W83877ATF Datasheet, PDF (33/191 Pages) Winbond – enhanced version from Winbonds most popular I/O chip W83877F

INDEX (Bit 2):
This bit indicates the value of INDEX output.
WP (Bit 1):
0
disk is write-protected
1
disk 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 6 5 4 3 ²¹ 0
W83877ATF
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.
HEAD (Bit 3):
This bit indicates the value of HEAD output.
0 side 1
1 side 0
INDEX (Bit 2):
This bit indicates the complement of INDEX output.
- 29 -
Publication Release Date: April 1998
Version 0.51