Apple Mouse

Apple Mouse
Apple Mouse M0100 (Beige version)
Manufacturer	Apple Computer, Inc. / Alps Electric / Logitech
Type	Computer mouse
Discontinued	October 1987
Price	$35 (standalone)
Interface	DE-9 connector
Compatible	Macintosh 128K through Plus, Lisa 2
Dimensions	2.75" W × 3.8" L × 1.4" H
Weight	150g (5.3 oz)
Predecessor	Apple Lisa Mouse
Successor	Apple Desktop Bus Mouse
Model	M0100

The Apple Mouse (model M0100) was the computer mouse shipped with the original Macintosh computer in 1984. Based on the earlier Lisa Mouse design but with cost-reduced components and manufacturing, it became the mouse that popularized graphical user interfaces and established the mouse as an essential computer peripheral. The M0100 was manufactured in several variations between 1984 and 1987, with an estimated 1.7 million units produced. Its single-button design and quadrature encoding mechanism established design principles that Apple would maintain for decades.

Development History

Origins

The M0100's development directly followed the Lisa Mouse (A9M0050) introduced in 1983. Apple's engineering team, led by Bill Dresselhaus and the industrial design group, needed to create a lower-cost mouse for the Macintosh while maintaining reliability and user experience. The target manufacturing cost was reduced from the Lisa Mouse's $50 to approximately $15 per unit.

Key design decisions included:

• Replacing the Lisa's steel ball with a rubber-coated steel ball for better traction
• Simplifying the internal mechanism while maintaining quadrature encoding
• Reducing the number of internal components
• Streamlining the manufacturing process

The mouse was co-developed with Alps Electric and later manufactured by multiple suppliers including Logitech, leading to several internal variations while maintaining the same model number and external functionality.

Design Philosophy

The single-button design was a deliberate choice by Apple, despite Xerox's three-button mouse precedent. Steve Jobs and the Mac team believed that a single button would be less intimidating to computer novices and would force software developers to create more intuitive interfaces. This philosophy required the Mac operating system to use keyboard modifiers (Command, Option, Shift) in combination with mouse clicks to achieve additional functionality.

Physical Design

External Characteristics

The M0100 featured a rectangular design with rounded edges that matched the Macintosh's design language:

Case design:

• Material: ABS plastic
• Colors: Beige (1984-1987), Platinum gray (1987)
• Surface texture: Smooth with slight texture on sides
• Button: Large rectangular surface occupying front third
• Logo: Embossed Apple logo on button surface

Dimensions:

• Width: 2.75 inches (70mm)
• Length: 3.8 inches (97mm)
• Height: 1.4 inches (36mm)
• Cable length: 4 feet (1.2m)
• Weight: 150g without cable

Ergonomics:

• Ambidextrous design
• Low profile for palm grip
• Textured sides for grip
• Large button area for easy clicking

Color Variations

Standard Macintosh version:

• Case: Beige (Pantone 453C)
• Button: Slightly darker brown
• Cable: Dark gray "Smoke" color
• Ball: Black or gray depending on version

Platinum version (1987):

• Case: Platinum gray (Pantone 427C)
• Button: Matching platinum
• Cable: Darker gray
• Ball: Gray

Apple IIc version:

• Case: Cream-beige (lighter than Mac version)
• Button: Matching cream color
• Cable: Matching light color
• Sleeker profile than Mac version

Internal Mechanism

Quadrature Encoding System

The M0100 used quadrature encoding to track movement:

Components:

• Rubber-coated steel ball (22mm diameter)
• Two perpendicular rollers (X and Y axes)
• Two slotted encoder wheels
• Four infrared LEDs (two per axis)
• Four photodetectors
• Simple logic board with encoder chip

Operation principle:

1. Ball movement rotates against spring-loaded rollers
2. Rollers turn encoder wheels with radial slots
3. Slots alternately block and pass infrared light
4. Photodetectors generate two square waves per axis
5. Phase relationship between waves indicates direction
6. Pulse frequency indicates speed

Technical specifications:

• Resolution: 100 counts per inch (cpi)
• Maximum tracking speed: 10 inches/second
• Sampling rate: 100 Hz
• Quadrature states: 4 per slot

Button Mechanism

Microswitch specifications:

• Type: Mechanical snap-action
• Manufacturer: Alps or Omron (varies)
• Actuation force: 65-85 grams
• Lifespan: 1 million clicks rated
• Travel: 0.5mm to actuation
• Audible click feedback

Button assembly:

• Plastic lever arm design
• Spring return mechanism
• Adjustable actuation point (some versions)
• Direct microswitch activation

Manufacturing Variations

Despite carrying the same M0100 model number, several distinct internal variations were produced:

Version 1: Early Production (1984)

Identification:

• Two screws near cable end
• "Copyright 1983" on PCB
• Square IC chips
• Black ball

Manufacturer: Alps Electric Location: Japan Mechanism: Heavy-duty encoder wheels Cable: Non-detachable, strain relief boot

Version 2: Mid Production (1985-1986)

Identification:

• Single screw at front
• Simplified PCB layout
• Cost-reduced components
• Black or gray ball

Manufacturer: Multiple (Alps, others) Location: Taiwan, Japan Changes: Lighter encoder wheels, simplified assembly Cable: Improved strain relief

Version 3: Late Production (1986-1987)

Identification:

• Two screws (different positions)
• Further simplified internals
• Some with detachable cable
• Gray ball standard

Manufacturer: Logitech (primarily) Location: Taiwan, Ireland Changes: Final cost reductions Notable: Some units pre-assembled for Plus

Version 4: Platinum (1987)

Identification:

• Platinum gray color
• Matching Mac Plus styling
• Otherwise identical to Version 3
• Gray ball only

Manufacturer: Various Production: Limited run Purpose: Color coordination with platinum Macs

Interface and Protocol

DE-9 Connector

The M0100 used a 9-pin D-subminiature connector:

Pinout:

Pin	Signal	Description
1	GND	Ground
2	+5V	Power supply
3	GND	Ground
4	X2	X-axis quadrature signal 2
5	X1	X-axis quadrature signal 1
6	n/c	Not connected
7	SW-	Button signal (active low)
8	Y2	Y-axis quadrature signal 2
9	Y1	Y-axis quadrature signal 1

Electrical characteristics:

• Logic levels: TTL (0-5V)
• Current draw: 50mA typical
• Pull-up resistors: Internal to Mac
• Maximum cable length: 6 feet

Communication Protocol

Quadrature signals:

• Two square waves per axis
• 90-degree phase offset
• Direction from phase relationship
• Speed from frequency

Decoding sequence:

1. Previous state stored
2. Current state read
3. Compare states to determine direction
4. Increment/decrement position counter
5. Report to operating system

Button handling:

• Hardware interrupt on press
• Debouncing in hardware
• Software handling of click/drag

Common Issues and Diagnostics

Mechanical Problems

Common M0100 Problems and Solutions

Issue	Symptoms	Cause	Solution
Erratic cursor	Jumping, stuttering movement	Dirty ball/rollers	Clean with isopropyl alcohol
No X or Y movement	Cursor moves one axis only	Broken encoder wheel	Replace wheel or mouse
Intermittent tracking	Works sometimes	Dirty encoder slots	Disassemble and clean thoroughly
Double-clicking	Single click registers twice	Worn microswitch	Replace switch
No clicking	Button press not detected	Failed microswitch	Replace switch
Cable issues	Intermittent connection	Strain at connector	Repair or replace cable

Diagnostic Procedures

Visual inspection:

1. Check cable for obvious damage
2. Inspect connector pins for bending
3. Look for case cracks
4. Check ball for flat spots

Functional testing:

1. Connect to known-good Mac
2. Open Mouse control panel
3. Test all directions of movement
4. Verify smooth tracking
5. Test button operation
6. Check for double-click issues

Internal inspection:

1. Remove ball and check rollers
2. Look for debris in ball cavity
3. Check encoder wheels for damage
4. Inspect photodetectors for dust
5. Verify cable continuity

Repair Procedures

Cleaning

Basic cleaning:

1. Turn mouse upside down
2. Rotate retaining ring counterclockwise
3. Remove ball and ring
4. Clean ball with soap and water
5. Clean rollers with alcohol-dipped swab
6. Remove debris from cavity
7. Reassemble when dry

Deep cleaning:

1. Disassemble mouse completely
2. Clean encoder wheels with compressed air
3. Clean photodetectors with swab
4. Wipe all surfaces with alcohol
5. Check and clean all connections
6. Lubricate roller shafts sparingly

Disassembly Guide

Tools required:

• Small Phillips screwdriver
• Plastic spudgers
• Tweezers
• Isopropyl alcohol (90%+)
• Cotton swabs

Procedure:

1. Remove ball and retaining ring
2. Locate case screws (position varies by version)
3. Remove screws carefully
4. Separate case halves starting at rear
5. Note cable routing and component positions
6. Document before proceeding
7. Lift out PCB assembly carefully

Reassembly notes:

• Ensure encoder wheels seated properly
• Check roller spring tension
• Verify cable routing
• Test before final assembly
• Apply even pressure when closing case

Component Replacement

Microswitch Replacement

Compatible switches:

• Omron D2F series
• Alps SKFL series
• Generic 6mm × 6mm tactile

Replacement procedure:

1. Desolder original switch
2. Clean PCB pads
3. Install new switch
4. Verify orientation
5. Solder carefully
6. Test operation

Encoder Wheel Repair

Common failures:

• Broken teeth on wheel
• Cracked hub
• Worn shaft hole

Repair options:

• Glue broken teeth (temporary)
• 3D print replacement wheel
• Harvest from donor mouse
• Fabricate from thin plastic

Cable Repair

Failure points:

• Strain relief at mouse
• Near connector
• Mid-cable breaks

Repair procedure:

1. Locate break with multimeter
2. Cut cable past break
3. Strip and tin wires
4. Splice with heat shrink
5. Test each connection
6. Reinforce with tape

Roller Restoration

Symptoms of worn rollers:

• Poor tracking
• Requires excessive pressure
• Uneven movement

Restoration methods:

• Clean with alcohol
• Resurface with fine sandpaper
• Apply rubber rejuvenator
• Replace roller assembly
• Harvest from donor mouse

Modifications

Conversion to Optical

Several hobbyists have created optical conversion kits:

Components needed:

• Optical sensor module
• Microcontroller (Arduino Nano)
• 3D printed mounting bracket
• USB cable

Benefits:

• No mechanical maintenance
• Better tracking precision
• USB compatibility
• Preserves original appearance

Installation overview:

1. Remove mechanical components
2. Install optical sensor
3. Mount microcontroller
4. Connect USB cable
5. Configure firmware
6. Calibrate tracking

Adding Right-Click

Hardware modification:

• Add second microswitch
• Wire to unused DE-9 pin
• Modify case for button
• Software support required

Software solutions:

• Click-and-hold for context menu
• Keyboard modifier combinations
• Third-party utilities

USB Conversion

Direct USB conversion:

• Replace DE-9 with USB cable
• Add USB-HID controller
• Maintain quadrature decoding
• Power from USB (5V)

Adapter solutions:

• Commercial DE-9 to USB adapters
• DIY Arduino-based converters
• Maintains original hardware

Maintenance

Preventive Maintenance Schedule

Weekly (heavy use):

• Wipe ball with cloth
• Check for debris

Monthly:

• Remove ball and clean
• Inspect rollers
• Test button operation

Quarterly:

• Deep clean mechanism
• Check cable condition
• Lubricate if needed

Annually:

• Full disassembly
• Component inspection
• Contact cleaning
• Cable stress test

Storage Guidelines

Long-term storage:

• Clean thoroughly first
• Remove ball
• Store in anti-static bag
• Avoid temperature extremes
• Keep in dry environment
• Coil cable loosely

Environmental specifications:

• Operating: 10-40°C, 20-80% RH
• Storage: 0-50°C, 10-90% RH
• Avoid direct sunlight
• Prevent dust accumulation

Restoration Tips

Yellowing reversal:

• Retrobrite treatment possible
• UV exposure method
• Hydrogen peroxide gel
• Monitor carefully
• May affect plastic strength

Case restoration:

• Clean with mild detergent
• Polish scratches carefully
• Replace missing feet
• Restore logo if worn

Compatibility

Computer Compatibility

Native support:

• Macintosh 128K
• Macintosh 512K/512Ke
• Macintosh Plus
• Lisa 2/Macintosh XL
• Apple IIc (IIc version)

With adapters:

• Later ADB Macs (with adapter)
• Modern Macs (USB adapter)
• PCs (with appropriate adapter)
• Apple IIGS (adapter required)

Software Compatibility

System software:

• System 1.0 through 7.5.5 (native)
• Mac OS 8-9 (with adapter)
• Mac OS X (with USB adapter)

Mouse control options:

• Original Mouse control panel
• Tracking speed adjustment
• Double-click speed
• Limited customization options

Production and Sales

Manufacturing Data

Production timeline:

• 1984: Initial production begins
• 1985: Multiple manufacturers added
• 1986: Cost reduction changes
• 1987: Platinum version introduced
• October 1987: Discontinued

Production volumes:

• Estimated 1.7 million total units
• Peak production: 1985-1986
• Multiple manufacturing locations
• Various component suppliers

Manufacturing locations:

• Japan (Alps Electric)
• Taiwan (various contractors)
• Ireland (late production)
• USA (limited assembly)

Market Impact

The M0100 was instrumental in:

• Popularizing the computer mouse
• Establishing GUI as standard interface
• Proving single-button viability
• Setting mouse design standards
• Influencing competitor designs

Collecting

Identification Guide

Serial number locations:

• Bottom label (if present)
• Internal PCB markings
• Date codes on components

Determining version:

1. Check screw configuration
2. Examine PCB layout
3. Note component types
4. Check manufacturing location
5. Ball color indicator

Value Factors

Condition grades:

• Mint: Unused, complete packaging
• Excellent: Minimal use, no yellowing
• Good: Normal wear, functional
• Fair: Heavy wear, works
• Poor: Non-functional or damaged

Value considerations:

• Box and documentation add 50-100% value
• Platinum versions more desirable
• Early versions with black ball premium
• Working condition essential
• Severe yellowing reduces value

Current market values (2024):

• Boxed, mint: $150-250
• Loose, excellent: $50-100
• Loose, good: $25-50
• Parts/repair: $10-25

Preservation

Best practices:

• Store in controlled environment
• Prevent UV exposure
• Regular exercise if functional
• Document serial numbers
• Maintain original components
• Avoid aggressive cleaning

See Also

• Apple Lisa Mouse
• Macintosh 128K
• Apple Desktop Bus Mouse