fred@cbmvax.cbm.UUCP (Fred Bowen) (09/24/86)
I have recieved several requests for information regarding
the creation of MFM-formatted disks using the Commodore 1571
disk drive. Hopefully this is enough to get you started. A
new FORMAT.COM file for C128 CP/M 3.0 should be available
pretty soon- watch your favorite BBS for it.
Please refer to the 1571 Disk Drive User's Guide, Appendix G,
page 101, for a complete description of the FORMAT MFM burst
command. The table below contains the data required to create
a particular MFM disk format. MD and SS are given as binary
values; the rest are decimal:
FMT MD SS IL N LT NS
Epson QX10 01100110 10000001 0 2 39 10
Osborne DD 01000110 10000001 0 3 39 5
Kaypro II 01000110 10000000 0 2 39 10
Kaypro IV 01010110 10001010 0 2 39 10
IBM SS 01000110 10000001 0 2 39 8
IBM DS 01100110 10000001 0 2 39 8
MD is the Mode byte 2
SS is the Starting Sector number 3
IL is the Interleave 4
N is the Sector Size 5
LT is the Last Track number 6
NS is the Number of Sectors 7
The following BASIC program demonstrates how a FORMAT MFM
command can be sent to a 1571 drive:
10 OPEN 15,8,15
20 PRINT#15,"U0"+CHR$(102)+CHR$(129)+CHR$(0)+CHR$(2)+CHR$(39)+CHR$(10)
30 CLOSE 15
The example above formats the disk in unit #8 using the Epson
parameters. Of course, you must still install the necessary
boot and directory sectors to make your DOS (CP/M) happy. The
higher-level 1571 DOS commands, such as Load, Save, and Dir,
will never be happy with non-Commodore formats, needless to
say, right?
--
Fred Bowen uucp: {ihnp4|seismo|caip}!cbmvax!fred
arpa: cbmvax!fred@seismo.CSS.GOV
tele: 215 431-9100
Commodore Electronics, Ltd., 1200 Wilson Drive, West Chester, PA, 19380