Commodore COLT 286 User manual

SERVICE MANUAL
COLT 286
OCTOBER, 1989 PN-314118-02
C=z Commodore

SERVICE MANUAL
COLT 286
OCTOBER, 1989 PN-314118-02
INTERNATIONAL EDITION
COMMODORE “INTERNATIONAL EDITION” SERVICE MANUALS CON-
TAIN PART NUMBER INFORMATION WHICH MAY VARY ACCORDING TO
COUNTRY. SOME PARTS MAY NOT BE AVAILABLE IN ALL COUNTRIES.
Commodore Business Machines, Inc.
1200 Wilson Drive, West Chester, Pennsylvania 19380 U.S.A.
Commodore makes no expressed or implied war-
ranties with regard to the information contained
herein. The information is made available solely on
an as is basis, and the entire risk as to quality and
accuracy is with the user. Commodore shall not be
liable for any consequential or incidental damages
in connection with the use of the information con-
tained herein. The listing of any available replace-
-ment part herein does not constitute in any case
a recommendation, warranty or guaranty as to
quality or suitability of such replacement part.
Reproduction or use without'expressed permission,
of editorial or pictorial content, in any matter is
prohibited.
This manual contains copyrighted and proprietary information. No part
of this publication may be reproduced, stored in a retrieval system, or
transmitted in any form or by any means, electronic, mechanical,
photocopying, recording or otherwise, without the prior written permis-
sion of Commodore Electronics Limited.
Copyright
©
1989
by
Commodore
Electronics
Limited.
All
rights
reserved.

COLT 286 SERVICE MANUAL
TABLE OF CONTENTS
SECTION 1 — SPECIFICATIONS
SECTION 2 — OPERATION NOTES
SECTION 3 — TROUBLESHOOTING GUIDE
SECTION 4 — PARTS
SECTION 5 — SCHEMATICS

COLT 286 SERVICE MANUAL
TECHNICAL SPECIFICATIONS
COLT 286 AT Compatible
MEMORY .
ROM Autoconfig BIOS
RAM on board 640 kbytes Base RAM
RAM expandable
‘on board n/a
on slots Yes; to 15 Mbytes
CPU
Type 80286-12
Clock speed 6, 8, 12 MHz
80287 Math Co-processor Socket on board
Number of Slots Two AT, one XT slots
Operating System MS-DOS 3.3 included
KEYBOARD
Number of keys ASCII 101 — International 102
Type Enhanced AT
Numeric keypad Yes
Cursor keys 4 - inverted T layout
Function keys 12
POWER SUPPLY
Type High-efficiency switching power supply with integrated cooling fan
Maximum configuration 2 floppy disk drives, one hard disk drive, 3 expansion cards; or 1 floppy
supported disk drive, one hard disk drive, 1 tape unit, 3 expansion cards
INPUT/OUTPUT PORTS
RS232C serial Built in
Centronics parallel Built in
Mouse port Built in for 1352 Mouse — Microsoft bus mouse configuration
STORAGE
Floppy drive Build in controller supports one or two drives
Hard drive One AT hard disk built in
Maximum internal Two half-height 3.5 or 5.25 inch floppy disk drives and one half-height
configuration 3.5 inch hard disk drive
VIDEO
EGA EGA Wonder800 + video card
CGA EGA Wonder800 + video card
MDA EGA Wonder800 + video card
Hercules EGA Wonder800 + video card
(See EGA Wonder800 + User’s Guide for video details.)
COMPATIBLE MONITORS
EGA, RGB Color, TTL Monochrome, Multisync Monitors
OTHER FEATURES
Built-in real-time clock/calendar with battery backup
External Configuration switches
Hardware Reset switch
Audio connector — (1V peak-to-peak; 1 K ohm impedance) provides external audio for enhanced sound; to be connected
to a monitor’s pre-amp circuit.
COMMODORE ADD-ON OPTIONS
Second floppy disk drive
1352 mouse
MPS 1250 printer
1402 TTL monitor (mono)
xxxx monitor (mono) with sound
1084 RGB monitor (color) with sound

EGA
WONDER800®
SPECIFICATIONS
VIDEO
DISPLAY
BUFFER
256K
bytes
SYNC
SIGNALS
.
Separate
horizontal
and
vertical
sync
in
TTL
levels
Horizontal
35kHz
-
MultiSync
monitors
(800x600)
31.5kHz
-
MultiSync
monitors
(640x480)
21.8kHz
-
EGA
monitors
15.75kHz
-
RGB
monitors
18.432kHz
-
TTL
Monochrome
monitors
Vertical
56
Hz
-
MultiSync
monitors
(800x600)
60
Hz
-
MultiSync
monitors
(640x480)
60
Hz
-
EGA
monitors
60
Hz
-
RGB
monitors
s0
Hz
-
TTL
Monochrome
monitors
CONNECTOR
9-pin
D
shell
(Female)
IBM
standard
MONITOR
COMPATIBILITY
TTL
Monochrome
Display
RGB Color Display
EGA
Enhanced
Color
Display
MultiSync monitor
SIZE
5.25" x4.2"
POWER
+5V
+
5%,
@
0.6
AMP
typical
ENVIRONMENT
COLT
286
SERVICE
MANUAL
Ambient
Temperature
50°
to
122°
F
(10°
to
50°
C)
operation.
32°
to
162°
F
(0°
to
70°
C)
storage
Relative
Humidity
5%
to
90%
non-condensing
operation.
0%
to
95%
storage
BUS
AT standard
BUS LOADING
No more than 2 LS TTL load
CONNECTOR SPECIFICATIONS
DB9 Connector
Pin No. Signal
Ground
Secondary Red/Ground
Primary Red
Primary Green
Primary Blue
Secondary Green/Intensity
Secondary Blue/Mono Video
Horizontal Retrace
Vertical Retrace
vsosauwu
2
WN
-

COLT 286 SERVICE MANUAL
SECTION 2
NOTES — OPERATIONS GUIDE

COLT 286 SERVICE MANUAL
OPERATION NOTES
THE
COLT
286
HARDWARE
CONF
IGURATION
USING
THE
COLT
286
SETUP
UTILITY
n
a
he
builtein
$
ulity
to
give
i
has
finished
booting
and
the
C>
prompt
has
appeared,
you
can
use
the
built-in
Setup
utility
to
giv
a
nem
detailed
information
on
your
COLT
286
configuration.
To
run
the
Setup
utility,
hold
down
the
Control
and
Alt
keys
and
simultaneously
press
the
Esc
key.
The
main
menu
of
the
Setup
utility
will
appear
and
will
look
like
this:
f Commodore Setup Utllity N
Date
23.08.88
Hard
Disk
Type
Inforgation
:26:26
Time
u
1.444
Type
Cyln Head Sect
W-pc
L-zone
Size
Diskette)
KCNE
1
306
4
17
128
305
10MB
HardDiskl
en
2
615
4
17
30
6ls
20MB
hardDisk2
UNE
3
65
6
17
%0
615
S0MB
Video
SPECIAL
4
90
8
17
5l2
%0
62MB
Coprocessor
NONE
5
4
6
17
512
90
46MB
Baze Heno
60x
6
615
4
17
NONE
615
203B
4 OK 7 42 8 17 256 SL SON
Extended
Nenory
e
73
5
17
NONE
733
30MB
Base
nenory
found:
640
KB
9
00
15
17
NONE
SOl
112MB
Extended
nenory
found:
000
KB
10
820
3
17
NONE
820
20MB
Use
}.
|toselect
itens
1
855
5
17
NONE
855
35MB
Use
>,
to
select
predefined
12
855
7
17
NONE
855
49MB
values 13 306 8 17 128 319 20MB
Use
<PgDn>
to
vier more
hard
disk
M
73
7
17
NONE
733
42MB
types
s
0000
008
Press
<Esc>
to
abort
SETUP
6
602
417
0
63
20
Press <End> to exit and update
\_ Press Fl for secondary SETUP window /
FIGURE 1. COMMODORE SETUP UTILITY MAIN MENU
As .noted on the Setup screen, you can use the cursor keys and the keyboard to define or change the system configura-
tion, as follows:
° Use the up and down cursor keys to move from option to option in the main menu.
° Use the left and right cursor keys to select the predefined entries for each option. .
° Use the keyboard to type in any information that is not predefined.
°
Use
PgDn
to
display
additional
hard
disk
types
(see
Figure
2).
°
Use
the
F1
key
to
display
the
secondary
setup
window.
° Use the Esc (Escape) key to abort Setup.
o
Use
the
End
key
to
exit
Setup
and
update
the
settings.
Following
is
specific
information
about
the
various
Setup
menu
options.
Setting
the
Date
and
Time
for
the
Real
Time
Clock/Calendar
The
COLT
286
has
a
Real
Time
Clock/Calendar
with
a
battery
backup.
This
means
that
once
set,
the
clock/calendar
will
‚keep
the
correct
date
and
time
even
when
the
computer
is
turned
off.
You
use
the
first
two
lines
of
the
Setup
Utility
to
set
the
Real
Time
Clock/Calendar,
as
follows:
Date:
Allows
you
to
set
the
correct
date
into
the
Real
Time
Clock.
This
option
does
not
have
any
predefined
entries;
simply
enter
the
date
from
the
keyboard,
in
the
format
dd/mm/yy.
Time:
Allows
you
to
set
the
correct
time
into
the
Real
Time
Clock,
without
invoking
MS-DOS.
This
option
also
does
not
have
any
predefined
entries;
simply
enter
the
time
from
the
keyboard,
in
the
format
hh:mm:ss.,
where
hh
=00-23,
mm
=00-59
and
ss=00-59.
Setting
the
Floppy
Disk
Drive
Options
vo
can
havea
maximum
of
two
floppy
diskettes
configured
into
your
COLT
286.
The
next
two
Setup
menu
options,
Diskette
1
and
Diskette
2,
allow
you
to
tell
the
system
how
many
floppy
drives
are
available
and
what
type
they
are.
2-1

COLT 286 SERVICE MANUAL
’
t
these
options:
Here
Diskette
1:
Predefincd
entries:
None,
360
Kb
5.25,
1.2
Mb
5.25,
720
Kb
3.5,
1.44
Mb
3.5.
The
floppy
drive
in
your
COLT
286
is
always
considered
Diskette
1.
Since
COLT
286
is
equipped
with
a
high
density
(1.44
Mb)
drive,
select
1.44
Mb
3.5
for
Diskette
1.
.
:
Predefined
entries:
None,
360
Kb
5.25,
1.2
Mb
5.25,
720
Kb
3.5,
1.44
Mb
3.5.
Ieyouhave
not
installed
a
second
floppy
drive
in
your
COLT
2886,
select
None
for
Diskette
2.
If
you
have
installed
a
second
floppy
drive,
select
whichever
drive
type
(360
Kb
5.25,
1.2
Mb
5.25,
720
Kb
3.5,
1.44
Mb
3.5)
applies
to the installed drive.
Setting
the
Hard
Disk
Drive
Options
Hard
Disk
1
and
Hard
Disk
2,
the
next
two
options
in
the
Setup
utility,
define
how
many
hard
disk
drives
are
available
and
what
kind
of
hard
disk
drives
they
are.
Hard
disk
drives
are
identified
by
a
pre-assigned
Drive
Type
(1,
2,
etc.).
This
number
tells
the
COLT
286
the
drive
manufacturer
and
capacity.
fl Commodore Setup Utility N
Fr Default Systen Speed 12 MHz dauhaee
. 6 MHz Hard Disk 1/0 DISABLED Ij_2one S
Diskette On Board Mouse ENABLED Peg nn
Diskette 2
HardDi On Board COM 3FEH ST SCHB
rdDiskl
HardDisk2 On Board LPT SBCH | 1023 S9B
Video Press F2 to return to sain screen B2 a w
Coprocessor ro
Base Menory 640 KB 2 73 5 17 300 733 30MB
Extended Nenory 000 KB 23 06 4 7 0 336 108
Base nenory found: 640 KB 24 805 4 26 0 820 40UB
Extended zneaory found: 000 KB 2 1 ji > o o um
Use f, Jtoselect itens 2 625 527 0 87 AlM
Bande - to select predefined 28 %5 5 17 0 1000 40MB
293 %5 10 17 l MB
Use <PgDn> to view more hard disk 3 782 : 28 : on Sn
types a 0000 0 2%“
Press <Esc> to abort SETUP 32 000 0 0 0m
Press <End> to exit and update
(Press
Fl
for
secondary
SETUP
window
-)
FIGURE 2. SETUP UTILITY PULLDOWN MENU FOR HARD DISK DRIVE TYPE
Here’s how to define your hard disk configuration:
Hard Disk 1:
Your
COLT
286
comes
equipped
with
a
20
MB
hard
disk
drive.
This
drive
is
always
considered
Hard
Disk
1.
The
Drive
Type
for
this
drive
is
shown
on
a
sticker
located
on
the
back
of
your
System
Unit.
Find
this
number
and
type
it
in
after
Hard
Disk
1.
"
The
COLT
286
Setup
utility
includes
a
menu
of
hard
disk
drive
types
with
their
individual
ID
numbers.
You
can
page
through
the
menu
by
pressing
the
PgDn
key.
For
example,
the
opening
Setup
screen
in
Figure
1
lists
drive
types
1
through
16.
If
you
press
PgDn,
the
Setup
screen
will
be
as
shown
in
Figure
2
with
drive
types
17
through
32
listed.
Hard
Disk
2:
This
option
is
not
supported
by
the
onboard
controller.
Other
Setup
Options
on
the
Main
Setup
Screen
Video:
Tells
system
what
the
default
video
is.
Factory-set
default
is
special.
This
will
not
change
even
if
the
EGA
Wonder800
+
Card
setting
changes.
To
change
the
card
setting,
see
the
EGA
Wonder800
+
User’s
Guide.
Coprocessor:
Tells
system
if
an
80287
Numeric
Coprocessor
(NCP)
is
installed.
Factory-set
default
is
zone.
Select
Yes
if
you
have
installed
an
80237
Numeric
Coprocessor.
Base
memory:
Lets
you
customize
base
memory
for
specific
applications.
Extended
Memory:
Disabled.
2-2

COLT 286 SERVICE MANUAL
Using
the
Secondary
Setup
Window
|
Notice
the
popup
window
shown
at
the
top
of
Figure
2.
This
menu
is
known
as
the
secondary
Setup
window.
You
can
access
this
window
by
pressing
the
Fl
key.
You
can
return
to
the
main
Setup
window
by
pressing
the
F2
key.
The
secondary
window
provides
an
easy
way
to
change
a
number
of
system
parameters
that
are
set
at
startup
by
the
COLT
286’s
AUTOCONFIG
feature.
The
secondary
Setup
window
values
shown
in
Figure
2
are
the
default
values
normally
present
at
system
startup.
The
following
list
shows
all
the
possible
values
for
the
menu
items;
the
default
values are underlined:
Default
System
Speed
(6/8/12
MHz)
6
MHz
Hard
Disk
//O
(Disabled/Enabled)
On
Board
Mouse
(Enabled/Disabled)
On
Board
COM
(3F8H/2F8H/OFF)
On
Board
LPT
(@BCH/378H/278H/OFF)
Just
as
with
the
main
Setup
screen
menu,
when
you
are
in
the
secondary
Setup
window
you
can
move
to
an
item
by
using
the
up
and
down
cursor
keys,
and
you
can
set
the
value
of
the
item
by
using
the
left
and
right
cursor
keys.
However,
you
cannot
use
the
Esc
or
End
keys
while
you
are
in
the
secondary
window;
before
you
can
use
these
keys
you
must
first
return
to
the
main
Setup
screen
by
pressing
the
F2
key.
The
Default
System
Speed
item
allows
you
to
select
whatever
system
speed
best
suits
the
particular
hardware/software
configuration
of
your
COLT
286.
For
instance,
if
you
are
using
some
older
software
programs
or
if
you
have
installed
a
slow
speed
(6
MHz)
Numeric
Coprocessor,
these
may
not
run
at
all
or
may
be
unreliable
at
a
system
speed
of
12
MHz.
In
such
cases
you
can
simply
select
the
6
or
8
MHz
clock
speed
as
the
Default
System
Speed.
Note that the 6 MHz Hard Disk I/O value is normally disabled to allow for the fastest possible data transfer to and
from the hard disk. You should not have to change this setting unless you are using a hard disk that cannot support
high speed data transfer.
You can use the secondary Setup window to enable or disable the on board mouse and to select the serial port (COM)
and the parallel port (LPT).
SETTING THE MICROPROCESSOR CLOCK SPEED
The 80286 microprocessor in the COLT 286 is capable of running at three different clock (i.e., processor or CPU) speeds:
o Standard speed = 6 Mhz
° Turbo speed = 8 Mhz
° Double speed = 12 Mhz
Unless you have changed the Default System Speed item in the secondary Setup window, the COLT 286 is pre-set to
run
to
double
speed
(12
MHz)
whenever
it
is
booted.
You
can
switch
between
the
clock
speeds
during
a
session
by
using
special
key
combinations
or
by
using
the
ATSPEED
command.
(NOTE:
If
you
reboot
the
COLT
286,
the
system
speed will revert to the default speed specified in the Setup utility. You can reset the default speed by using Ctri-Alt-
Esc
to
access
the
Setup
utility
and
then
using
F1
to call
up
the
secondary
Setup
window.)
To
set
the
clock
speed
from
the
keyboard,
use
these
key
sequences:
°
CTRL-ALT-S
for
standard
speed
(6
MHz)
°
CTRL-ALT-T
for
turbo
speed
(8
MHz)
°
CTRL-ALT-D
for
double
speed
(12
MHz)
Note: Some software may require that you select standard or turbo speeds for normal operation.
To set the clock speed using the ATSPEED command, first make sure the MS-DOS prompt is showing on the screen.
Then
type
the
word
ATSPEED,
followed
by
aspace,
a
dash
(—),
and
then
a
letter
(S,
T
or
D)
denoting
the
desired
speed.
For
instance,
if
you
are
in
standard
speed
and
you
want
to
change
to
turbo
speed
(8
MHz),
type
the
following
and
press
Enter:
ATSPEED —T
2-3

COLT 286 SERVICE MANUAL
COLT
286
VIDEO
MODES
The
EGA
Wonder800
+
card
in
the
COLT
286
is
a
high
performance
EGA
graphics
card
from
ATI
Technologies
Inc.,
a
recognized
leader
in
the
video
display
card
field.
Offering
total
flexibility,
the
EGA
Wonder800
+
can
display
all
of
the
major
IBM
PC
software
and
hardware
stan-
dards
—
EGA,
CGA,
MDA
and
Hercules
—
on
any
of
the
major
monitor
types
—
Enhanced
Graphics,
RGB
Color,
TTL
Monochrome
and
Multifrequency
monitors.
The
EGA
Wonder800
+
is
100%
hardware
compatible
at
the
BIOS
and register levels.
There
are
no
switches
or
jumpers
to
set
on
the
EGA
Wonder800
+;
special
software
automatically
configures
your
system
at
bootup.
The
EGA
Wonder800
+
software
utilities,
ESETUP
and
ECONFIG,
allow
the
user
to
easily
change
the
computer
selected
default
video
configuration.
.
ESETUP
ESETUP
is
used
to
configure
the
onboard
EEPROM.
The
setup
information
is
retained
even
after
the
power
is
turned
off.
It
is
also
used
to
change
or
store
the
default
information
used
by
the
EGA
Wonder800
+.
It
is
only
necessary
to
use
ESETUP
in
the
following
situations:
e
To
change
the
default
setup
video
mode.
e
To
specify
default
monitor
selection
on
power-up.
To start ESETUP, type at the DOS prompt:
C>ESETUP <Enter>
A menu like the following will be displayed:
ATI TECHNOLOGIES INC ATI TECHNOLOGIES INC A
TI TECHNOLOGIES INC ATI TECHNOLOGIES INC AT MONITOR
I TECHNOLOGIES INC ATI TECHNOLOGIES INC ATI SELECTION
© COPYRIGHT 1989
EGAWONDER800+ ADVANCE SETUP PROGRAM
ESETUP VERSION xxx
. POWER UP MODE SELECTION
[DJ MDA MONO GRAPHICS 720X348
[E) MDA MONO GRAPHICS 640X400
[fJ}] ADJUST TTL MONOCHROME GRAYSCALE
[G) EXIT AND SAVE CONFIGURATION
Monitor detected
EGA
Use
<
1}
>
or
<
letter
>
and
<
ret
>
to
select
option,
<
eac
>
to abort.
NOTE:
Because
of
ongoing
product
improvements,
EGA
Wonder800
+
menus
and
features
may
not
be
exactly
as
shown.
See
the
EGA
Wonder
800
+
User’s
Guide
and
the
software
README
files
for
the
most
current
information.
The options in the ESETUP menu can be selected by typing in the letter to the left of the selection and then pressing
ne
A
Key.
For
a
full
description
of
the
ESETUP
software,
including
the
individual
options,
see
the
EGA
Wonder800
'ser’s Guide.
ECONFIG
ECONFIG
is
a
manu-driven
used
to:
©
Change
the
current
video
mode
to
a
different
mode.
.
Automatically
turn
your
screen
display
off
during
long
periods
of
inactivity.
ECONFIG
is
available
on
your hard
disk
drive
and
on
one
of
the
EGA
Wonder800
+
software
diskettes.
2-4

COLT 286 SERVICE MANUAL
To
start
ECONFIG,
type
at
the
DOS
prompt:
C>ECONFIG
<enter>
ATI
TECHNOLOGIES
INC
ATI
TECHNOLOGIES
INC
A
EENURRER
m
anrretetsene
nie
A |
[HERE
G
I
TECHNOLO
©
COPYRIGHT
1989
SELECTION
ER800+
ADVANCE
CONFIGURATION
Do
EGAWOND
PROGRAM
COLOR
SETUP
VERSION
OX
MONO
SELECTION
KEYWORDS
a ER
MDA
MONO
TEXT
720x348
MDA
MDA MONO GRAPHICS 720x340 H720
MDA MONO GRAPHICS 640X400 7 H640
132x265 25
132x44
44
SCREEN SAVE SAVE
EXIT
Current configuration Monitor detected
EQA in ce80 EGA "
Use <1}> or < letter > and < ret > to select option,
<esc > to abort.
As with ESETUP, each of the options in ECONFIG can be selected by typing in the letter to the left of the selection
and then depressing the Enter key. As you get familiar with the operation of ECONFIG, you can bypass the menu
completely by typing:
C>ECONFIG[KEYWORD] <Enter>
The keywords are indicated on the right hand side of the screen: EGA, CGA, MDA, H720, H640, 25, 44 or SAVE.
For a full description of the ECONFIG software and options, see the EGA Wonder800 + User’s Guide.
AUTOCONFIG"
AUTOCONFIGuration is a unique feature of the Commodore PC personal computers like the COLT 286, allowing
the computer to automatically sense additional peripheral devices plugged into the expansion bus. Once these addi-
tional devices are detected, the resident peripherals on the COLT 286 motherboard are adjusted so as not to conflict
with expansion peripherals. The AUTOCONFIG" feature can prevent hardware damage to peripherals and mother-
board, as well as ease the installation of expansion cards.
VIDEO
The video configuration process for the COLT 286 is handled by the EGA Wonder800 + video system. See the EGA
Wonder800
+
User’s
Guide
for
full
details
on
the
COLT
286
video
configuration.
Serial Port (COMn;)
Before
the
onboard
serial
port
is
enabled
a
scan
of
the
two
standard
COMn:
hardware
locations
is
made.
If
serial
hardware (serial card/modem) is found operational, possible bootup message(s) may be:
EXPANSION COM at 03F8h
and/or
EXPANSION COM at 02F8h
If
both
available
COM:
addresses
are
Occupied
by
expansion
boards,
then
the
onbard
serial
port
will
not
be
enabled.
The
onboard
serial
port
will
be
configured
and
tested
at I/O
address
03F8h
if
no expansion
COM:’s
are
found
and
will
be
configured
and
tested
to
the
unused
COM:
address
if
only
one
expansion
COM:
is
found.
If
the
onboard
serial
port
is
configured
and
tested
successfully
a
message
will
be
output
during
bootup:
ONBOARD
COM
at
03F8h
or
ONBOARD
COM
at
02F8h
2-5

COLT 286 SERVICE MANUAL
Before
a
Parallel
por
is
enabled,
a
scan
ofthe
three
standard
LPTn:
hardware
locations
is
made.
If
parallel
hardware
(e.g., a printer
card)
is found
operational,
possible
bootup
message(s)
may
be:
EXPANSION
LPT
at
0378h
and/or
EXPANSION
LPT at 0278h
and/or
EXPANSION
LPT
at 03BCh
If
all
available
LPT:
addresses
are
occupied
by
expansion
boards,
then
the
onboard
parallel
port
will
not
be
enabled.
The
onboard
parallel
port
will
be
configured
and
tested
at
I/O
address
03BCh
if
no
expansion
LPT:’s
are
found
and
will
be
configured
and
tested
to
the
unused
LPT:
address
if
two
expansion
LPT:’s
are
found.
If
only
one
expansion
LPT:
is
found,
the
onboard
parallel
port
will
be
enabled
to
the
first
available
I/O
address
when
searching
in
the
following
sequence:
03BCh,
0378h,
0278h
If
the
onboard
parallel
port
is
configured
and
tested
successfully,
a
message
will
be
output
during
bootup:
ONBOARD
LPT at
03BCh
or
ONBOARD
LPT
at 0378h
or
ONBOARD
LPT
at
0278h
Mouse Port
A check is made for a standard Microsoft Bus Mouse. If it is found in the I/O channel then the onboard Microsoft
compatible mouse hardware is never enabled. The following message will appear during bootup:
EXPANSION MOUSE at 023Ch
If no expansion mouse is found the onboard mouse is enabled and tested. If the mouse is operational then the follow-
ing message will appear during bootup:
ONBOARD MOUSE at 023Ch
NOTE: The onboard Mouse hardware is enabled/tested independent of the presence of the actual mouse. The bootup
messages will appear even if the Commodore PC Mouse Kit is not attached.
80287 Numeric Coprocessor
A test is made for the presence of an 80287 Numeric Coprocessor during bootup. If an 80287 is detected the following
message will be output:
80287 Numeric Coprocessor
USING
AN
80287
NUMERIC
COPROCESSOR
The
Commodore
COLT
286
personal
computer
comes
equipped
with
a
40-pin
socket
(U302)
for
installation
of
an
80287
Numeric
Coprocessor
(NCP).
When
used
with
software
or
drivers
designed
to
make
use
of
its
abilities,
the
NCP
enhances
the
COLT
286’s
ability
to
process
floating
point
mathematics,
integer
math
and
trancendental
functions.
Many
language
compilers
(e.g.,
‘‘C’’)
have
libraries
available
that
support
the
use
of
an
NCP.
80287
NCPs
are
available
in
the
following
speeds:
5,
6,
8
and
10
MHz.
The
units
are
downwardiy
compatible
only!
This
means
that
a
10
MHz
part
will
function
properly
if
your
COLT
2886
is
running
at
6
or
8
MHz,
but
a
6
MHz
part
will
NOT
function
at
12
MHz.
Asa
rule
the
higher
the
speed
of
an
NCP,
the
more
expensive
and
harder
to
find
that
NCP
will
be.
The
8
MHz
802875
are
most
readily
available
and
are
reasonably
priced.
To
operate
your
COLT
286
at
clock
speeds
of
6,
8
and
12
MHz
with
an
NCP,
an
80287-8
or
80287-10
is
required.
INSTALLING
THE
OPTIONAL
COMMODORE
910,
915
AND
920
FLOPPY
DRIVES
In
addition
to
following
the
general
installati
. on instructions given in the manuals for the Commodore 910 and 920
floppy drives,
the
user
must
also
perform
the
specific
procedures
for
COLT
286
installation
described
below.
2-6

COLT 286 SERVICE MANUAL
Commodore
910
Floppy
Drive
To
install
the
Commodore
910
3.5
inch
720Kb
drive
as
Drive
B:
in
the
COLT
286,
the
user
must
do
the
following:
e
Set
the
drive
select
jumper
to
position
1.
©
The
M
jumper
should
be
in
position
5.
e
The
R-D
jumper
should
be
in
position
6.
e
The
first
time
you
power
up, use
the
Setup
utility
to
identify
your
second
drive
(Diskette
2
on
the
menu)
as
a
720Kb
3.5
drive.
Commodore 920 Floppy Drive
To
install
the
Commodore
920
5.25
inch
360Kb
floppy
drive
as
Drive
B:
in
the
COLT
286,
the
user
must
do
the
following:
©
Set
the
drive
select
jumper
to
position
1.
®
Cut
JP6
(located
on
the
bottom
side
of
JP1)
in
half.
e
The
first
time
you
power
up, use
the
Setup
utility
to
identify
your
second
drive
(Diskette
2
on
the
menu)
as
a 360Kb 5.25 drive.
Commodore 915 Floppy Drive
No special procedures are required to install the Commodore 915 3.5 inch 1.44 Mb as Drive B:; just follow the instruc-
tions in the manual. The first time you power up, use the Setup utility to identify your second drive (Diskette 2 on
the menu) as a 1.44Mb, 3.5 drive.
USING 720 KB FLOPPY DISKS ON THE COLT 286 SYSTEM
The floppy disk drive (Drive A:) is designed to make full use of 3.5 inch, double-sided high-density disks (DS/HD
disks), which can be formatted to store ukp to 1.44 MB of information. This drive can also read and write the 3.5
inch, double-sided double-density disks (DS/DD disks), which can be formatted to store 720 KB of information.
USING THE SINGLE FLOPPY DRIVE AS TWO DRIVES
Even though the standard COLT 286 configuration includes only one floppy disk drive, you can still type MS-DOS
commands as if you had two floppy drives in the system. Just think of the single drive as being two drives — Drive
A: and Drive B:. However, instead of A: and B: representing physical drives, they represent disks.
SPECIAL KEYBOARDS
The COLT 286 MS-DOS software allows you to select any of the following keyboards, in addition to the U.S. keyboard.
Just type the appropriate KEYB xx command at the MS-DOS prompt and press ENTER. In KEYB xx, xx is one of
the following two-letter codes:
Code
Keyboard
Command
DV
Dvorak
keyb
dv
FR
France
keyb
fr
GR
Germany
keyb
gr
IT
Italy
keyb
it
SP
Spain
keyb
sp
UK
United
Kingdom
keyb
uk
You should load only one keyboard program after starting MS-DOS. You can switch from the KEYB program to
the
default
(United
States)
keyboard
format
at
any
time
by
pressing
CTRL-ALT-Fl.
You
can then
return
to
the
memory-
resident
keyboard
program
by
pressing
CTRL-ALT-F2.
If
you
include
the
appropriate
KEYB
command
in
your
AUTOEXEC.BAT
file,
the
correct
keyboard
assignment
will
be
made
automatically
whenever
you
boot
MS-DOS.
For
More
Information
About
the
Keyboard...
For nor information about using the COLT 286”s keyboard, see the KEYB command description in the MS-DOS Com-
mands
chapter
of
the
MS-DOS
User’s
Reference.
Also
see
the
user’s
manuals
for
your
software
programs.
2-7

COLT
286
SERVICE
MANUAL
000000
k
640K
RAM
09FFFF
0A0000
VIDEO
RAM
0BFFFF
0C0000
VIDEO
BIOS
OCTFFF
0C8000
OPTION
ROMS
1MB
OEFFFF
OF0000
INTERNAL
USE
OF8000
32K
AT
ROM
BIOS
OFFFFF
100000
I
EXTENDED
MEMORY
—.
—_
15MB
-
——
Y
COLT
286
MEMORY
MAP
2.8

COLT 286 SERVICE MANUAL
SECTION 3
TROUBLESHOOTING GUIDE
TECHNICAL SERVICE NOTES
WARNING: COLT 286 PRINTED CIRCUIT BOARD CONTAINS CMOS CIRCUITRY, USE STATIC
PRECAUTIONS WHEN HANDLING OR SERVICING THIS PRODUCT.
IMPORTANT:
COLT 286 PCB’S RETURNED FOR CREDIT MUST BE SHIPPED IN AN ANTI-STATIC BAG,
AVAILABLE THROUGH THE COMMODORE PARTS DEPT. ANY PCBS RETURNED FOR CREDIT
BY SERVICE CENTERS WHICH ARE NOT PACKAGED CORRECTLY WILL BE SENT BACK TO
THE SERVICE CENTER AND NO CREDIT WILL BE ISSUED.
°COLT 286 HARD DRIVES RETURNED FOR CREDIT MUST BE INSERTED IN AN ANTI-STATIC BAG
AND PACKED IN A COMMODORE SPECIFIED HIGH DENSITY FOAM SHIPPING BOX, BOTH
AVAILABLE THROUGH THE PARTS DEPT. FAILURE TO DO SO WILL VOID WARRANTY.
COMPONENT REPAIR:
COLT 286 MAIN BOARD IS A MULTI-LAYERED PCB ASSEMBLY. COMPONENT REPAIR BEYOND
THE SOCKETTED CHIP LEVEL RESULTING IN NON-REPAIRABLE DAMAGE WILL VOID WARRAN-
TY. USE STATIC PRECAUTIONS WHEN SERVICING THIS PCB ASSEMBLY.

10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
COLT 286 SERVICE MANUAL
TROUBLESHOOTING
ERROR
MESSAGES
Troubleshooting Guide
Error Messages
. DMA 1 error
. DMA 2 error
. Interrupt controller 1 error
Interrupt controller 2 error
. PIO error
. Parity error
. Real time clock is not working
. Illegal shutdown code in CMOS
. Virtual Mode CPU error
Parity error on main circuit board
Parity error on expansion bus
Non-recoverable error-Processor halted
Press Fi key to continue
Battery Failure
Base memory configuration error
Extended memory configuration error
Floppy 0 configuration error
Floppy 1 configuration error
Coprocessor
(80287)
configuration
error
The
realtime
clock
has
not
been
initialized
Keyboard
Key
switch
is
off.
Turn
it
on
to
continue
Boot
failure,
check
disk
and
hit
any
key
to
try
again
Customer Response
See your dealer
See your dealer
See your dealer
See your dealer
See your dealer
See your dealer
See your dealer
See your dealer
See your dealer
See your dealer
See your dealer
See your dealer
Press Fl key
Run Setup Utility/See your dealer
Run Setup Utility
Run Setup Utility
Run Setup Utility
Run Setup Utility
Run Setup Utility
Run Setup Utility
Check keyboard
Turn keylock on
Check for non-MS-DOS disk in
Service POD Test (H)
Test OB
Test 0C
Test OD
Test 0E
Test OF
Test 10
Test IE
Test 02
Test 26
Misc
Misc
Misc
Misc
Test 11
Test 17
Test 18
Test 1A
Test 1A
Test ID
Test IE
Test 14
Misc
Drive A:; run Setup Utility

COLT 286 SERVICE MANUAL
POWER
ON
DIAGNOSTICS
COLT
286
Trouble
Shooting
—
Section
3
The
Commodore
80286
ROM
bios
contains
a
“Power
on
Diagnostic’’
program
which
tests
the
functions
of
hardware
and
checks
the
configuration
prior
tO
passing
control
to
the
operating
system.
The
number
of
the
test
routine
being
run
is
passed
to
addr
03
78
(H)
prior
to
the
start
of
each
test
section.
The
80286
processor
is
initialized
by
the
‘“RESET’”’
signal.
Refer
to
RESET
description
in
IC
pinout
section,
note
that
“VCC’”
and
“‘CLK”’
to
CPU
must
be
correct
and
‘“HOLD’’
must
not
be
active
for
34
ticks
from
leading
edge
to
trailing
edge
of
initial
reset.
RESET
will
terminate
all
instruction
execution
and
local
bus
activity
until
it
is
negated.
Prior
to
fetching,
decoding
and
executing,
the
first
instruction,
located
at
physical
address
FF
FF
FO
(H),
the
80286,
in
real
address
mode,
pro-
cesses
some
micro
code
located
in
its
internal
ROM,
this
takes
about
38
ticks.
Test 01 (H) 0000 0001 (B)
The
first
test
performed
by
the
power
on
diagnostic
checks
the
8088
flags,
the
arithmetic
logical
unit,
and
the
CPU
registers.
If
a
failure
is
detected
in
Test
01,
a
“‘HALT’”’
instruction
is
executed.
This
will
stop
program
execution
and
prevent
the
CPU
from
using
the
local
bus.
The
80286
can
be
forced
out
of
the
halted
state
by
“RESET”,
‘‘NMI”
or
“INTR’’
(when
“INTR”
is
used
for
RESTART,
the
interrupt
enable
bit
of
flag
register
must
be
on
(set
to
1),
and
the
effective
address
computed
from
CS:IP
will
point
to
the
next
instruction
after
the
halt
instruction).
***Failure in test Ol indicates defective 80286. _
Test 02 (H) 0000 0010 (B)
This routine checks to see if a ‘SHUTDOWN’’ has occurred. A shutdown can indicate a severe error which would
prevent the CPU from further processing.
NOTE: A halt or shutdown condition is signaled externaily, by the 80286 as a bus operation. Low states on SO, SI’,
COD/INTA’, and a high state on M/IO’ indicate a halt or shutdown. The state of address line 1 will indicate
which condition, Al high is halt, Al low is shutdown. \
After the test number is moved to the parallel port a check for keyboard reset is conducted and the program branches
to test 04 (H) if it has.
The check for shutdown begins by examining the 8242 keyboard controller status port. In all ten shutdown conditions
are tested, of these, three unexpected shutdown conditions, numbers 6, 7 or 8, any one of which if true, will generate
the console message:
“legal Shutdown Code in CMOS’”
NOTE: Branch information for shutdown routines are stored in CMOS memory. The shutdown command is sent to the
8242, the UPI status port, which will halt the CPU. Return depends on the shutdown code in CMOS memory.
An error code, F6, F7 or F8, (HEX) is sent to the parallel port before calling the display routine which generates
the above message.
In
real
address
mode
a
shutdown
could
occur
under
the
following
conditions:
Interrupt
number
8,
interrupt
number
13,
or
a
““CALL
INT”
or
““PUSH”
instruction
which
wraps
stack
segment
when SP is ODD.
Routines
also
perform
valid
shutdowns
to
exit
protected
mode.
During
these
the
DMA
page
register
will
be
initialized
and interrupt control words (ICW) 1, 2, 3 and 4 will be reinitialized. Other routines within the test enable ““NMI’”,
parity and set the I/O check bit.
***Failures
in
test
02
could
indicate
problems
on
the
local
bus,
or
expansion
bus.
This
would
include:
80286,
FE3000,
FE3010,
or
any
third
party
cards.
Test 03 (H) 0000 0011 (B)
Eprom
checksum
test
verifies
contents
of
eprom
by
adding
bytes
and
checking
for
result
of
zero.
A
compensation
byte
is
factored
into
the
addition
to
make
the
sum
zero.
Detection
of
an
error
results
in
a
halt
condition
and
would
invalidate
tests
01
and
02.
***Failure
in
test
03
indicates
defective
ROM.
3-2

COLT 286 SERVICE MANUAL
Test 04 (H) 0000 0100 (B) .L . . ,
Test 04 checks the DMA page registers by writing and reading bits starting at address 80 (H).
***Eailure
in
test
04
indicates
possible
defective
FE3010,
or
local
bus.
Test
05
(H)
0000
0101
(B)
,
Timer
1
and
timer
2
are
checked
for
correct
operation.
Interrupts
are
masked
off
during
the
test.
***Failure
in
test
5
indicates
possible
defective
FE3010.
Test
06
(H)
0000 0110
(B)
Memory
refresh
test.
Timer
and
DMA
are
setup
t0
initiate
refresh
cycles
every
15.1
microseconds.
Size
of
virual
memory
is calculated.
.
***Failure
in
test
06
indicates
possible
FE3010,
Refresh
logic
or
memory
problem.
Test 07 (H) 0000 0111 (B)
Test
07
checks
the
8242
keyboard
controller
by
writing
and
reading
the
keyboard
buffers.
***Failure
in
test
07
indicates
possible
defective
8242
or
associated
circuitry.
Test 08 (H) 0000 1000 (B)
Test
08
writes
and
reads
the
first
128K
of
RAM
and
verifies
block
size
is
128K.
First
pass
writes
addresses
into
data,
the second pass writes the complement of the address into data. Memory is cleared after test. The battery status is
also confirmed in test 08.
***Fajlure in test 08 indicates possible defective RAM or RAM logic.
Test 09 (H) 0000 1001 (B)
Test and configure video. A search is made to determine if MDA, CGA or a special video adapter is configured, if
not the onboard VGA is enabled and a callto VGA bios is executed. The dip switches are read to determine the default
video mode.
NOTE: The mode register setting in the 5720 controls the reset signal to the onboard VGA controller chip. If no special
video adapters are found on the expansion bus then *“NOVID’”’ from the 5720 to the PVGA is negated.
On completion of this test the title and copyright message are displayed.
Test 0A (H) 0000 1010 (B)
Test RAM from 128K to 640K. A display message is generated indicating that the base RAM of 128K, Test 08, is OK.
Blocks of 128K, starting at 128K are then tested by writing, reading and verifying RAM. The first pass writes addresses
to data, that is, the address which defines the physical location is also used as the bit pattern that is being written.
The second pass writes complement of address into data.
The test displays results in blocks of 128K to the console each time a 128K boundary is reached.
At completion of the onboard memory test the CPU is placed in virual mode and a test for virtual memory (over
1 MEG) is started.
NOTE: See test 26 (H).
***Failure
in
test
OA
indicates
a
defective
RAM.
Test OB (H) 0000 1011 (B)
DMA
controller
#1
register
check.
NOTE: Error messages beginning with this test appear in the COLT 286 Operators Guide.
Four
current
address
registers
(16
bits
wide,
each)
and
four
current
word
count
registers
(16
bits
wide,
each)
for
each
of
the
four
DMA
channels
are
written
to
and
read
from
to
verify
operation.
A
failure
in
test
OB
will
generate
the
following
display
on
the
console:
“DMA
1
error”
The
beeper
will
sound,
and
a
halt
instruction
will
be
executed.
***Failure
in
test
OB
indicates
A
defective
FE3010.
3-3

COLT
286
SERVICE
MANUAL
Test
0C
(H)
0000
1100
(B)
d
functional
8237
containing
f
t
address
registers
(16
bits
wide
#2
register
check.
The
second
function:
containing
four
current
address
registers
i
’
eh)
sontrolle
urrent
word
count
registers
(16
bits
wide,
each)
within
the
FE3010
are
written
to
and
read
from
t0
verify operation. ,
Successful
completion
of
the
test
OC
will
set
the
modes
for
DMA
channels
0
through
3
and
enable
cascading
by
chan-
nels 4, 5 and 6 (DMA |).
A
failure
in
test
0C
will
generate
the
following
display
on
the
console:
“DMA 2 error”
The
beeper
will
sound,
and
a
halt
instruction
will
be
executed.
***Eailure
in
test
OC
indicates
a
defective
FE3010.
Test OD (H) 0000 1101 (B)
Interrupt
controller
#1
test.
Patterns
are
written
to,
and
read
from
the
interrupt
mask
register
(IMR)
which
controls
the interrupt
request register (IRR).
A
verification
is
made
that
no
interrupts
can
occur
if
*‘IMR”
is
set
to
FF
(H).
A
vector
is
initialized
to
a
temporary
interrupt
service
routine
in
the
event
of
a
failure.
A
test
for
correct
timer
0
interrupt
is
also
made.
A
failure
in
test
OD
will
generate
the
following
display
on
the
console:
““Interrupt
controller
1
error”
The
beeper
will
sound,
and
a
halt
instruction
will
be
executed.
**+A
failure
in
test
OD
indicates
a
defective
FE3010.
Test 0E (H) 0000 1110 (B)
Interrupt controller #2 test. The second functional 8259 contained in the FE3010 is tested as in test OD, without timer test.
A failure in test OE will generate the following display on the console:
*Interrupt controller 2 error’”’
The beeper will sound, and a halt instruction will be executed.
***A failure in test OE indicates a defective FE3010.
Test OF (H) 0000 1111 (B)
Check peripheral in/out register. Write and read from PIO register.
A
failure
in
test
OF
will
generate
the
following
display
on
the
console:
“PIO
error’
The
beeper
will
sound,
and
a
halt
instruction
will
be
executed.
***A
failure
in
test
OF
indicates
a
defective
FE3010.
Test
10
(H)
0001
0000
(B)
RAM
parity
test.
Blocks
of
RAM
are
written
to
and
read
from,
parity
check
for
odd
parity
is
made.
Parity
disabled
after
successful
test.
NOTE:
COLT
286
does
not
use
parity,
third
parity
boards
that
use
parity
will
enable
parity.
“NMI”
is
enabled
and
a
service
routine
for
a
parity
error
generates
the
following
console
message.
‘“Parity
error”
The
beeper
will
sound,
and
a
halt
instruction
will
be
executed.
***Failure
in
test
10
indicates
a
defective
RAM,
third
party
card,
NMI,
or
local
bus.
Test
11
(H)
0001
0001
(B)
Test
CMOS
clock
for
battery
failure
and
checksum
failure.
Beeper
will
sound
if
failure
is
detected.
Console
will
display:
.
“Battery
failure’’
or
“CMOS
checksum
failure”
or
both.
***Failure
of
test
11
indicates
a
defective
battery,
defective
oscillator,
or
M146818A.

COLT 286 SERVICE MANUAL
Test 12 (H) 0001 0010 (B)
This test is disabled. It is used only in manufacturing tests.
The beeper will sound for a set length prior to the start of test 13 (H). In a system which has passed all tests to this
point the beeper sound heard now would be the one heard in the power up routine.
Test 13 (H) 0001 0011 (B)
Setup interrupt controller and move vector tables to RAM. Vector addresses are fetched from top 8K module.
NOTE: Vectors for video were setup in test 09.
Master and slave interrupts are enabled at this point.
Test 13 does not create any error messages.
Test 14 (H) 0001 0100 (B)
Keyboard test. Functional test of the 8242 keyboard controller at U203. A test for a stuck key on keyboard is performed.
Check is made to see if key lock is locked.
A failure in test 14 will display the following error message on console:
“Keyboard error”
***Error indicates a defective 8242 controller or a defective keyboard.
Test 15 (H) 0001 0101 (B)
Test and configure the parallel port. Parallel port addresses are setup, reads and writes to ports are done. Set time out.
No error messages are generated by this test.
NOTE: PPC1 at U602 controls parallel output.
Test 16 (H) 0001 0110 (B)
Configure serial COMI and COM2 for 8250 at U604. Read serial interrupt ID, set number of serial channels.
No error messages are generated by this test.
Test 17 (H) 0001 0111 (B)
Configure memory less than 640K. Parity (for EXPANSION RAM) is enabled.
Memory was tested in test OA, and ‘CMOS STATUS” set. A check for a warm boot (ALT/CNTRL/DEL) is made
and a comparison of the old and new memory configuration is performed. If a memory size mismatch is detected,
the beeper will sound and the following non-fatal error message will be displayed on the console:
“Base memory configuration error”
The new configuration is stored.
***Check the settings for RAM size in the setup utility if you encounter this message.
Test 18 (H) 0001 1000 (B)
Configure memory over I megabyte (virtual memory). Check is made on address line 20, a low indicates virtual ad-
dress mode.
CMOS status is checked as in test 17, a memory size mismatch will sound the beeper and generate the following non-
fatal error message on the console:
“Extended memory configuration error”
The new configuration is stored.
**+Check the settings for RAM size in the setup utility if you encounter this message.
Test 19 (H) 0001 1001 (B)
Configure keyboard test. Setup keyboard buffers, enable keyboard interrupt and test if key switch is turned to the
on position.
If the key switch is off the following message will be displayed on the console:
“Key switch is off. Turn it on to continue.”
NOTE: You are in a loop until you turn on the key switch.
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