Re: Apple 5.25 Diskettes?

[supertimer@aol.com (Supertimer)]

Patrick Schaefer <pa.schaefer@fz-juelich.de> wrote:

>Paul Guertin wrote:
>
>> Would it be possible to replace the drive head in a Disk ][
>> with a high-density head (that presumably has a stronger, more
>> concentrated magnetic field) and expect it to work without too
>> many modifications?
>
>You would have to replace the head amplifier, too. The easiest way
>should be using a complete TEAC55GFR HD drive with an Erphi or Ehring
>controller (PC drives need Step and Direction pulses instead of the four
>phases, therefore a Disk II controller cannot be used).
>
>There may still be a problem: HD drives expect a 500 kHz data stream
>instead of 300 (250) kHz.

At this point, it might be cheaper to get a BlueDisk card
from ///SHH Systeme.  This is an MFM controller card
for the Apple IIe and IIGS (specify when ordering since
the IIGS one uses a ROM with 16-bit code for faster
operation) that allows these computers to use standard
IBM PC compatible drives.  360k and 1.2M 5.25 disk
drives.  720k, 1.44M, and 2.88M 3.5 drives!

Naturally, with one of these cards and a PC drive, the
Apple IIGS can read and write MS-DOS disks.  ;-)

The controller also makes the PC drives do neat things.
720k on a 5.25 disk?  BlueDisk can do it.  800k on
a PC 3.5 disk drive too, but only in MFM, not GCR.

///SHH System is a Germany based company.