Tandy 1000 drive works but no index pulse, reads random noise
#1
I am trying to image disks from a Tandy 1000, via the machine itself. This machine was set up with both a 5.25" floppy and a 3.5" floppy. I haven't done/tried anything with the 3.5" drive, but the machine boots and works off of the 5.25" disks I have with it.

To image the disks, I opened the Tandy chassis and removed the floppy cable from the board and plugged it into the SCP, ensuring that the pink line and tab on the socket matched up with pin 1. I turn the computer on to use as a power supply and plug the SCP into an old Windows 7 netbook I have. When I open the SCP app, both of the drive lights come on in sequence. Track test shows 42 on the 5.25" and 85 [iirc] on the 3.5" drives, everything seems very promising!

But the imaging fails saying "No index pulse detected". I changed the settings to:

DriveType: 5.25" - 48 TPI   (Is this setting important? What exactly does it change?)
Weakbits: Raw
Density: R>Low, W>Low
Index Sensor: R>Ignore, W>Ignore
Backside Control: None

Disk Types: IBM 360K
Copy Mode: Splice   ("Index" also works, even though Index is ignore?! What happens in that case?)
Start: T0 H0
End: T42 H1
Preservation on


When I image from Drive 0 to a file, it proceeds although every box is orange as it fills in. (Is that color meaningful?)

But now the final step, I can't seem to do anything with these images in HxC [or is there a better program for converting DOS-compatible disks?]. In fact in its "visual floppy disk" viewer it seems to be pretty much just random noise, I don't see anything that looks like data or sectors or anything promising.

I tossed one of my many tries up at http://extinguishedscholar.com/temp/tand...e2.scp.zip (update: and now a 96tpi at http://extinguishedscholar.com/temp/tand...ks.scp.zip) if you'd care to take a look. Tons of newbie questions already, but my main ones boil down to:

1. Is it expected that an old 5.25" drive in a Tandy 1000 wouldn't have an index sensor, or is that the first thing to troubleshoot?
2. What would cause the drive to "work" but yield only random data? Could the Tandy cabling be different than the SCP expects? [Seems pretty normal cable looking at it.]
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Tandy 1000 drive works but no index pulse, reads random noise - by natevw - 01-11-2020, 05:25 PM



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