IBM Personal System/2 60 User Manual

System
Board
POS
Register
2
(Hex
01
02)
When
the
system
board
is
in
the
setup
mode,
the
diskette
drive
controller,
serial
port,
and
parallel
port
are
controlled
by
this
read/write
register.
Reading
this
register
returns
the
current
state
of
these
system
board
functions.
Bit Function
7
Disable
Parallel
Port
Extended
Mode
6,
o-NOA
5 Parallel Port Select
Enable Parallel Port
Serial Port Select
Enable Serial Port
Enable Diskette Drive Interface
Enable System Board
Figure
2-4.
System
Board
POS
Register
2
(Hex
0102)
Bit7
Bits 6, 5
When
set
to
0,
this
bit
allows
the
parallel
port
to
be
configured
as
an
8-bit
parallel
bidirectional
interface.
When
set
to
1,
this
bit
disables
the
bidirectional
mode.
This
bit
is
set
to
0
at
power-on,
and
POST
sets
it
to
1.
These
bits
select
the
configuration
of
the
system
board
parallel
port.
Bits
65
Assignment
Hex
Address
Interrupt
Level
00
Parallel
1
03BC
-
03BF
7
o1
Parallel
2
0378
-
037B
7
10
Parallel
3
0278
-
027B
7
11
Reserved
==
-~------------
-
Figure
2-5.
Parallel
Port
Select
Bits
Bit 4
Bit 3
Bit 2
Bit 1
2-8
When
this
bit
and
bit
0
are
set
to
1,
the
system
board
paraliel
port
is
enabled.
When
set
to
1,
this
bit
sets
the
system
board
serial
port
as
Serial
1
(addresses
hex
03F8
through
O3FF),
which
uses
interrupt
level
4.
When
set
to
0,
this
bit
sets
the
serial
port
as
Serial
2
(addresses
hex
02F8
through
02FF),
which
uses
interrupt
level
3.
When
this
bit
and
bit
0
are
set
to
1,
the
system
board
serial
port
is
enabled.
When
this
bit
and
bit
0
are
set
to
1,
the
diskette
drive
interface
is
enabled.
Model
60
POS
—
Ociober
1990

IBM Personal System/2 60 Specifications

General

Brand	IBM
Model	Personal System/2 60
Category	Desktop
Language	English