Tandy 1000 SX - MFM/RLL HDD Trouble

[phil.bischof]

I have a Tandy 1000 SX, and I am having a very, very hard time getting any of the old hard drives that I have working. I have a Seagate ST-238, and a Miniscribe 3438 P. Both are RLL hard drives. I am using a Western Digital WD1002A-27X as the controller card. I don't believe this has anything to do with Tandy specifically, but just posting it here since it's related and the knowledge base here is fantastic.

The ST-238 spins up, performs the low level format using the built-in (debug -G=C800:5) that the controller provides, and also completes a Standard Init in SpeedStor. However, after everything finishes, SpeedStor says it can't access the drive partition table and the drive is unusable. FDISK does the same thing, but with a more generic error message.

At first, the Miniscribe stepper motor was completely stuck, but after manually working it back and forth and lubricating it, it started working well. Then the diag light was flashing the code for Zero Track Interrupt Misadjusted, so I stepped through that process and got it back in line. It now LLF properly, and also does the Standard Init in SpeedStor, but it reports like 55 bad cylinders. After marking the bad sectors though, the partition fails with the same issue - "Unable to access drive partition table - drive unusable".

I desperately want to get one of these working. Can anyone give me any advice? I am not opposed to opening them up and checking internals, and I have a scope so I can check things on that level as well. I'm just lost and don't know what to try next.

If there is any other info that would be helpful, let me know and I will post.

Thanks guys!!!

 

[phil.bischof]

Nobody has any ideas?

 

[NeXT]

Are you performing the format with the drive cold? Track alignment does change between a cold and a warmed-up drive enough it can cause issues.
Also try completely ignoring Speedstor and trying a warm-up of about half an hour, then an LLF, then an FDISK and then lastly a DOS Format.

 

[phil.bischof]

I have tried LLF cold, and then left it sit at the SpeedStor screen after it completes (because I fell asleep ) and then resumed the next morning, but never tried just letting it sit there and warm up first. I will give that a try thank you!! Anything specific I should do to "warm it up"? Or just boot the Tandy off the floppy disk into DOS and let it sit there for a bit?

 

[NeXT]

Just turn the machine on and let the drive idle.
I have an Apricot here where I tried an LLF while cold and as it warmed up it would eventually fail to read, so I followed Apricot's own advice to let the system warm up for half an hour and then do it and beyond having to wait 10-15 minutes on a cold start before it would be able to reliably read data it has not been an issue since.

 

[phil.bischof]

Tried this and same result. LLF complete successfully but fdisk fails stating it can't read the drive partition and speedstor fails partitioning it with the same error.

I guess it's possible but I just find it hard to believe that both drives are failing with the exact same symptoms. It makes me wonder if it's something with my cables. I have two different controller cards and I get the same problem regardless of which one I use.