IBM 5150 Hardware Reference Manual

Adapter Inputs
-Index
-Write Protect
r"\
-Track 0
-Read
Data
The selected drive supplies one pulse per
disk revolution on this line.
The selected drive makes this line active
if
a write protected diskette is mounted in the
drive.
The selected drive makes this line active
if
the read/write head is over track O.
The selected drive supplies a pulse on this
line for each flux change encountered on the
disk.
2-107

IBM 5150 Specifications

General

Processor	Intel 8088
Clock Speed	4.77 MHz
RAM	16 KB - 256 KB
Manufacturer	IBM
Model	5150
Release Year	1981
Storage	5.25-inch floppy drives
Graphics	MDA or CGA
Operating System	IBM PC DOS
Ports	Cassette, keyboard
Expansion Slots	5