W83977ATF Datasheet, PDF (33/207 Pages) Winbond – WINBOND I/O

HEAD (Bit 3):
This bit indicates the complement of HEAD output.
0 side 0
1 side 1
INDEX (Bit 2):
This bit indicates the value of INDEX output.
WP (Bit 1):
0disk is write-protected
1disk is not write-protected
DIR (Bit 0)
This bit indicates the direction of head movement.
0 outward direction
1 inward direction
In PS/2 Model 30 mode, the bit definitions for this register are as follows:
7 65 43 ²¹ 0
W83977ATF
PRELIMINARY
DIR
WP
INDEX
HEAD
TRAK0
STEP F/F
DRQ
INIT PENDING
INIT PENDING (Bit 7):
This bit indicates the value of the floppy disk interrupt output.
DRQ (Bit 6):
This bit indicates the value of DRQ output pin.
STEP F/F (Bit 5):
This bit indicates the complement of latched STEP output.
TRAK0 (Bit 4):
This bit indicates the complement of TRAK0 input.
Publication Release Date: April 1998
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Revision 0.52