Date   : Thu, 05 Feb 1987 12:10:41-EST
From   : prindle@nadc.arpa
Subject: re: c64 to cpm

Unless you own the unlikely combination of a C64 and a C1571 (not 1541) disk
drive, you cannot write a CP/M diskette for Osborne, Epson, etc.  The reason
is that the 1541 disk drive *cannot* write MFM or FM format diskettes as used
by virtually every other system except APPLE.  These drives write only a form
of NRZ encoding called GCR (Group Code Recording) - totally unreadable by
any other drive without special hardware/controller.  This was the basic
reason why C64 CP/M never seriously caught on - there was no way, other than
via modem, to get programs in or out!  And even with a 1571 drive hooked to
a C64, I know of no utilities written explicitly for the 64 to do the necessary
copy.

On the other hand, there are several public domain utilities for the C128 with
C1571 disk drive, which will copy files from normal CBM format to any of a
variety of CP/M formats, Osborne MFM being one of the defaults.  I believe
the C128 CP/M program RDCBM20 (see [SIMTEL20]PD:<CPM.C128>RDCBM20.LBR) would
be the easiest to use, and it does the necessary translation for text files
from Commodore character set to ASCII.  The latest Commodore FORMAT.COM
utility will allow you to format an Osborne diskette too (not sure about the
Osborne Executive though - maybe just the Osborne 1).

So if this conversion you require is a one-time process, beg or borrow a 128
to do the job.  The 1571 will read the C64/1541 diskettes just fine.

Sincerely,
Frank Prindle
Prindle@NADC.arpa