Were the drives sold as working?

Floppy drives are generally configured as B: at the factory. If the BIOS is standard, the drive after the twist in the cable will be seen as A: by the system.

If they're spinning on command, that means they're connected correctly and detected correctly by the BIOS. (The BIOS would presumably throw an error at POST if there was a bad connection somewhere.)

Are you sure the platters are rotating or are you just going by the drive light? Run the drives outside of the case and verify they're spinning. (Set them up sideways so you can directly see the mechanism.)

Do the drives make any strange noises when they spin? If they're squealing either they need lubrication or the disks are bad. Manually inspect the disks and check that they can rotate smoothly in their cases.

The drives are physically spinning. I just tried to "FORMAT B:" on both and with a "new" 5.25-inch DSDD disk, DOS reports (for both):

Checking Existing Disk Format. [spins] Not Ready.

It is connected on the first set of connectors distant from the motherboard. Further out on the cable after the twist is the A: drive.

bp

Please clarify:

1) What model(s) are the 5.25" drives? It seems you don't even know whether they are DD or HD.

2) What kind of disks did you try reading? I don't think you can just stick in some disks from a TRS-80 Model 4 and read them on a standard PC. Did you try formatting a disk?

derSammler wrote:

Please clarify:

1) What model(s) are the 5.25" drives? It seems you don't even know whether they are DD or HD.

2) What kind of disks did you try reading? I don't think you can just stick in some disks from a TRS-80 Model 4 and read them on a standard PC. Did you try formatting a disk?

They are both TEAC FD-55BR, said both sellers. I don’t see that indication (or a conflicting indication) on the drives themselves, hence I tested in 1.2MB mode just in case. They are sold as 360K drives (which the stated model is), one was untested, one was stated as working.

Of course I am trying MSDOS disks on the system...

bp

All TEAC drives have a badge at the rear stating the model and serial number.

If it doesn't look like this:
https://www.dreamhardware.com/media/catalog/p … -u_3_large_.jpg

it's most likely not a TEAC drive at all.

I think the command you need for DOS 6.22 is FORMAT B: /F:360

However the Not Ready error suggests a hardware problem.

I had the same problem with two old Tandon drives that were in VERY bad condition. The lights would flash and the platters would spin but I just got 'Not Ready' whenever I tried to read a disk.

Eventually one drive blew up in a puff of smoke and they both went in the trash.

Are you sure your disks are ok ?

Also you should try to see if the head mechanism moves freely or not, greasing/oiling it shouldn't hurt. But be careful not to missalign the heads and move the head positionment detector

Also try (1) changing drive position on the cable, (2) removing the 3.5" drive, (3) a different cable, (4) this drive on a different computer, or (5) a different drive on this computer