Commodore Plus 4 User manual

SERVICE MANUAL
MODEL PLUS 4 COMPUTER
Preliminary
OCT. 1984
PN-314001-04
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 © 1984 by Commodore Electronics Limited.
All rights reserved.

CONTENTS
Title
SPECIFICATIONS
OVERVIEW .......................................................................................................... .
PRODUCT PARTS LIST
......................................................................................... .
CASEWORK IDENTIFICATION
................................................................................ .
PCB LAYOUT ....................................................................................................... .
PCB PARTS LIST .................................................................................................. .
PCB SCHEMATIC DIAGRAMS ................................................................................ .
KEYBOARD MATRIX
............................................................................................. .
I.C. PINOUTS
FOR UNCOMMON CHIPS .................................................................. .
RF MODULATOR 251844 LAYOUT ........................................................................ .
251844 SCHEMATIC .................................................................. .
RF MODULATOR 251311 LAYOUT ........................................................................ .
251311 SCHEMATIC .................................................................. .
Page
1
2
3
3
4
5
7
7
9
11
11
12
12
iiiliv

PLUS 4 PRODUCT SPECIFICATION
MEMORY
64K RAM. 60K RAM User accessible for BASIC programs.
ROM
32K ROM Standard (includes operating system and BASIC interpreter) with 32K additional ROM con-
taining
the built-in productivity software.
MICROPROCESSOR
7501 Microprocessor - .89 or 1.76 MHz clock.
DISPLAY
40 Columns x 25 lines of text.
COLORS
1
28 Colors (16 colors; 8 luminance levels).
CHARACTERS
Upper &
lower case letters, numerals and symbols. Reverse and flashing charachters. All PET graphic
characters.
DISPLAY MODES
Text characters. High resolution graphics. Split screen text/high resolution graphics. Multicolor graphics.
RESOLUTION
320 x 200 Pixels
SOUND
2 Tone generators or 1 Tone and 1
white noise generator.
VOLUME
8 Volume levels
KEYBOARD
Full size
typewriter style design
KEYS
67 Keys total. 4 Cursor control keys. 4 Programmed (reprogrammable) function keys (up to 8 user
defined functions possible). Color control keys.
HELP key. Upper and lower case character set. Graphics
character set.
INPUTS/OUTPUTS
PLUS/4 MODEM (User) port. Serial port. ROM cartridge and parallel disk drive port. 2
Joystick ports.
C1531 Cassette drive interface port.
RF Output-channel 3 or 4. Video output-compositel
chrominance/luminance. Audio input/output. Power supply input.
1

PLUS 4 PRODUCT SPECIFICATION (Continued)
FEATURES
Built-in extended BASIC 3.5 -over 75 commands. Built-in Machine Language monitor -over 12
commands. Built-in graphics and sound commands. Screen window capability. Reset button (Warm
start). Built-in integrated
productivity software.
PERIPHERALS
C1551 Fast Disk drive, C1531 Datasette, MPS 802 Dot matrix printer, MPS 803 Dot matrix printer,
DPS 1101 Daisy wheel printer, C1802 color monitor.
OTHER PERIPHERALS
C1541 Disk drive, MPS 801 Dot matrix printer, C1702 color monitor.
PLUS 4 OVERVIEW
The Plus 4 system is based on the 7501 microprocessor, an HMOS version of the 6510. Video pro-
cessing is achieved
by the 7360 TED chip. 64K bytes of dynamic RAM are accomplished by 8 (64K
x
1) I.C.'s. (See page ). The system program is contained in 2 (16K x 8) ROMs. The system supports
up
to 128K x 8 of ROM banked in 16K sections. By software control, through the 7360, ROM can
be completely banked out and RAM banked in for a true 64K of RAM (minus 256 byte pages), allow-
ing
60,671 bytes available for BASIC.
Keyboard and
joystick scanning are accomplished by outputting the row data on the data bus while
addressing a particular register in the
TED chip. This will in turn cause the TED chip to latch the column
information.
A standard serial port supports serial bus peripherals such
as the 1541 disk drive and the various
serial printers. A cassette port is provided and the expansion port supports
ROM cartrdiges. TTL serial
ASCII is intended
to drive an RS-232 adapter.
2

TOP CASE ASSY
Top Case
Keyboard, 67 Key, KKR-I
Nameplate
Shield Clip, R
Shield Clip, F
BOTTOM CASE ASSY
Bottom Case
Foot, Self-Adhesive
Paper Shield
Shield Chip
Shield Plate
Insulation Sheet
ACCESSORIES
Users Manual
Power Supply
RF Cable
Switch Box
PARTS LIST
PLUS/4
C 251453-01
C 251501-01
C 251655-01
C 251855-01
C 251856-01
C 251454-01
C 950157-04
C 310156-01
C 310199-01
C 310197-01
C 310198-01
C 310196-01
C 310157
C 326189-02
C 904778-01
C - Commodore Stock Part
r'"
~
F I-
"'"
~.
~
~
i-'t"o'
Cc
I
BIO'IIIK!' !....,eag]
/,\
~
II
~../
(eJI
L&~....... II II UHUt UII III
)
a
Plus 4 Casework Identification
3

SEE NOTE 1
DETAIL C
CNl
MI
Jl
@D
FB'II
I·~; I FI!'1q
F852
8+
F!H7
FB5D
+8
FB51
:z
FM5
E
FB43
FB44
RI
FB55
~
FBM
FB51 A A
F~Z
Fel53
FB'IS
0
FB5"
FB4"
DETAIL A
SOLDER
3 PL
PCB
BEND LEGS - 2 PLS
BOTTOM VIEW FOR M1
5mm MAX
_oL-->""o----
PUT TO USE FB39
FB40
DETAIL C
REAR SIDE VIEW
SOLDERING
CARTRIDGE
GUIDE
~
I F1558 I
~
WRI~~
@ [ia:
IFBI51
I FBI'" I
CRle
t::]iLJ
+
0[!] ~ ~@D
IFBW I
~
<J ~@D
o~~
UI
~
(1'.50 )
@D@D
(1:.45 )
@D
~
~
.....--v--
---v-- ....--...r--
l"-
N
:::J
CONTACT
TERMINAL
@D
~
DETAIL A
SIDE VIEW "A-A"
OF CNS
<n
[]
{\J
;t
:::J
::l ::l
SOLDER
Y2
BARE~ ~
BUSS r----~~--~~~
WIRE .L..----..----r---( PCB
DETAIL E
>Jl
(\J
:::J
0
enS
SHIELD
BOX
U4
PUT TO USE FB27
<@I
US
Uz.
@D
DETAIL B
m:QJ
<@
~~I
~+
@D
@
~
~
~
~~
SHIELD
CAP
I. JUMPER SE:LECTIO.... FOR .. J7 "
'- OOES .... 'T I.lAT"TER FaR IJTSC (-Oil.
- SHORT FOR Go-PAL (·021.
-OPEN FOR I-PAL (,03).
@D
~
NOTES - UNLESS 01HE.RWIS~ SPE:ClflE:D:
SOLDERING
FI
UI<.
U3
@D
@)
~ ~
(nc. ) (nil)
~ ~
JUMPER
WIRE
[Bi!:J
l <
Ul
[![I:J
@)
ve
~
!ELl
~+
( C.3'\)
r
~
0
DETAIL D
SOLDERING SIDE
@
DETAIL E
Plus 4 PCB Assembly
4

PARTS LIST -PLUS/4 PCB ASSEMBLY #310163-01
PLEASE NOTE: Commodore part numbers are provided for reference only and do not indicate the
availability
of parts from Commodore. Industry standard parts (Resistors, Capacitors,
Connectors) should
be secured locally. Approved cross-references for TTL chips,
Transistors, etc. will be available in manual
form through the Service Department
in November
of 1984. Unique or non-standard parts will be stocked by Commodore
and are indicated on
the parts list by a "C".
INTEGRATED CIRCUITS
U1
U2
U3
U4
U5
U6
U7
U8
U9-10
U11-18
U19
U20
U21
U22
U23
U24
U25
U26
7360 VLSI, Text Dislay (TED)
Sub: C 251535-01
8360 C 251535-02
7501 Custom Microprocessor
C 251536-01
6551A (Synertek) 901895-02
74LS08 901
521 -03
6529B Single Port Interface
74LS04
7406
555
74LS257
4164-2 D-RAM
7700-010 PLA
74LS139
74LS175
74LS27
2312B
ROM TED Basic
23128 ROM TED Kernal
C 251640-03
901521-02
901522-06
901523-01
901521-57
901505-01
C 251641-02
901521-18
901521-34
901521-22
C 318006-01
C
318005-04
23128 FUNCTION ROM, 3+ 1 LOW
C 317053-01
23128 FUNCTION ROM, 3+HIGH
C 317054-01
DIODES (Continued)
CR1
(cont.)
CR2
CR11-20
Bridge Rectifiers DBA20C
Sanyo
251026-03
Diode, Zener RD 6.8 EB 900927-01
Diode,
IN 914 Sub: 900850-16
Diode, IN 4148 Taping
251819-21 Sub:
Diode,
IN 4148 900850-01
RESISTORS -All values
are in ohms-1/4 W
5% unless noted otherwise.
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
4.7K
10K
470K
220K
18K
1.5K
470K
100K
1K
1K
12K
10K
1K
RESISTOR PACK
R14
R15
R16
R17
R18
R19
R20
R21
R22
R23
R24
R25
240
250
100K
1.5K
47K
100K
3K
1K
1K
1K
1K
1K
U27 6529B Single Port Interface
RP1, 2 3.3K, 6
PIN 902441-29
C 251640-03 RP3, 4 68, 8
PIN 4 ISOLATED 326149-06
TRANSISTORS
01-03
04
DIODES
CR1
2SC 1815
2SD
880
Tip 29A
2SD 1266
902693-01
902694-01 Sub:
902653-01 Sub:
902694-04
Bridge Rectifiers S2VB10 Sindengen
215026-01 Sub:
Bridge Recitifers DBA20B Sanyo
251026-02
Sub:
CAPACITORS
C1
C2
C3
C4
C5-C6
C7
C8
C9
C10
C11
Elect 0.1 J.tF 25V
Ceramic 0.1 J.tF 25V
Film 0.22 J.tF 100V
Film 0.22 J.tF 100V
Ceramic 0.22 J.tF 50V
Elect 2200 J.tF 16V
Elect 10 J.tF 1 6V
Ceramic 0.1 J.tF 25V
Trimmer 40 pF
Ceramic 22 pF 50V
900100-40
251075-06
900150-11
900150-11
900022-01
900101-33
900100-25
251075-06
251029-02
251070-14
5

PARTS LIST -PLUS/4
PCB ASSEMBLY
#310163-01 (Continued'
CAPACITORS (Continued' MISCELLANEOUS (Continued'
C12 Ceramic
220 pF 50V
Sub: FB2-14 Ferrite
bead 325563-01
251071-26 Sub: FB15-21 Ferrite bead 903025-01
Ceramic
220 pF 50V 900463-08 FB22-26,
C13 Ceramic
150 pF 50V
251071-24 FB28-38, Ferrite bead 325563-01
Sub: FB40
Ceramic
150 pF 50V 900462-41 FB41-58 Ferrite bead 903025-01
C14 Ceramic 0.1
p,F 25V 251075-01 FB59 Ferrite bead 325563-01
C15-C16 Ceramic 0.1
p,F 25V
251075-06 FB60 Ferrite bead 903025-01
C17-C18 Ceramic
10 p,F 16V 900100-25 FB61-63 Ferrite bead 325563-01
C19 Ceramic 0.01
p,F 25V 251075-01 FB64-65 Ferrite
bead 903025-01
C20 Elect
10 p,F 16V 900100-25
C21
Ceramic 0.1 p,F 25V 251075-06
EM1,2
EMI Filter 251842-01
C22 Elect
10 p,F 16V 900100-25
C23 Elect 1
p,F 16V
900100-16 CN1 Connector 4 PIN (power supply)
C24-C26 Ceramic 0.1
p,F 25V
251075-06 C 251614-01
C27 Elect
10 p,F 16V 900100-25 CN2 Connector 6 PIN DIN (serial bus)
C28-C29 Ceramic 0.1
p,F 25V 251075-06
C 903361-01
C30 Elect
10 p,F 16V 900100-25
CN3 Connector 7 PIN MINI DIN (cassette)
C31-C32 Ceramic 0.1
p,F 25V 251075-06 C 251616-01
C33-C40 Ceramic
0.22 p,F 25V 251075-07 CN4 Connector 50 PIN Female Edge
Sub: (exoab) C251630-01
Ceramic 0.22 p,F 50V 900022-01 CN5-6 Connector 8 PIN MINI DIN
C41-C51 Ceramic 0.1
p,F 50V 900020-06 (joy 1 & 2)
C 251259-01
Sub: CN7 Connector 8
PIN DIN (audio/video)
Ceramic 0.1
p,F 50V 9000010-01 325573-01
C100 Ceramic 0.1
p,F 50V 900010-20 CN8 Connector 18 PIN (keyboard)
C 251841-01
MISCELLANEOUS
L1 Noise Filter 251264-01
Y1
Crystal 14.31818 MHZ 251081-01
L2 Line Filter 906127-01
Sub: Sub: 251701-01
Crystal
14.31818 MHZ 251081-02 Sub:
Y2 Crystal
1.8432 MHZ 900555-02 L3,L3 Coil Inductor 1.2 uHpt 901152-01
Sub: 325570-01
SW1 Switch, Rocker C 251587-01
(PC Mount)
F1 Fuse 250V 1.5A 903556-18
SW2 Switch,
Push Button C 251260-01
Fuse Clip 906102-01
Cartridge Guide 310171-01
M1
RF Modulator C 251844-01 Shield
Box C310172-01
Sub: Shield
Cap C 310173-01
RF Modulator 251311-01
C - Commodore Stock Part
6