Reading Disk Side 2?

[Tech]

Today I'm happy because the SuperCard Pro saved two rare 5.25" disks for commodore 64 from 1985. Greaseweazle failed to make good image of these disks, but the SCP just did it in the first try without any hassle as with the gw!

But there are two more disks to save! SCP could make images for two remaining disks. I was able to list their contents in a C64 emulator (LOAD"$",8 then LIST), but whenever I load them to run the emulator freezes! I'm not sure if the disks are beyond saving or if there is something I can do to save them?

The two disks also have programs on both sides. I was able to read first side, even though without much success as mentioned above. I flipped the disks and read the other side but the SCP complained about missing index. I disabled the index requirement from the menu, and set the copy mode to Splice, but still no recovery from the back sides whatsoever!

I'd appreciate if someone can help to save these disks.

The floppy disk drive I'm using is 5.25" Chinon FZ-506.

Thank you!

[admin]

Are these original copy protected disks? If not, then you can use the Flux->d64 converter which will recover bad data from a disk. If these are copy protected then you can use SPLICE mode with 3 revolutions to create an image file and I can look at it. The tracks just need to be rotated. It could be that the disk is just damaged too. I would know by looking at the image file. You can send the image to data @cbmstuff.com

[Tech]

Email with attachment sent. I notice the resulted .scp images for sides 2 are small (25kb each)! While images for side 1 in the same format go into hundred of kilobytes! Maybe because I disabled index when read side 2? I'm not sure!

[admin]

I looked at your images... your drive is not reading the back side. So, you need to locate the jumper that allows the drive to read without the index pulse.

[Tech]

Thank you. I'll see if I can find the drive's manual or user another drive.

[Tech]

Unfortunately, all my 5.25" floppy drives need the "flippy" mode to read side 2's.

Instead of modifying the drives hardware, I wonder what if I copy the C64 disk into a flippy disk (with INDEX holes in both sides), then read side 2 using a regular floppy drive?

Here is my plan:
1. read the C64 disk as IBM360 (at splice 3) and save it .scp image. This makes SCP to read both sides.
2. write the .scp image to a flippy disk (has INDEX holes in both sides) as IBM360.
3. read side 2 of the flippy disk as C64 disk in SCP

Will this work?

[admin]

That won't work. The upper and lower heads are offset by several tracks. You MUST flip the disk over to read the backside - or use a modified disk drive - there are no exceptions.

I have not actually seen any 96 TPI disk drive that can't automatically read the back side of a disk when flipped over, once you have disabled the index pulse requirement with a jumper setting.

[Tech]

That won't work.  The upper and lower heads are offset by several tracks.  You MUST flip the disk over to read the backside - or use a modified disk drive - there are no exceptions.

That's unfortunate!

I have not actually seen any 96 TPI disk drive that can't automatically read the back side of a disk when flipped over, once you have disabled the index pulse requirement with a jumper setting.

I have two working 96 tpi drives and both have no jumpers to disable index pulse requirement; they are Chinon FZ-506 and Teac FD-55GFR. Also, my old 48 tpi Tandon TM100-2A drive refuses to read without index pulses.

[admin]

Jumper E2 controls how the INDEX pulse is used for the Teac FD-55GFR.  Change that jumper for that drive.  I am not sure which jumper controls how the INDEX functions on the Chinon drive.

[Tech]

As you know, there are different versions of TEAC FD-55GFR. Mine is FD-55GFR-153-U5 and it has no E2 jumper. In fact, there are many tutorials online about modifying this drive to read flippy disks, such as here.