Tandy 1400LT upgrade - update

So all the parts finally arrived and I attempted to replace the sticky B: drive with a Gotek.

Short update: Failure.  I will have to create my own 26-34 pin adaptor.

Long update:

The goal was to replace the B: drive with a Gotek.  If I got that to work, I'd replace the A: drive as well.  I got a 26-to-34 pin adaptor from eBay.

I have both a standard Gotek + FlashFloppy and an OpenFlops and I tried them both.

So, partial disassembly and unplugged the B: drive.  I plugged the 26-to-34 pin adaptor into the Gotek and hooked the B: drive into the cable.

First issue: The Gotek must be set to the S0.  Otherwise, the A: drive won't read at all.  Simple fix of moving the jumper and tried again.

This time A: booted up fine, but B: would not do anything.  I tried the OpenFlops with the same results.

Next attempt, I hooked up just the Gotek.  No other floppies.  That worked.  So I know that everything works.  Why doesn't it work with another floppy?

The answer is in the Tandy 1400LT Service Manual.  Go to the Appendix C - 3.5 inch FDD Specification, Physical Interface.

The problem is Pin 6.  For the Tandy 1400LT, that pin is Drive Select 1.  But in the 26 pin floppy specification, that pin is Disk Change.  So a general 26-to-34 pin adaptor won't work.  I would have to build my own specific for the 1400LT.  That's a project for another time.

But the day wasn't a complete loss.  I had purchased yet another 1400LT on eBay that was non-working and was able to recover many parts - including the floppy drives.  So while I had the computer apart, I replaced the sticky B: drive with one from the parts system.  So the sticky B: drive is fixed.

I'll see if it's worth my time to build my own 26--to-34 adaptor.