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Full Version: Proper way to dump 5.25" 48TPI disks using 96TPI drives?
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I'm using a Toshiba ND-0801GR, which is a 1.2MB 96TPI drive. However, I've got some disks I want to dump which are 48TPI. I've figured out the jumpering on the drive to make it so that it properly switches between 300RPM and 360RPM according to the "Density" option in SCP software.

The problem I'm having, though, is that I can't figure out the proper settings for SCP to get usable results on these disks. If I just dump using the "IBM 360K" setting, I end up with every other track is invalid or blank (according to Samdisk scan), which leads me to believe that probably the dump is dumping only half the tracks as well as the gaps between them.

Is there some way to force double stepping?

The other thing I'm confused about is the proper way to dump 1.2MB disks. I know it's been discussed some elsewhere, but I'm still confused. So 1.2MB disks are 80 tracks, but the 360K option in SCP only indicates it copies tracks 0-39, which is only 40 tracks. Am I supposed to use the 720K option so that I get an 80 track dump?
I need to look into this again. For now, use the C64 setting for imaging 48TPI disks with a 96TPI drive. Unless you check the "half tracks" box, it will always double step while reading/writing.
(11-18-2015, 11:51 PM)admin Wrote: [ -> ]I need to look into this again.  For now, use the C64 setting for imaging 48TPI disks with a 96TPI drive.  Unless you check the "half tracks" box, it will always double step while reading/writing.

Doesn't that only copy a single side, though? These are double sided PC disks, but from the Samdisk output it looks like in C64 mode only one side gets read.

For now, I'm just using the 720K / 1.44MB settings to read every track, then I can check the dump by having Samdisk skip every other track (-d option). I think I can actually have it re-write the image using just the even tracks too, but I haven't tried it.
Most people just copy ALL of the tracks (including the 1/2 tracks) using the 1.2MB option. I know Simon was doing this with writing the version that supports SCP image files, which is why the -d option is there. Simon did make a version that drives the SCP hardware directly. I know he planned on releasing it at some point. I will have to ask him about the progress on that version. If he released that then you could just use SAMDisk to read/write your images instead of the SCP software.

I will look into this, so we can conserve storage space.