drives and media. But for authenticity, why would one even bother with the "not quite PC compatible" Tandy 2000?