Why would you want to set 96TPI drive to 48TPI
#1
I have not been able to find this addressed on the forum but it may well be. They may also be silly questions Smile

Q1) Why would one want to set the jumper on a 96TPI 5 1/4" drive to 48TPI. Does this control the step size on the drive only? In other words, if the jumper is set at 48TPI and you ask the drive to step to the next track it will step twice as far as if it were jumpered to 96TPI?

Q2) Density setting. My drive, Panasonic JU475-4 does not have a separate density setting. If the drive has no such setting is this then a function that can be 'soft configured' by the PC or SPC? What does this density setting do? Does it actually change the read/write heads drive characteristics? Or is it just a way to fix a drive to only work with a certain type of media?

Q3) For the JU475-4 you remove the GX jumper so that it does not try to use the index sensor. This lets you image the backside of a C64 disk without a second index hole. Does this imply that if you have a commercial disk and need to image it in INDEX mode (rather than SPLICE) that you would need to install the jumper (or use a switch)?

Thanks!
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#2
1) You wouldn't. Yes, it will step twice as far. If you have a 96 tpi drive, leave the stock settings. SCP software will double-step when necessary, based on the drive type (48tpi/96tpi) and the disk type you select.

2) Yes, it does... maybe not jumpered, but that can (and is) controlled from a line on the floppy port.

3) No. The GX jumper doesn't ignore the index hole. It simply allows the motor to spin and backside be read. The index sensor still works like normal, but you don't get a pulse when reading the back side. So, you have to disable the INDEX PULSE in the pull-down menu when reading/writing the backside of a disk. When reading the frontside, just re-enable the pulse.
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#3
(01-14-2020, 12:34 AM)admin Wrote: 1) You wouldn't.  Yes, it will step twice as far.  If you have a 96 tpi drive, leave the stock settings.  SCP software will double-step when necessary, based on the drive type (48tpi/96tpi) and the disk type you select.

2) Yes, it does... maybe not jumpered, but that can (and is) controlled from a line on the floppy port.

3) No.  The GX jumper doesn't ignore the index hole.  It simply allows the motor to spin and backside be read.  The index sensor still works like normal, but you don't get a pulse when reading the back side.  So, you have to disable the INDEX PULSE in the pull-down menu when reading/writing the backside of a disk.  When reading the frontside, just re-enable the pulse.

Thanks!

So the GX jumper just tells the drive it is OK to spin even though it does not see the index pulse? Whereas the SCP expects or ignores the pulse based on the SCP software settings. (Sorry to be pedantic, just curious at how things work.)
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#4
Yes, that is all correct.
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