PROJECT 64 ETEXT
						COMMODORE 64 SERVICE MANUAL

                           Version 1.1 (Feb 1998)



						   Converted to etext by
                      Sami Rautiainen <devili@iki.fi>

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-------------------------------------------------------------------------------
~

								 SERVICE MANUAL
							   MODEL C64 COMPUTER

						  September 1985  PN-314001-02



					   Commodore Business Machines, Inc.
		   1200 Wilson Drive, West Chester, Pennsylvania 19380 U.S.A.

				Commodore makes no expressed or implied
				warranties with regard to the information
				contained herein. The information is made
				available solely on as is basis, and the
				entire risk as to quality and accuracy is
				within the user. Commodore shall not be liable
				for any consequential or incidental damages in
				connection with the use of the information
				contained herein. The listing of any available
				replacement 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 by any means, electronic, mechanical,
		photocopying, recording or otherwise, without the prior written
		permission of Commodore Electronics Limited.

		Copyright (C) 1985 by Commodore Electronics Limited.
		All rights reserved.












~
								  CONTENTS
																	   Page
	SPECIFICATIONS ..................................................	  1
	PRODUCT PARTS LIST ..............................................	  2
	BLOCK DIAGRAM ...................................................	  3
	CIRCUIT THEORY
		POWER SUPPLY ................................................	  4
		RESET LOGIC .................................................	  5
		CLOCK CIRCUITS ..............................................	  6
		I/O, RAM, EXPANSION LOGIC ...................................	  7
		RAM CONTROL LOGIC ...........................................	  8
		5 PIN VIDEO AND AUDIO OUTPUTS ...............................	  9
		8 PIN VIDEO AND AUDIO OUTPUTS ...............................	 10
		CASSETTE INTERFACE ..........................................	 11
		KEYBOARD, JOYSTICK & PADDLE INTERFACES ......................	 12
		SERIAL INTERFACE, USER PORT .................................	 13
	TROUBLESHOOTING GUIDE ...........................................	 14
	BOARD IDENTIFICATION ............................................	 17
	PCB ASSEMBLY #326298-01
		BOARD LAYOUT ................................................	 18
		PARTS LISTS ................................................. 19,20
		SCHEMATIC #326106 ........................................... 21,22
	PCB ASSEMBLY #260407-04
		BOARD LAYOUT ................................................	 23
		PARTS LIST .................................................. 24,25
		MODULATOR SCHEMATIC #251025 .................................	 26
		SCHEMATIC #251138 ........................................... 26,27
	PCB ASSEMBLY #250425-01
		BOARD LAYOUT ................................................	 28
		PARTS LIST .................................................. 29,30
		MODULATOR SCHEMATIC #251696 .................................	 31
		SCHEMATIC #251469 ........................................... 31,32
		PIN ASSIGNMENTS .............................................	 33














~
								  C64 COMPUTER

General description
				The "All Purpose" Commodore 64 us the complete computer for
				education, home or small business applications. Supported
				by quality peripherals and a full range of software, the
				Commodore 64 is perfect for the family. No other computer
				can offer such variety of uses and applications at such an
				affordable price.

Memory			64K RAM

ROM 			20K ROM Standard (includes operating system and BASIC
				interpreter)

Microprocessor	6510A Microprocessor - 1.02 MHz clock
				Compatible with the 6502

Display 		40 Columns X 25 lines of text

Colors			16 Background, border and character colors

Characters		Upper & lower case letters, numerals and symbols
				Reverse characters
				All PET graphic characters

Display modes	Text characters * High resolution graphics

Resolution		320 X 200 Pixels

Sprites 		8 independent sprites
				Each consists of 24 X 21 pixels and up to 4 colors
				Each independently expandable horizontally and vertically
				Collision detection for sprite to sprite and data to sprite
				collisions

Sound			6581 Sound Interface Device includes 3 independent tone
				generators - each with 9 octaves
				Each voice includes programmable ADSR generator (Attack, Decay,
				Sustain, Release) and control of sawtooth, triangle, square,
				variable pulse and noise waveforms
				Full filtering capabilities with low, high and band pass
				filters
				External sound input

Keyboard		Full size typewriter style design

~
Keys			66 Keys total
				2 Cursor control keys
				4 Function keys (up to 8 user defined/programmable functions
				possible)
				Upper and lower case character set
				Graphic character set

Inputs/Outputs	User port
				Serial port
				ROM cartridge port
				2 Joystick/paddle ports
				Video port C1530 Cassette drive interface port

Features		Built-in BASIC 2.0 - over 70 commands, statements and functions
				Full screen editor

Peripherals 	C1541 Disk drive
				C1530 Datasette
				MPS 801 Dot matrix printer
				MPS 802 Dot matrix printer
				MPS 803 Dot matrix printer
				DPS 1101 Daisey wheel printer
				C1520 Plotter/Printer
				C1702 Color monitor
				CM141 Color monitor

Power requirements
				120 Volts, 60 Hz













				Specifications subject to change without notice.




																			1
~

							  PARTS LIST C-64

   PLEASE NOTE: Commodore part numbers are priced 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 part will be stocked by Commodore and are
   indicated on the parts list by a "C".

		TOP CASE ASSY
			Top Case				C 326113-01
			Keyboard				C 326166-02
			LED Plate				C 326160-01
			Nameplate				C 326161-01
			Lamp Hold Set			C 903820-03
			LED Assembly			C 1001039-01

		BOTTOM CASE ASSY
			Bottom Case 			C 326114-01
            Foot, Self-Adhesive    C 950157-04
			PCB Shield Plate		C 326131-01
			PCB Insulation Sheet	C 326288-01

		ACCESSORIES
			Users Manual			C 326114-01
			Power Supply			C 950157-04
			RF Cable				C 326131-01
			Switch Box				C 326288-01
















																			2
~


[Figure: C-64 Block Diagram]











































																			3
~
														C64 CIRCUIT THEORY

  +-------------------------------------------------------------------------+
  | There are three versions of the C64. The C64 with five pine connector	|
  | video output (326106). The C64 with an eight pin connector video output |
  | (251138), and the C64B which has improved system clock circuit design	|
  | (251469). Most circuit theory explanations will be the same for all 	|
  | three versions. Refer to schematic 326106 unless noted otherwise.		|
  +-------------------------------------------------------------------------+

The Power Supply

The external power supply generates a regulated 5VDC and 9VAC. 5VDC is applied
to pins 5 and 1 of CN7 on the C64 pcb. Filtered by L5, C97, and C100 it is then
controlled by on/off switch S1. This 5VDC output supplies the microprocessor
logic.

9VAC is applied to pins 6 and 7 of CN7 on the C64 pcb. +12VDC, +5VDC CAN and
9VAC unregulated are outputs that are derived from this 9VAC supply. The 9VAC
supply is made available on pins 10 and 11 of the USER PORT CN2.


12VDC Generation

9VAC is added to 9VDC through CR6, and rectified by CR5. The unregulated DC
output is filtered by C88 and C89 then regulated at 12VDC by VR1. The regulated
output is filtered by C57 and C59. The 12VDC supplies the VIC and SID IC, and
the audio amplifiers.


+5VDC CAN Generation

9VAC is rectified by CR4. The unregulated DC output is filtered by C19, and C95
then regulated at 5VDC by VR2. The regulated output is filtered by C102 and
C103. The output called 5VDC CAN is separated and individually filtered into two
outputs called Vvid and Vc. Vvid is the 5VDC supply for video circuits, and Vc
is the 5VDC supply for the clock circuits.


9VDC Unregulated Generation

CR4 rectifies the 9VAC input. The output is 9VDC unregulated. This supply powers
the cassette motor transistor amplifier circuits, and the RF modulator on the
C64B version.


[Figure: Power Supply Circuits] 											4
~
														C64 CIRCUIT THEORY

[Figure: Reset Circuit schematic]


Reset Logic Circuits

U20 is a 556 timer configured as a one shot multivibrator. The output pulse
width is determined by the size of R34 and C24. Pulse width = 1.1 x R34 x
C24 = .5 seconds. The output on pin 9 is "high" active. The output of U8 is
"low" active. Reset initializes all the processor logic and causes the
processor to load the program counter register with the address of the
first instruction of the operating system program called the KERNAL. The
starting address is stored in locations $FFFC and $FFFD. The first
instruction is decode and executed giving KERNAL control of the computer
operations. The reset pulse occurs when turning the power on to the
computer.





























																			5
~
														C64 CIRCUIT THEORY

[Figure: Clock circuit schematic]


The C64 Clock Circuits.

Crystal Y1 develops a 14.31818MHz fundamental frequency clock signal. U31
is a Dual Voltage Controlled Oscillator. The output on pin 10 is a 14.31818
MHz clock signal called the color clock. R27 can be adjusted to obtain
exact output frequency. U30 is a frequency divider that outputs a 2MHz signal
on pin 6. U29 is a D flip flop which outputs a 1MHz signal on pin 9. U32 is
a Phase/Frequency Detector which compares the output of the U29 to the phase
0 clock, and outputs a dc voltage on pin 8 that is proportional to the phase
difference between the inputs. The second half of the Dual Voltage
Controller Oscillator U31 generates an 8.1818MHz clock signal called the
DOT Clock. The VIC IC divides the DOT clock by eight and outputs this as the
phase 0 clock on pin 17. The output of the Phase/Frequency Detector is
applied to the frequency control input pin 2 of U31. This causes tracking
of the dot clock and the color clock because one input, pin 4 of U32, is
the phase 0 clock which is derived from the dot clock, and the other pin 1
of U32, is derived from the color clock.


[Figure: Clock circuit (C64B) schematic]


The C64B Clock Circuits. Refer to schematic 251469

Crystal Y1 develops the fundamental 16Mhz clock signal. U31 is a Clock
Generator IC that outputs the 8.1818MHz DOT clock on pin 6, and the
14.31818 MHz color clock on pin 8.














																			6
~
														C64 CIRCUIT THEORY

[Figure: I/O, ROM and expansion port schematic]


I/O and ROM Address Decoding and Expansion Port.

I/O Address Decoding Logic

U17 is a Programmable logic array (PLA). The output F5 on pin 12 called I/O
goes "low" when any of the I/O devices controlled by U15 are selected. The
addresses are listed below for each device.

		VIC IC		 $D000 - $D02E
		SID IC		 $D400 - $D7FF
		Color Ram	 $D800 - $DBFF
		CIA 1		 $DC00 - $DC0F
		CIA 2		 $DD00 - $DD0F
		I/O 1		 $DE00 - $DEFF
		I/O 2		 $DF00 - $DFFF

ROM Address Decoding.

Basic ROM resides at locations $A000 - $BFFF. The output F1 pin 17 of the
PLA U17 goes "low" when the BASIC ROM is selected. The KERNAL ROM resides
at locations $E000 - $FFFF. The output F2 pin 16 of the PLA U17 goes "low"
when the KERNAL ROM is selected. The CHARACTER GENERATOR ROM resides at
locations $D000 - $DFFF. The output F3 pin 15 of the PLA U17 goes "low"
when the Character Generator ROM is selected.

The Expansion Port Connections.

The expansion port is an extension of the microprocessor address, data, and
control bus. ROML decodes addresses $8000 - $9FFF, and ROMH decodes
addresses $E000 - $FFFF. These are outputs from the PLA used to select the
catridge inserted in the expansion port. I/O 1 input from U15 decodes
addresses $DE00 - $DEFF. I/O 2 output from U15 decodes addresses $DF00 -
$DFFF.








																			7
~
														C64 CIRCUIT THEORY

[Figure: RAM control logic schematic]


RAM Control Logic.

U13 and U25 are multiplexers. The address output from the microprocessor
are passed to RAM via U13 and U25 when the output Address Enable Control
(AEC) from the VIC IC is "high". When AEC is "low" the VIC IC outputs
refresh addresses on pins 24 - 31. AEC goes "low" when the system clock,
phase 2, is "low". Since all I/O decoding occurs when phase 2 is "high",
refresh is transparent to the processor.

Eight 4164 DRAMS provide 64k bytes of memory. One 2114 RAM (U6) provides
512 bytes of memory allocated for screen color data storage.






























																			8
~
														C64 CIRCUIT THEORY

[Figure: 5 pin video and audio schematic]


5 Pin Video and Audio Output Circuits

Pin 15 of the VIC IC is the sync/luminance output. Pin 14 is the color
output. A composite video output is created by mixing sync/luminance and
color. The composite output is applied to the RF modulator, and also passed
to the monitor connector CN5 on pin 4. The color output is not made
available on the monitor connector CN5 as on the 8 pin version, and the RF
modulator mixes audio with the composite video producing the TV RF output,
unlike the 8 pin version RF modulator which creates the composite video
output.































																			9
~
														C64 CIRCUIT THEORY

[Figure: 8 pin video and audio schematic]



8 Pin Video and Audio Output Circuits. Refer to schematic 21469

U19 is the Video Interface Chip (VIC). Sync (horizontal and vertical), and
luminance (video) is output on pin 15. This signal is passed to pin 2 of
the RF modulator. Color is output on pin 14, and passed to pin 3 of the
modulator. Light pen inputs are sensed by the VIC IC on pin 9. U18 is the
Sound Interface Device (SID). The audio output is on pin 27, and audio
input is on pin 26. The RF modulator mixes sync/luminance, color, and audio
out, generating a TV composite signal on pin 5. The RF modulator also
passes the VIC outputs to the monitor connector CN5. Audio out on pin 27 is
amplified by Q2, and output on pin 3 of CN5. Audio in is applied to pin 5
of CN5, then to pin 26 of the SID IC. Inputs from paddles connected to on
of the control ports are monitored by the SID IC on pins 23 and 24.



























																		   10
~
														C64 CIRCUIT THEORY

[Figure: Cassette interface schematic]


The Cassette Interface Circuits.

U7 is a 6510 microprocessor. One of the features of the 6510 is a built in
parallel I/O port (P0-P5). P3 - P5 control most of the cassette interface
circuitry. P3 pin p6 of U7 outputs the write data signal to connector CN3
on pins E and 5. P4 is an input that senses the play switch depressed on the
cassette deck. P5 is on output that controls the cassette motor. When P5
goes "low", Q2 cuts off, CR2 regulates Vb of Q1 at 7.5 volts, this forward
biases Q1 and Q3, passing current through the cassette motor coil. U1 is a
Complex Interface Adapter (CIA). Parallel ports, serial outputs, and Timers
are standard features of the CIA. Read data enters on pins D, 4 of CN3. U1
accepts the read data signal on the FLAG input pin 24.





























																		   11
~
														C64 CIRCUIT THEORY

[Figure: Interface control schematic]


Keyboard, Joystick, and Paddle Interface Circuits.

Keyboard Interface

U1 is a Complex Interface Adapter (CIA). Both parallel ports are used to
decode the keyswitches on the keyboard. Parallel port A signals (PA0 - PA7)
are outputs. PArallel port B signals (PB0 - PB7) are inputs. A "0" bin is
shifted through the parallel port A, when a key is depressed on the
keyboard the "0" bit is returned on one of the parallel port B inputs. A
program in the KERNAL ROM generates the shifting "0" bit output on parallel
port A, and decodes the signals returning on the parallel port B inputs.
Depressing the restore key causes U20 to trigger. U9 pin 6 goes "low"
generating a Non- Maskable Interrupt (NMI) at the processor. This causes
the processor to execute a subroutine which initializes the I/O interfaces.
If the STOP key is depressed at the same time, BASIC flags are initialized.


[Figure: Keyboard matrix]


Joystick Interface

U1 also controls the joystick. Parallel port A accepts inputs from the B
joystick connected to control port 2. Parallel port B accepts inputs from
the A joystick connected to control port 1. When the joystick is moved up,
down, left, right, or the fire button is depressed, a ground potential is
applied to the appropriate input of U1.

Paddle Interface

A Variable resistor is connected to adjusting knob on the paddle. When the
knob is rotated, the resistance varies controlling the time constant of an
RC network. The Voltage developed across the capacitor is input to an A/D
converter internal to the SID chip U18. The digital output is stored in one
of the SID registers. The paddle position can be determined by the reading
the contents of the appropriate register. U28 is a 4066 CMOS switch. The
signals from the paddles are passed to the SID chip when the Enable inputs
(E0 - E3) of U28 are "high".

NOTE: U1 port assignments are incorrect on schematics. Refer to Keyboard
	  Matrix for correct assignments.
																		   12
~
														C64 CIRCUIT THEORY

[Figure: Serial interface schematic]


The Serial Interface and User Port Circuits

The Serial Interface.

U2 is a Complex Interface Adapter (CIA). Parallel port signals PA3-PA7
control the serial bus interface. PA3 is the Attention (ATN) output. This
signal is inverted by U8 before being transmitted to a device on the bus.
PA4 is the clock output. Data transmitted from the C64 to a device on the
bus is synchronized by this clock signal. U8 inverts the output PA4. PA5 is
the data output. U8 inverts this output also. Data transmitted from a device
on the bus to the C64 is synchronized by a clock generated by the
transmitting device. The Clock signal is input on PA6. Data transmitted
from a device on the bus to the C64 is input on PA7. When a device on the
bus wants to communicate with the C64, SQR IN goes "low" indicating service
is requested.


The User Port

Parallel port B of U2 (PB0 - PB7) is made available on the user port.
Parallel data transfers with external device are made very easily through
this parallel port. SP2 and SP1 are bi-directional serial ports. CNT1 and
CNT2 are bi-directional synchronizing clock signals for each serial bus.


















																		   13
~
						  64 TROUBLESHOOTING GUIDE
+--------------------------------------+------------------------------------+
|		   SYMPTOM					   |		  POSSIBLE SOLUTION 		|
+--------------------------------------+------------------------------------+
|Blank screen on power up.			   |Check External Power Supply 		|
|									   |	  U4 (KERNAL ROM), U17 (PLA)	|
|									   |	  U7 (6510 MPU), U3 (ROM)		|
|									   |	  U8 (7406 IC), U19 (VIC II)	|
|									   |	  U9-U12 (4164 RAM),			|
|									   |	  U21-U24 (4164 RAM)			|
|									   |	  BT2, CR4, VR1 				|
+--------------------------------------+------------------------------------+
|Out of memory error on power up.	   |Check U9-U12 (4164 RAM) 			|
|									   |	  U21-U24 (4164 RAM)			|
|									   |**** USE DIAGNOSTIC TEST - DISK 	|
+--------------------------------------+------------------------------------+
|No cursor displayed.				   |Check U1, U15, U7					|
|Intermittent blank screen. 		   |Check U2, U7						|
+--------------------------------------+------------------------------------+
|Powers up with graphics display and   |Check U14 (74LS258 IC)				|
|blinking cursor.					   |									|
+--------------------------------------+------------------------------------+
|Powers up with all the characters	   |Check U26 (74LS373 IC)				|
|displayed as blocks.				   |									|
+--------------------------------------+------------------------------------+
|Intermittent display.				   |Check C88 (Possible Bad Connection) |
+--------------------------------------+------------------------------------+
|Powers up with the 'PRESS PLAY ON     |Check U7 (6510 MPU)                 |
|TAPE' message and the display blanks. |R1 (Possible Bad Connection)        |
+--------------------------------------+------------------------------------+
|On power up the cursor lock up.	   |Check U7 (6510 MPU) 				|
|									   |	  U20 (556 IC)					|
+--------------------------------------+------------------------------------+
|When 'RETURN' is pressed after a run  |Check U3 (ROM)                      |
|command, the cursor goes back to	   |									|
|home position. 					   |									|
+--------------------------------------+------------------------------------+
|Poke command does not work.		   |Check U3 (ROM)						|
+--------------------------------------+------------------------------------+
|Joystick does not operate correctly.  |Check U1, U28 (6526 CIA)			|
+--------------------------------------+------------------------------------+
|Wrong frequency.					   |Check C70							|
+--------------------------------------+------------------------------------+
|No character lettering is displayed on|Check U3 (ROM)						|
|the screen.						   |	  U2 (CIA)						|
+--------------------------------------+------------------------------------+
																		   14
~
					64 TROUBLESHOOTING GUIDE (Continued)
+--------------------------------------+------------------------------------+
|		   SYMPTOM					   |		  POSSIBLE SOLUTION 		|
+--------------------------------------+------------------------------------+
|Graphic characters instead of letters |Check U19 (VIC II)					|
|displayed. 						   |									|
+--------------------------------------+------------------------------------+
|Power up message appears but no cursor|Check U1, U15, U7 and U4			|
+--------------------------------------+------------------------------------+
|Cursor jumps to back to home position.|Check U7 (6510 MPU) 				|
+--------------------------------------+------------------------------------+
|Abnormal colors appear in the letters.|Check U6 (2114 RAM) 				|
|									   |	  U16 (4066 IC) 				|
+--------------------------------------+------------------------------------+
|Different characters are displayed and|Check RAM                           |
|cursor is locked when turned on and   |									|
|off.								   |									|
+--------------------------------------+------------------------------------+
|System does not reset and the		   |Check U20 (556 IC)					|
|'RESTORE' key does not work.          |                                    |
+--------------------------------------+------------------------------------+
|White band scrolls down the screen.   |Check External Power Supply 		|
|(60 HZ HUM)						   |	  VR2 (5V Regulator)			|
+--------------------------------------+------------------------------------+
|Cursor disappears after the system    |Check U1 (6526 CIA) 				|
|warms up.							   |									|
+--------------------------------------+------------------------------------+
|SYNTAX ERROR displayed after system   |Check RAM, U3 (ROM) 				|
|warms up.							   |									|
+--------------------------------------+------------------------------------+
|Wavy screen after the system warms up.|Check External power supply 		|
|									   |	  U31 (74LS629 IC)				|
|									   |	  U30 (74LS193 IC)				|
+--------------------------------------+------------------------------------+
|The system resets when it warms up.   |Check U7 (6510 MPU) 				|
|									   |	  U3 (ROM)						|
+--------------------------------------+------------------------------------+
|Keyboard does not operate correctly   |Check U1 (6526 CIA) 				|
|when the system warms up.			   |U3 (ROM)							|
+--------------------------------------+------------------------------------+
|Black band scrolls through screen	   |Check External Power Supply 		|
|when the system warms up.			   |	  C90, C88, CR4 				|
|									   |	  VR2 (5V Regulator)			|
+--------------------------------------+------------------------------------+
|Cassette motor keeps running.		   |Check U7 (6510 MPU) 				|
+--------------------------------------+------------------------------------+
																		   15
~
					64 TROUBLESHOOTING GUIDE (Continued)
+--------------------------------------+------------------------------------+
|		   SYMPTOM					   |		  POSSIBLE SOLUTION 		|
+--------------------------------------+------------------------------------+
|Cassette motor keeps running even	   |Check Cassette Port for Shorts		|
|after a program is done loading. The  |	  R4 (Possibly Open)			|
|TIP 29 transistor gets extremely hot  |									|
|and the fuse may possibly blow.	   |									|
+--------------------------------------+------------------------------------+
|The cursor disappears when the        |Check U7 (6510 MPU)                 |
|cassette is plugged in.			   |									|
+--------------------------------------+------------------------------------+
|Cassette runs extremely slow. The	   |Check U7 (6510 MPU) 				|
|program seems to load but will not run|									|
+--------------------------------------+------------------------------------+
|When loading from cassette, the	   |Check U20 (556 IC)					|
|'SYNTAX ERROR' message is displayed.  |                                    |
+--------------------------------------+------------------------------------+
|DEVICE NOT PRESENT ERROR is displayed |Check U1 (6526 CIA) 				|
|when disk is used. 				   |	  U7 (6510 MPU) 				|
|									   |	  R28, R29, R30 				|
+--------------------------------------+------------------------------------+
|Disk drives continue to search when   |Check U2 (6526 CIA) 				|
|trying to load.					   |									|
+--------------------------------------+------------------------------------+
|When loading from disk and any key of |Check U20 (556 IC)					|
|the 4th row of the keyboard is 	   |	  R35 (Possible Bad Connection) |
|pressed, the cursor goes to home	   |									|
|position.							   |									|
+--------------------------------------+------------------------------------+
|When loading from disk, a 'FILE NOT   |Check U4 (ROM)                      |
|FOUND' message is displayed.          |      U2 (6526 CIA)                 |
+--------------------------------------+------------------------------------+
|OUT OF MEMORY is displayed when disk  |Check U20 (556 IC)					|
|is used.							   |									|
+--------------------------------------+------------------------------------+










																		   16
~
                             C64 BOARD IDENTIFICATION


			To date there are 4 version of 64 PCB assemblies in use.


VERSION 		IDENTIFYING FACTORS 			PCB ASSY #		SCHEMATIC #

Original		5 pin board 					326298-01		326106
				(CN5-Video port has 5 pins)

A (CR)			8 pin board 					250407-04		251138
				(CN5-Video port has 8 pins)

B				8 pin board 					250425			251469
				(Reduced oscillator circuit)

B-2 			8 pin board 					250441-01*		251469


 - These boards are interchangeable with casework, keyboard, etc.; however,
   care must be taken to provide the customer with a unit that is
   compatible with their monitor and cable.

 - When component level repairs are necessary, be certain to acquire the
   appropriate part for the board you are repairing. Most modulators are
   different, as are many of the components.


* The 4th version of 64 board was recently developed and only a few may be
in the field. It is termed the 64B-2. All circuits remain the same as the
64B (Schematic 251469) with a few component location changes:

	1)	Resistors 28, 29, 30, 36, 48 were reduced to Resistor Pack RP5.

    2)  Diodes CR100-105 are no longer piggybacked. Their new locations are
		CR9, 12-16.









																		   17
~
						  BOARD LAYOUT #326298-01


[Figure: Board Layout #326298-01]










































																		   18
~
					 PARTS LIST - PCB ASSEMBLY #326298
				C - Indicates Commodore Stocked Part Numbers

  INTEGRATED CIRCUITS
U1,U2	6526 CIA					C 906108-01
U3		2364 Basic ROM				C 901226-01
U4		2364 Kernal ROM 			C 901227-03
U5		2364 Char ROM				C 901225-01
U6		2114L-30 RAM				  901453-01
U7		6510 uProcessor 			C 906107-01
U8		7406						  901522-06
U9-U12	4164 (200 nS)				  901505-01
U13 	74LS257 					  901521-57
U14 	74LS258 					  901521-58
U15 	74LS139 					  901521-18
U16 	4066						  901502-01
U17 	82S100 PLA					C 906114-01
U18 	6581 SID					C 906112-01
U19 	6567 VIC II 				C 906109-04
U20 	LM556						  901523-03
U21-U24 4161 (200 nS)				  901505-01
U25 	74LS257 					  901521-57
U26 	74LS373 					  901521-29
U27 	74LS08						  901521-03
U28 	4066						  901502-01
U29 	74LS74						  901521-06
U30 	74LS193 					  901521-26
U31 	74LS629 					  901521-68
U32 	MC4044						  906128-01
  TRANSISTORS
Q1		2N4401						  902652-01
Q2		2N3904						  902658-01
Q3		TIP29 B 					  902653-01
Q4-8	2N2222						  902686-01
  DIODES
CR1 	2.7V Zener IN4371
CR2 	7.5V Zener IN755
CR3 	IN914
CR4 	Bridge, Varo VMO8			  906129-01
CR5,6	Rectifier IN4001
  RESISTORS - All values are in ohms- 1/4W,
			  5%, unless noted otherwise.
R1	3.3K		R7	10K
R2	1.5K		R8	390
R3	10K 		R9	75
R4	1K			R10 120
R5	560 		R11 120
~
R6	1K			R13 1K
  RESISTORS (continued)
R14 100 		R30 1K
R16 1K			R31 180
R17 1.2K		R33 47K
R19 15K 		R34 47K
R20 6.8K		R35 470K
R21 4.7K		R37 2.7K
R22 1.5K		R38 1K
R23 1K			R39 390
R24 3.3K		R41 1M
R25 Pot 1K		R43 3.3K
R26 75			R44 3.3K
R27 Pot 2K		R45 3.3K
R28 1K			R46 2K
R29 1K			R51 1.5K
NOTE: The input video line requires a 470 ohm,
	  1/4 watt, resistor soldered to ground.

  RESISTOR PACKS
RP1,2	33, 8 Pin (Bourne No. 430BR-102-330)
RP3 	33K, 8 Pin (Bourne No. 430BR-101-332)
RP4 	3.3K, 10 Pin
  CAPACITORS
C1-3		Ceramic 		 .1 uF, 50V
C4-7		Ceramic 		.47 uF, 50V, 20%
C8			Electrolytic	 10 uF, 25V, +50%, -10%
C9			Ceramic 		.47 uF, 50V, 20%
C10-11		Ceramic 		470 pF, 50V
C12-15		Electrolytic	 10 uF, 25V, +50%, -10%
C16 		Ceramic 		 .1 uF, 50V
C17         Electrolytic     10 uF, 25V, +50%, -10%
C18 		Ceramic 		 .1 uF, 50V
C19         Electrolytic   2200 uF, 16V
C20,21		Film			.22 uF, 100V, 20%
C22 		Ceramic 		 .1 uF, 50V
C23 		Ceramic 		360 pF, 50V
C24 		Electrolytic	 10 uF, 25V, +50%, -10%
C25-28		Ceramic 		.22 uF, 50V
C29 		Ceramic 		.47 uF, 50V, 20%
C30,31,32	Ceramic 		 .1 uF, 50V
C33 		Ceramic 		.47 uF, 50V, 20%
C34         Electrolytic     10 uF, 25V, +50%, -10%
C35 		Ceramic 		 .1 uF, 50V
C36 		Ceramic 		 20 pF, 50V
C37 		Ceramic 	   1000 pF, 50V
																		   19
~
			   PARTS LIST - PCB ASSEMBLY #326298 (Continued)
				C - Indicates Commodore Stocked Part Numbers

  CAPACITORS (Continued)
C38 		Ceramic 		 51 uF, 50V
C39 		Ceramic 		 .1 uF, 50V
C40-43		Ceramic 		.22 uF, 25V, +50%, -10%
C44 		Ceramic 		.47 uF, 50V, 20%
C45,46,47	Ceramic 		 .1 uF, 50V
C48 		Ceramic 	   1800 uF, 50V
C49 		Ceramic 		470 pF, 50V
C50 		Ceramic 		.22 uF, 50V
C51 		Ceramic 		.47 uF, 50V, 20%
C52,53		Ceramic 		470 pF, 50V
C54 		Ceramic 		.22 uF, 50V
C55 		Ceramic 		 .1 uF, 50V
C56 		Ceramic 		 .1 uF, 50V
C57 		Electrolytic	 10 uF, 25V, +50%, -10%
C58 		Ceramic 		 .1 uF, 50V
C59 		Ceramic 		.22 uF, 50V
C60,61		Ceramic 		.47 uF, 50V, 20%
C62 		Electrolytic	 10 uF, 25V, +50%, -10%
C63 		Ceramic 		.47 uF, 50V, 20%
C64,65		Electrolytic	 10 uF, 25V, +50%, -10%
C66,67		Ceramic 		.47 uF, 50V, 20%
C68 		Ceramic 		 .1 uF, 50V
C69
C70 		Mica			 10 pF, 500V, 5%
C71 		Ceramic 		 .1 uF, 50V
C72 		Ceramic 		220 pF, 50V
C73 		Ceramic 		150 pF, 50V
C74 		Ceramic 		 .1 uF, 50V
C77 		Ceramic 		 .1 uF, 50V
C78 		Ceramic 		220 pF, 50V
C79 		Ceramic 		510 pF, 50V
C80 		Ceramic 		 51 pF, 50V
C81 		Ceramic 		 20 pF, 50V
C82 		Ceramic 		 .1 uF, 50V
C83 		Mica			.33 pF, 500V, 5%
C84 		Ceramic 		 .1 uF, 50V
C85 		Ceramic 		.47 uF, 50V, 20%
C86 		Mica			 39 pF, 500V, 5%
C87 		Ceramic 		 .1 uF, 50V
C88 		Electrolytic	470 uF, 50V
C89 		Ceramic 		 .1 uF, 50V
C90 		Electrolytic	470 uF, 50V
C91 		Electrolytic	100 uF, 16V
~
C92 		Ceramic 		.22 uF, 50V
C93 		Ceramic 	   1800 uF, 50V

  CAPACITORS (Continued)
C94 		Electrolytic	 10 uF, 25V, +50%, -10%
C95,96		Ceramic 		 .1 uF, 50V
C97 		Ceramic 		.22 uF, 25V
C98,99		Ceramic 		 .1 uF, 50V
C100		Ceramic 		.22 uF, 25V
C101		Ceramic 		 .1 uF, 50V
C102		Electrolytic	 10 uF, 25V, +50%, -10%
C103		Ceramic 		 .1 uF, 50V
C105		Ceramic 		 .1 uF, 50V

  CONNECTORS
CN1 	Header Assy 20 Pin			  903331-20
CN4 	6 Pin Din					C 903361-01
CN5 	5 Pin Din					C 903362-01
CN6 	44 Pin Card Edge			C 906100-02
CN7 	7 Pin Din					C 906130-01
CN8,9	Plug Assy, 8 Pin Rt. Angle	C 906126-01
CN10	Header Assy, 3 Pin

  MISCELLANEOUS
L1,2	Coil Inductor 2.2 uH		  901151-17
L3		Coil Inductor 3.0 uH		  901151-21
L4		Filter Line Assy			C 906127-01
L5		Coil Inductor 1.2 uH		  901152-01
Y1		Crystal 14.31818 MHz		C 900558-01
SW1 	Rocker Switch DPDT			C 904500-01
VR1 	Voltage Regulator MC7812CT
VR2 	Voltage Regulator MC7805CT
M1		Modulator					C 326130-01
F1		Fuse, Normal Blo, 250V, 1.5A
FB1-23	Ferrite Bread				  903025-01
		Connector Panel
			(ON, OFF, Joystick) 	  326299-01
		Catridge Guide				  326116-01
		Shield Box					C 326265-01
		Shield Cap					C 326267-01






																		   20
~
					   SCHEMATIC #326106 SHEET 1 OF 2


[Figure: Schematic #326106 sheet 1 of 2]










































																		   21
~
					   SCHEMATIC #326106 SHEET 2 OF 2


[Figure: Schematic #326106 sheet 2 of 2]










































																		   22
~
						  BOARD LAYOUT #250407-04


[Figure: Board Layout #250407-04]










































																		   23
~
					PARTS LIST - PCB ASSEMBLY #250407-04
				C - Indicates Commodore Stocked Part Numbers

  INTEGRATED CIRCUITS
U1,U2	6526 CIA					C 906108-01
U3		2364 Basic ROM				C 901226-01
U4		2364 Kernal ROM 			C 901227-03
U5		2364 Char ROM				C 901225-01
U6		2114L-30 RAM				  901453-01
U7		6510 uProcessor 			C 906107-01
U8		7406						  901522-06 sub:
		7416						  901522-14
U9-U12	4164 (200 nS)				  901505-01
U13 	74LS257 					  901521-57
U14 	74LS258 					  901521-58
U15 	74LS139 					  901521-18
U16 	4066						  901502-01
U17 	82S100 PLA					C 906114-01
U18 	6581 SID					C 906112-01
U19 	6567 VIC II 				C 906109-04
U20 	LM556						  901523-03
U21-U24 4161 (200 nS)				  901505-01
U25 	74LS257 					  901521-57
U26 	74LS373 					  901521-29
U27 	74LS08						  901521-03
U28 	4066						  901502-01
U29 	74LS74						  901521-06
U30 	74LS193 					  901521-26
U31 	74LS629 					  901521-68
U32 	MC4044						  906128-01
  TRANSISTORS
Q1,2	2SC1815 					C 902693-01
Q3		TIP29 A 					  902653-01
Q7,8	2SC1815 					C 902693-01
  DIODES
CR1 	2.7V Zener IN4371			  906103-02
CR2 	7.5V Zener IN755			  900941-01
CR4 	Bridge S2VB10				C 251026-01
			   DBA20B				C 251026-02
			   DBA20C				C 251026-03
CR5,6	Rectifier IN4001			  900750-01
  RESISTORS - All values are in ohms- 1/4W,
			  5%, unless noted otherwise.
R1	3.3K		R6	 1K
R2	1.5K		R7	 10K
R3	10K 		R16  1K
R4	1K			R17  2.7K
~
R5	560 		R19  15K
  RESISTORS (continued)
R26 75			R39  390
R27 Pot 2K		R41  1M
R28 1K			R42  82
R29 1K			R43  3.3K
R30 1K			R44  3.3K
R31 180 		R45  3.3K
R33 47K 		R50  1M
R34 47K 		R51  1.5K
R35 470K		R52  300
R36 1K			R53  390
R37 2.7K		R100 1K
R38 1K			R101 22K
  RESISTOR PACKS
RP1,2	33, 8 Pin (Bourne No. 430BR-102-330)
RP3 	33K, 8 Pin (Bourne No. 430BR-101-332)
RP4 	3.3K, 10 Pin
  CAPACITORS
C1-7		Ceramic 		 .1 uF, 25V
C8			Electrolytic	 10 uF, 25V, +50%, -10%
C9			Ceramic 		 .1 uF, 25V
C10,11		Ceramic 		470 pF, 50V
C12 		Ceramic 		 .1 uF, 25V
C13,14,15	Electrolytic	 10 uF, 25V, +50%, -10%
C16 		Ceramic 		 .1 uF, 25V
C17         Electrolytic     10 uF, 25V, +50%, -10%
C18 		Ceramic 		 .1 uF, 25V
C19         Electrolytic   2200 uF, 16V
C20,21		Film			.22 uF, 100V, 20%
C22 		Ceramic 		 .1 uF, 25V
C23 		Ceramic 		360 pF, 50V
C24 		Electrolytic	 10 uF, 25V, +50%, -10%
C25-33		Ceramic 		 .1 uF, 25V
C34         Electrolytic     10 uF, 25V, +50%, -10%
C35 		Ceramic 		 .1 uF, 50V
C36 		Ceramic 		 20 pF, 50V, 5% SL
C37 		Ceramic 	   1000 pF, 50V, 10% B
C38 		Ceramic 		 51 uF, 50V, 5% SL
C39-47		Ceramic 		 .1 uF, 25V
C48 		Ceramic 	   1800 pF, 50V, 10% B
C49-54		Ceramic 		 .1 uF, 25V
C55 		Ceramic 		 .1 uF, 50V
C56 		Ceramic 		 .1 uF, 25V
C57 		Electrolytic	 10 uF, 25V, +50%, -10%
C58 		Ceramic 		 .1 uF, 50V
																		   24
~
			  PARTS LIST - PCB ASSEMBLY #250407-04 (Continued)
				C - Indicates Commodore Stocked Part Numbers

  CAPACITORS (Continued)
C59,60		Ceramic 		 .1 uF, 25V
C62,65		Electrolytic	 10 uF, 25V, +50%, -10%
C66,67,68	Ceramic 		 .1 uF, 25V
C70 		Film			 16 pF, 5%
C74,82		Ceramic 		 .1 uF, 25V
C83 		Ceramic 		 82 pF, 5%
C84 		Ceramic 		 .1 uF, 25V
C85 		Ceramic 		.47 uF, 50V, 10%
C88 		Electrolytic   1000 uF, 25V
C89 		Ceramic 		 .1 uF, 25V
C90 		Electrolytic	470 uF, 50V
C91 		Electrolytic	100 uF, 16V, +50%, -10%
C92 		Ceramic 		 .1 uF, 25V
C93 		Ceramic 	   1800 pF, 50V, 10% B
C94 		Electrolytic	 10 uF, 25V, +50%, -10%
C95,96		Ceramic 		 .1 uF, 25V
C97 		Ceramic 		.22 uF, 25V
C98,99		Ceramic 		 .1 uF, 25V, +80%, -20%
C100		Ceramic 		.22 uF, 25V
C101		Ceramic 		 .1 uF, 50V, +80%, -20%
C102		Electrolytic	 10 uF, 25V, +50%, -10%
C103		Ceramic 		 .1 uF, 25V
C104
C105		Ceramic 		 .1 uF, 25V
C108		Electrolytic	 10 uF, 25V, +50%, -10%
C200		Ceramic 		 .1 uF, 25V

  CONNECTORS
CN1 	Header Assy 20 Pin			  903331-20
CN4 	6 Pin Din					C 903361-01
CN5 	8 Pin Din					C 325573-01
CN6 	44 Pin Card Edge			C 906100-02
CN7 	7 Pin Din					C 251116-01
CN8,9	Plug Assy, 9 Pin MINID		C 906126-01
CN10	Header Assy, 3 Pin			  903332-03

  MISCELLANEOUS
L2		Coil Inductor 2.2 uH		  901151-17
L4		Coil Inductor 1.2 uH		  325570-01
L5		Choke Coil					C 325559-02
Y1		Crystal 14.31818 MHz		C 900558-01
SW1 	Rocker Switch DPDT			C 904500-01
VR1 	Voltage Regulator MC7812CT	  901527-01
~
VR2 	Voltage Regulator MC7805CT	  901527-02
M1		Modulator					C 251080-01
F1		Fuse, Normal Blo, 250V, 1.5A
FB1-23	Ferrite Bread				  903025-01
		Connector Panel
			(ON, OFF, Joystick) 	  251095-01
		Catridge Guide				  326116-01
		Shield Box					C 251023-01
		Shield Cap					C 251024-01





































																		   25
~
						MODULATOR SCHEMATIC #251025

[Figure: Modulator schematic #251025]





					   SCHEMATIC #251138 SHEET 1 OF 2


[Figure: Schematic #251138 sheet 1 of 2]


































																		   26
~
					   SCHEMATIC #251138 SHEET 2 OF 2


[Figure: Schematic #251138 sheet 2 of 2]










































																		   27
~
						  BOARD LAYOUT #250425-01


[Figure: Board Layout #250425-01]










































																		   28
~
					PARTS LIST - PCB ASSEMBLY #250425-01
				C - Indicates Commodore Stocked Part Numbers

  INTEGRATED CIRCUITS
U1,U2	6526 CIA					C 906108-01
U3		2364 Basic ROM				C 901226-01
U4		2364 Kernal ROM 			C 901227-03
U5		2364 Char ROM				C 901225-01
U6		2114L-30 RAM				  901453-01
U7		6510 uProcessor 			C 906107-01
U8		7406						  901522-06 sub:
		7416						  901522-14
U9-U12	4164 (200 nS)				  901505-01
U13 	74LS257 					  901521-57
U14 	74LS258 					  901521-58
U15 	74LS139 					  901521-18
U16 	4066						  901502-01
U17 	82S100 PLA					C 906114-01
U18 	6581 SID					C 906112-01
U19 	6567 VIC II 				C 906109-04
U20 	LM556						  901523-03
U21-U24 4161 (200 nS)				  901505-01
U25 	74LS257 					  901521-57
U26 	74LS373 					  901521-29
U27 	74LS08						  901521-03
U28 	4066						  901502-01
U31 	7701/8701					C 251527-01
  TRANSISTORS
Q1		TIP29 A 					  902653-01
Q2-4	2SC1815 					C 902693-01
  DIODES
CR1 	2.7V Zener IN4371			  906103-02
CR2 	6.8V Zener IN755
CR4 	Bridge S2VB10				C 251026-01 sub:
			   DBA20B				C 251026-02 sub:
			   DBA20C				C 251026-03
CR5,6	Rectifier IN4001			  900750-01
CR9,			  IN4148 sub:
CR12-16 		  IN914
CR100-105
  RESISTORS - All values are in ohms- 1/4W,
			  5%, unless noted otherwise.
R1	3.3K		R26  3.3K
R2	1.5K		R31 180
R3	10K 		R33 47K
R4	1K			R34 47K
R5	560 		R35 470K
~
R6	 1K 		R37 2.7K
R7	 10K		R38 1K
  RESISTORS (continued)
R39  390		R50  1M
R41  1M 		R51  1.5K
R42  82 		R60  100
R43  3.3K		R100 1K
R44  3.3K		R101 22K
R45  3.3K
  RESISTOR PACKS
RP1,2	33, 8 Pin (Bourne No. 430BR-102-330)
RP3 	33K, 8 Pin (Bourne No. 430BR-101-332)
RP4 	3.3K, 10 Pin
RP5 	1K, 6 Pin
  CAPACITORS
C1-7		Ceramic 		 .1 uF, 25V
C9			Ceramic 		 .1 uF, 25V
C10,11		Ceramic 		470 pF, 50V, 10%
C12 		Ceramic 		 .1 uF, 25V
C13 		Electrolytic	 10 uF, 25V, +50%, -10%
C15 		Tantalum		4.7 uF, 16V, 20%
C19         Electrolytic   2200 uF, 16V
C20 		Film			.22 uF, 100V, 20%
C22 		Ceramic 		 .1 uF, 25V
C23 		Ceramic 		360 pF, 50V, 10% sub: 390 pF
C24 		Electrolytic	 22 uF, 25V, +50%, -10%
C31,33,34	Ceramic 		 .1 uF, 25V
C37 		Ceramic 	   1000 pF, 50V, 10% B
C38 		Ceramic 		 51 pF, 50V, 5% SL
C39-46		Ceramic 		 .1 uF, 25V
C48 		Ceramic 	   1800 pF, 50V, 10% B
C50,51,53	Ceramic 		 .1 uF, 25V
C59 		Ceramic 		 .1 uF, 25V
C88 		Electrolytic   1000 uF, 25V
C90 		Electrolytic	470 uF, 50V
C91 		Electrolytic	100 uF, 16V, +50%, -10%
C93 		Ceramic 	   1800 pF, 50V, 10% B
C101		Ceramic 		 .1 uF, 50V, +80%, -20%
C102		Electrolytic	 10 uF, 25V, +50%, -10%
C150-152	Ceramic 		470 pF, 50V, 10%
C153		Ceramic 		 68 pF, 50V, 5%
C154		Ceramic 		470 pF, 50V, 10%
C200		Ceramic 		 .1 uF, 25V
C204		Ceramic 		150 pF, 50V, 10%
C205		Ceramic 		220 pF, 50V, 5%
CT1 		Trimmer 		 40 pF
																		   29
~
			  PARTS LIST - PCB ASSEMBLY #250407-04 (Continued)
				C - Indicates Commodore Stocked Part Numbers

  CONNECTORS
CN1 	Header Assy 20 Pin			  903331-20
CN4 	6 Pin Din					C 903361-01
CN5 	8 Pin Din					C 325573-01
CN6 	44 Pin Card Edge			C 906100-02
CN7 	7 Pin Din					C 251116-01
CN8,9	Plug Assy, 9 Pin MINID		C 251057-01
CN10	Header Assy, 3 Pin			  903332-03

  MISCELLANEOUS
L2		Coil Inductor 2.2 uH		  901151-17
L4		Line Filter Assy			C 251701-01
L5		Coil Inductor 1.2 uH		  901152-01
Y1		Crystal 14.31818 MHz		C 251707-01
SW1 	Rocker Switch DPDT			C 904500-01
VR1 	Voltage Regulator MC7812CT	  901527-01
VR2 	Voltage Regulator MC7805CT	  901527-02
M1		Modulator					C 251696-01
		Connector Panel
			(ON, OFF, Joystick) 	  251095-01
		Catridge Guide				  326116-01
F1		Fuse, Normal Blo, 250V, 1.5A





















																		   30
~
						MODULATOR SCHEMATIC #251696

[Figure: Modulator schematic #251696]








					   SCHEMATIC #251469 SHEET 1 OF 2


[Figure: Schematic #251469 sheet 1 of 2]































																		   31
~
					   SCHEMATIC #251469 SHEET 2 OF 2


[Figure: Schematic #251469 sheet 2 of 2]










































																		   32
~
							 U1, U2 - 906108-01
						   6526 COMPLEX INTERFACE
							   ADAPTER (CIA)

		  PIN				1		VSS 	Ground connection
	   ASSIGNMENT			2-9 	PA0-PA7 Parallel port a signals.
	  +----------+							Bidirectional parallel port.
	  | 		 |			10-17	PB0-PB7 Parallel port b signals.
  GND-+ 1	   40+-CNT						Bidirectional parallel port.
  PA0-+ 2	   39+-SP		18		PC		Handshake output. A low pulse is
  PA1-+ 3	   38+-RS0						generated after a read or write
  PA2-+ 4	   37+-RS1						on port b.
  PA3-+ 5	   36+-RS2		19		TOD 	Time od day clock input.
  PA4-+ 6	   35+-RS3						Programmable 50hz or 60hz.
  PA5-+ 7	   34+-_RES 	20		VCC 	5VDC input.
  PA6-+ 8	   33+-DB0		21		IRQ 	Interrupt output to microprocessor
  PA7-+ 9	   32+-DB1						input IRQ.
  PA0-+10	   31+-DB2		22		R/W 	READ/WRITE input from
  PB1-+11	   20+-DB3						microprocessor's R/W output.
  PB2-+12	   29+-DB4		23		CS		Chip select input. A low pulse
  PB3-+13	   28+-DB5						will activate CIA.
  PB4-+14	   27+-DB6		24		FLAG	Negative edge sensitive interrupt
  PB5-+15	   26+-DB7						input. Can be used as a handshake
  PB6-+16	   25+-O2						line for either parallel port.
  PB7-+17	   24+-_FLAG	25		O2		O2 clock input. Connected to
  PPC-+18	   23+-_CS						processor common O2 clock.
  TOD-+19	   22+-R/_W 	26-33	DB0-DB7 Bidirectional data bus. Connects
  VCC-+20	   21+-_IRQ 					to processor data bus.
	  | 		 |			34		RES 	Low active reset input.
	  +----------+							Initializes CIA.
							35-38	RS0-RS3 Register select inputs. Used to
											select all internal registers
											for communications with the
											parallel ports, time of day
											clock and serial port (SP).
							39		SP		Serial Port bidirectional
											connection. An internal shift
                                            register converts
											microprocessor parallel data
											into serial data, and vice
											versa.
							40		CNT 	Count input. Internal timers
											can count pulses applied to
											this input. cAn be used for
											frequency dependant operations.


~
							  U18 - 906112-01
							6581 SOUND INTERFACE
								DEVICE (SID)



		  PIN				1,2,	CAP1A,1B
	   ASSIGNMENT			3,4 	2A,2B	Capacitor filter connections
	  +----------+			5		RES 	Reset input. A low pulse
	  | 		 |							initializes the SID.
  CAP-+1A	   28+-12V		6		O2		Processor phase 2 clock input.
  CAP-+1B	   27+-A.OUT	7		R/W 	Processor read/write input.
  CAP-+2A	   26+-EXT IN	8		CS		Chip select input.
  CAP-+2B	   25+-5V		9-13	A0-A4	Address lines from processor.
 _RES-+ 5	   24+-POT X	14		GND 	Dc ground connection.
   O2-+ 6	   23+-POT Y	15-22	D0-D7	Data Bus connections.
 R/_W-+ 7	   22+-D7		23		POT Y	Input to a A/D converter used to
  _CS-+ 8	   21+-D6						detect the value of a variable
   A0-+ 9	   20+-D5						resistor. Commonly connected to
   A1-+10	   19+-D4						game paddles.
   A2-+11	   18+-D3		24		POT X	Same as POT Y.
   A3-+12	   17+-D2		25		VCC 	5VDC.
   A4-+13	   16+-D1		26		EXT IN	External audio input.
  GND-+14	   15+-D0		27		A.OUT	Audio output. Should be AC coupled
	  | 		 |							to audio amp.
	  +----------+			28		Vdd 	12VDC.





















~
							   U7 - 906107-01
							6510 MICROPROCESSOR

		  PIN				1		O1		Phase 1 clock input. This clock
	   ASSIGNMENT							input is used to develop the
	  +----------+							internal overlapping phase 2
	  | 		 |							clock. 1MegHz or 2 MegHz
   O1-+ 1	   40+-_RES 					speeds.
  RDY-+ 2	   39+-O2		2		RDY 	Single step operation input. A
 _IRQ-+ 3	   38+-R/_W 					low applied will cause the
 _NMI-+ 4	   37+-DB0						processor to halt. The current
  AEC-+ 5	   36+-DB1						address line being fetched will
  VCC-+ 6	   35+-DB2						be on the address bus. Can also
   A0-+ 7	   34+-DB3						be used to interface slower
   A1-+ 8	   33+-DB4						devices to the microprocessor.
   A2-+ 9	   32+-DB5		3		IRQ 	Interrupt request input. When a
   A3-+10	   31+-DB6						low pulse is applied a jump to
   A4-+11	   20+-DB7						a location specified by the
   A5-+12	   29+-P0						contents of FFFE and FFFF will
   A6-+13	   28+-P1						occur to service the interrupt,
   A7-+14	   27+-P2						if the interrupt mask flag is
   A8-+15	   26+-P3						not set. This is a maskable
   A9-+16	   25+-P4						interrupt.
  A10-+17	   24+-P5		4		NMI 	Non-maskable interrupt input. A
  A11-+18	   23+-A15						low transition will cause a
  A12-+19	   22+-A14						jump to a location specified by
  A13-+20	   21+-GND						FFFA and FFFB to a subroutine
	  | 		 |							which will service the
	  +----------+							interrupt.
							5		AEC 	Address enable control input. A
											low applied to will cause the
											address bus to enter hi
											impedance state, so other
											devices can control the address
											bus.
							6		VCC 	5VDC input.
							7-20	A0-A15	Address bus outputs.
							22,23			Unidirectional bus used to
											address memory and I/O devices.
											The address bus can be disabled
											by controlling the AEC input.
							21		GND 	Dc ground connection.
							24-29	P0-P5	I/O bidirectional port. This
											port can be controlled via
											memory locations 0000 and 0001.
											0001 = Output register
											0000 = Data direction register
~
                            30-37   DB0-DB7 Bidirectional data bus. This is
                                            the bus that passes the data
											to or from any I/O device or
											memory.
							38		R/W 	Read/Write output. The
											processor generates a low level
											when writing, and a high level
											when reading. This signal is
											usually decoded for read or
											write operations to memory or
											I/O.
							39		O2		Phase 2 output. The processor
											generates this clock signal
											from the phase 1 clock applied.
											The two clock signals are 180
											degrees out of the phase. The
											phase 2 clock is used in
											decoding I/O and memory on the
											positive half cycle.
							40		RES 	Reset input interrupt. A low
											pulse causes a jump to a
											subroutine specified by FFFC
											and FFFD, which will initialize
											the all processor controlled
											devices. This occurs during a
											power up sequence.
			-----------------------------------------
		  PIN
	   ASSIGNMENT
	  +----------+
	  | 		 |
 PE+ -+ 1	   28+-VCC			  U17 - 906114-01
   I7-+ 2	   27+-I8				PROGRAMMABLE
   I6-+ 3	   26+-I9			 LOGIC ARRAY (PLA)
   I5-+ 4	   25+-I10
   I4-+ 5	   24+-I11
   I3-+ 6	   23+-I12
   I2-+ 7	   22+-I13
   I1-+ 8	   21+-I14
   I0-+ 9	   20+-I15
   F7-+10	   19+-CE
   F6-+11	   18+-F0
   F5-+12	   17+-F1
   F4-+13	   16+-F2
  GND-+14	   15+-F3
	  | 		 |
	  +----------+
~
							  U19 - 906109-01
							6567 VIDEO INTERFACE
							  CHIP II (VIC II)

                                    PIN
                                 ASSIGNMENT
                                +----------+
                                |          |
                            DB6-+ 1      40+-VCC
                            DB5-+ 2      39+-DB7
                            DB4-+ 3      38+-DB8
                            DB3-+ 4      37+-DB9
                            DB2-+ 5      36+-DB10
                            DB1-+ 6      35+-DB11
                            DB0-+ 7      34+-A10
                           _IRQ-+ 8      33+-A9
                             LP-+ 9      32+-A8
                            _CS-+10      31+-A7
                           R/_W-+11      20+-A6 ("1")
                             BA-+12      29+-A5
                            VDD-+13      28+-A4
                          COLOR-+14      27+-A3
                       SYNC/LUM-+15      26+-A2
                            AEC-+16      25+-A1
                            PH0-+17      24+-A0
                           _RAS-+18      23+-A11
                           _CAS-+19      22+-PHIN
                            VSS-+20      21+-PHCL
                                |          |
                                +----------+
                                MULTIPLEXED
                          ADDRESSES IN PARENTHESES


    1-7/39  DB0-DB7 Processor data bus connections. Bidirectional data.
    8       IRQ     Interrupt output. Generates a interrupt signal to the
                    processor indicating service is needed. The light pen
                    input can be acknowledged thru use of this interrupt.
    10      CS      Chip select input. A low signal selects the VIC II.
    11      R/W     Processor read/write connection.
    12      BA      Bus available output. A low pulse output indicates the
                    VIC II chip wants control of the processor network to
                    process faster video operations that the system clock
                    can handle.
    13      VDD     12VDC input.
    14      COLOR   Output contains chrominance, color reference burst, and
                    color of display data.
~
    15      SYNC/   Output containing video, horizontal and vertical sync,
            LUM     and luminance information.
    16      AEC     Address enable output. This is usually connected to the
                    processor AEC input controlling the address bus.
                    AEC = 0 processor address bus disabled, refresh ram.
                    AEC = 1 processor address bus enabled. This allows
                            transparent system operations.
    17      PH0     Phase 0 output. Generated from the phase in signal.
    18      RAS     Row address strobe output. Selects proper row when
                    addressing dynamic ram for read/write operations or
                    refresh.
    19      CAS     Column address strobe output. Selects proper column
                    when addressing dynamic memory for read or write
                    operation.
    20      VSS     Ground connection.
    21      PHCL    Color clock, 14.31818 MHZ NTSC.
    22      PHIN    Clock input. Determines the dot transfer rate to the
                    display.
    23-24   A0-A13  Dual function address bus. During a microprocessor read
                    or write operation (AEC = 1), A0 thru A5 are inputs
                    used to address 47 internal registers. When AEC = 0 =
                    O2 is low, then A0 thru A13 are outputs used to refresh
                    dynamic memory.
    35-38   D8-D11  Data bus extension. Color display memory data.
            A8-A11  Address bus extension. Color display memory addressing.
    40      VCC     5VDC input.





















~
                              U9 -12, U21 - 24
                              64K DYNAMIC RAM
                                 901505-01

                                    PIN
                               CONFIGURATION
                                +----------+
                                |          |
                             NC-+ 1      16+-VSS
                            DIN-+ 2      15+-_CAS
                            _WE-+ 3      14+-DOUT
                           _RAS-+ 4      13+-A6
                             A0-+ 5      12+-A3
                             A2-+ 6      11+-A4
                             A1-+ 7      10+-A5
                            VCC-+ 8       9+-A7
                                |          |
                                +----------+


 +------------+------------+------------+--------+--------+--------+---------+
 |COMMODORE   |APPROVED    |VENDOR      |ACCESS  |        |    POWER         |
 |PART        |SOURCE      |PART        |TIME    |CYCLES  |ACTIVE  |STANDBY  |
 |NUMBER      |OF SUPPLY   |NUMBER      |(ns)    |(ns)    |(MW)    |(MAX)(MW)|
 +------------+------------+------------+--------+--------+--------+---------+
 |901505-01   |HITACHI     |HM4864-3    |200     |335     |330     |20       |
 |901505-01   |NEC         |uPD4164-2   |200     |375     |250     |28       |
 |901505-01   |MITSUBISHI  |M5K416NS-20 |200     |330     |275     |28       |
 |901505-01   |MOSTEK      |MK4564N-20  |200     |345     |300     |22       |
 |901505-01   |OKI         |MSM3764-20  |200     |330     |248     |23       |
 |901505-01   |HITACHI     |HM4864P-3   |200     |335     |330     |20       |
 |901505-01   |MATSUSHITA  |MN4164P-20  |200     |330     |275     |27.5     |
 |            |(PANASONIC) |            |        |        |        |         |
 |901505-01   |SIEMENS     |HYB4164-3   |200     |330     |150     |20       |
 |901505-01   |SHARP       |LH2164-Z1   |200     |330     |248     |28       |
 |901505-01   |HITACHI     |HM4864AP-3  |200     |330     |242     |20       |
 |901505-01   |TOSHIBA     |TMM4164AP-20|200     |330     |275     |22       |
 +------------+------------+------------+--------+--------+--------+---------+




[Figure: DRAM functional diagram]



                                                                           33