their default values. A status byte is returned immediately
after issuing a LOCK command. This byte reflects the
value of the LOCK bit set by the command byte.
COMPATIBILITY
The FDC37C669 was designed with software
compatibility in mind. It is a fully backwards-compatible
solution with the older generation 765A/B disk controllers.
The FDC also implements on-board registers for
compatibility with the PS/2, as well as PC/AT and PC/XT,
floppy disk controller subsystems. After a hardware reset
of the FDC, all registers, functions and enhancements
default to a PC/AT, PS/2 or PS/2 Model 30 compatible
operating mode, depending on how the IDENT and MFM
bits are configured by the system bios.
ENHANCED DUMPREG
The DUMPREG command is designed to support system
run-time
diagnostics
and
application
software
development and debug. To accommodate the LOCK
command and the enhanced PERPENDICULAR MODE
command the eighth byte of the DUMPREG command
has been modified to contain the additional data from
these two commands.
69
SMSC [ SMSC CORPORATION ]
