Philips PCL304 - Rom; Serial & Parallel Port Assignments

The
system
board
can
consists
of
the
following
memory
types:
Conventional Memory:
This
is
the
memory
from
OKB
to
640KB
and
is
used
in
Real
Made
by,
e.g.,
DOS.
Extended Memory:
This
is
all
addressable
memory
above
the
1MB
border
and
can
only
be
accessed
by
the
CPU
when
it
is
working
in
pro-
tected
mode.
Expanded Memory:
Expanded
memory
is
not
addressable
by
the
CPU,
but
must
be
mapped
via
I/O
into
addressable
memory
within
the
first
1MB
of
address
space
in
memory
page
frames
of
16KB.
The
chips
in
this
system
support
LIM-EMS
4.0.
Shadow Memory:
This
is
memory
between
640KB
and
1MB
which
is
normally
not
accessible
unless
the
chips
in
the
system
are
program-
med
to
enable
this
memory
to
copy
ROM
into.
It
can
also
be
mapped
to
addressable
memory
for
use
as
normal
RAM.
NOTE:
An
expansion
board,
connected
via
an
expansion
box,
with
expanded
memory
can
NOT
co-exist
with
the
on-board
ex-
panded
memory.
Only
one
of
the
two,
together
with
its
dri-
ver,
may
be
installed.
2.2.4 ROM
The
system
board
contains
one,
128K
by
8-bit
EPROM
mo-
dule.
The
ROM
is
not
parity
checked
and
has
an
access
time
of
200ns.
The
ROM
is
a
combined
BIOS
containing
the
system
BIOS
and
video
BIOS.
It
also
contains
the
power
on
testing
and
boot
loader.
To
gain
faster
access,
the
BIOS
can
be
copied
to
RAM
du-
ring
power
on
(refer
to
section
4.1).
The
system
BIOS
is
present
at
the
following
location:
At
the
top
of
the
first
1
Mbyte
of
address
space
(0F0000
h
-
OFFFFF
h)
The
video
BIOS
is
present
at
the
following
location:
In the area from 512 Kbyte to 576 Kbyte
(0E0000 h - OEFFFF h)
2.2.5 VO Connections
On
the
main
board,
the
following
Input/Output
connections
are
provided:
CN2:
Expansion
slot
connector.
This
connector
is
located
at
the
rear
side
of
the
notebook.
CN11:
20-pin
flexible
flat
cable
diskette
drive
controi/data
connector.
CN6:
44-pin
header,
AT-bus
connector,
used
to
connect
AT-
embedded hard disk drives
DB-9P, serial port connector. Via the SETUP program
this port can be disabled, or can be configured as
PORT 1. PORT 1 has the base I/O address 3F8h.
For COM port assignments, refer to subsection
2.2.4.1.
CN:
2-3
Ji: DP-25P, serial port connector. Via the SETUP program
this port can be disabled, or can be config/ted as
PORT 2. PORT 2 has the base I/O address of 2F8h.
For COM port assignments, refer to subsection
2.2.4.1.
DB-25S, parallel port connector. Via the SETUP pro-
gram this port can be disabled, or can be ¢Onfigured
as PORT 2. PORT 2 has the base I/O address 378h.
For LPT port assignments, refer to subsection
2.2.4.1.
CN4:
CN1: DB-15S, analog video connector. This pot can be
disabled/ enabled via software, [Fn] + [F10}.
CN14: 6-pin, Mini-Din type keypad connector. This port sup-
ports AT compatible types only.
CN13: 6-pin, Mini-Din type PS/2 Mouse connector. This port
supports PS/2 compatible types only.
2.2.6 Serial And Parallel Port Assignments
The serial ports require eight consecutive I/O addresses for
access to the control and status registers. COM1is always
assigned to the highest /O address (when using only one
port, this may be either on 2F8h or 3F8h). If two serial ports
are installed COM2 is assigned to the next lower I/O ad-
dress (COM1 is assigned to 3F8h and COM2 is assigned to
2F8h). The table on the next page gives the three possible
configurations:
Configuration Base Port Base Port
Addr. Addr.
1 - - 2F8h COM1
2 3F8h COMi - -
3 3F8h COM1 2F8h COM2
Fig. 2-3
The parallel ports require three consecutive I/O addresses
for access to the control, status and data registers. LPT1 is
always assigned to the highest /O address available (when
using one parallel port, this may be on 278h, 378h or
3BCh). If two parallel ports are installed, LPT2 is assigned
to a lower V/O address. If three parallel ports are installed,
LPT3 is assigned to the lowest I/O address. The following ta-
ble gives the seven possible configurations:
Configu- Base Port Base Port Base Port
ration Addr. Addr. Addr.
1 - - - - 278h LPTi
2 - - 378h LPT1 - -
3 3BCh LPT1 - - - -
4 - - 378h LPT1 278h LPT2
5 3BCh LPT1 - - 278h LPT2
6 3BCh LPT1 378h LPT2 - -
7 3BCh LPT1 378h LPT2 278h LPT3
Fig. 2-4
CS 55 800