IBM 5150 PC Technical Reference (6025005, August, 1981) (PDF)

Table 17. Status Register 3
BIT
NO. NAME SYMBOL DESCRIPTION
07 Fault FT This bit is used to indicate the status of
the Fault signal from the FOO.
OS Write Protected WP
05 Ready RY
04 Track 0 TO
03 Two Side TS
02 Head Address HO
01 Unit Select 1 US 1
DO Unit Select 0 US 0
This bit is used to indicate the status of
the Write Protected signal from the FOD.
This bit is used to indicate the status of
the Ready signal from the FDD.
I
This bit is used to indicate the status of f:
the Track 0 signal from the FOO. ~
This bit is used to indicate the status of
the Two Side signal from the FDD.
This bit is used to indicate the status of
Side Select signal to the FOD.
This bit is used to indicate the status of
the Unit Select 1 signal to the FOO.
This bit is used to indicate the status of
the Unit Select 0 signal to the FOD.
~
I
Programming Summary
DPe Registers (Ports)
FDC Data Reg
FDe Main, Status Reg
Digital Output Reg
I/O Address 3F5
110 Address 3F4
I/O Address 3F2
Bit 0 Drive OO:DR#A 10: DR #C
1 Select 01: DR #B 11: DR #D
2 Not FDC Reset
3 Enable INT & DMA Requests
4 Drive A Motor Enable
5 Drive B Motor Enable
6 Drive . C Motor Enable
7 Dnve D Motor Enable
All bits cleared with channel reset.
2-103