Full Version: IBM PS/2 Formatted Diskettes - Non-Standard
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
I have 3.5 diskettes that are IBM PC formatted and I am trying to read them with the Supercard Pro. They are low-density diskettes formatted as high-density. Unfortunately, they are standard formatted but non-standard bit rates and possibly rotation.

The IBM PS/2 series allowed a 720 K floppy disk, without holes punched, to be formatted at 1.44 MB. The diskettes work flawlessly in the PS/2 series (50z, 55sx, etc.) and they weren't readable on IBM clones. When the PS/2 was readily available, I never thought to copy these diskettes to the standard, dual punched high-density diskettes.

I ran across several old diskettes formatted this way. The good news is that I have a physical IBM PS/2 Model 50z (Micro Channel) on my shelf. The bad news is the diskette drive motor no longer spins. 

The attached image shows the results of the Supercard Pro reading the diskettes. My other IBM diskettes, both 5.25 and 3.5, work flawlessly. The splice method has recovered bad sectors in nearly every instance. These diskettes are simply a problem at this time.

Is there a way to get the Supercard Pro to read these diskettes short of buying a PS/2?
The SuperCard Pro is just a flux level reader/writer. It doesn't actually "read" anything, it just collects the flux that is read by the disk drive. If the drive can't read the flux (due to the disk being thought by the disk drive that it is low density when in fact it is high density) there might not be anything that you can do to force the drive to read the disk differently than it normally does.

No, having said that, there is one possibility though - you can try changing the DENSITY in the pull-down menu. That will invert the density line. This option was made because some disk drives have a jumper that sets this and sometimes it is backwards. If that disk drive pays attention to that signal (some ignore it), then that might force the drive into reading the opposite density that it normally does. It's worth a try.