PS/2 Model 30 Mode
7
6
5
4
3
2
1
0
INT
PENDING
DRQ
STEP TRK0 nHDSEL INDX
F/F
WP
nDIR
RESET
COND.
0
0
0
N/A
1
N/A
N/A
1
BIT 0 nDIRECTION
Active low status indicating the direction of head
movement. logic "0" indicating inward
BIT 4 TRACK 0
Active high status of the TRK0 disk interface
input.
A
direction a logic "1" outward.
BIT 5 STEP
Active high status of the latched STEP disk
interface output pin. This bit is latched with the
STEP output going active, and is cleared with a
read from the DIR register, or with a hardware
or software reset.
BIT 1 WRITE PROTECT
Active high status of the WRITE PROTECT disk
interface input. A logic "1" indicating that the
disk is write protected.
BIT 2 INDEX
Active high status of the INDEX disk interface
BIT 6 DMA REQUEST
input.
Active high status of the DRQ output pin.
BIT 3 nHEAD SELECT
BIT 7 INTERRUPT PENDING
Active high bit indicating the state of the Floppy
Disk Interrupt output.
Active low status of the HDSEL disk interface
input. A logic "0" selects side 1 and a logic "1"
selects side 0.
20