ACT apricot - Page 123

Busy
DRQ
Lost
Data
CRC
Error
RNF
Protected
Not
Ready
FLOPPY DISK INTERFACE
A logic high on Busy indicates that the
command is in progress; logic low indicates
that the command sequence is complete.
A copy of the DRQ output to the lOP. A logic
high indicates that the FDC has data available
during the Read Track/Read Address
operations, and requires data during a Write
Track operation.
Logic high indicates that the lOP did not
respond to the DRQ output in time, and as a
result; valid data was not written onto the disk
during a Write Track operation/valid data was
not read from the disk during a read operation.
During the Read Address operation, a logic
high indicates a CRC error was detected within
the sector ID field. During the Read Track and
Write Track operations set to logic low.
Record
Not Found. A logic high indicates that
the Read Address operation was unable to
locate an ID field. During Read Track and Write
Track set to logic low.
Inverted copy of the WPRT input from the
drive, during the Write Track operation. Logic
high indicates that the selected disk drive
contains a write protected disk. During read
operations set to logic low.
Inverted copy of the READY input from the
drive. Logic high indicates that the drive is not
ready for a data transfer operation.