16 Jun
2006
16 Jun
'06
10:29 p.m.
Hi
I've been writng some code to transfer disk images to my Olivetti
M20. It uses 340K but with the first track being FM while the
rest is MFM. I've found a good controller to handle the FM but
I'm still having a stepper problems.
When I transfer, using the hard drive as the source, things work
fine. When I try to transfer from the 1.44M drive, I have to do a
lot of Recal's on the 360K drive I'm using. I use DOS to fetch the
image from the 1.44M. When I do this, the stepper on the 360k
drive can't keep up and it corrupts the position. This requires a
A silly question. Are you telling the floppy controller chip which drive
you're using when you wrote your own code. I don't mean selecting the
drive with the I/O port that controls the drive select and the motor-on
lines, I mean when you send a command to the FDC, you also include the
drive number there.
The reason is that the FDC (should?) keep a separate track position for
each drive, and will use the approprtiate one when you issue a seek, etc.
If you're telling the FDC that your 360K drive is drive 0 when it isn't,
accesses to the 1.44M drive (the real drive 0, I assume) will change
where the controller thinks the head is on the 360K drive.
-tony