Apple Mouse IIc

Apple Mouse IIc
Apple Mouse IIc in cream-beige color
Manufacturer	Apple Computer, Inc.
Type	Computer mouse
Discontinued	1988
Price	$125 (with MousePaint software)
Interface	DE-9 connector (dual-purpose port)
Compatible	Apple IIc, IIe (with card), Macintosh
Dimensions	2.5" W × 3.7" L × 1.3" H
Weight	140g (4.9 oz)
Predecessor	None (first IIc mouse)
Successor	Platinum Apple Mouse IIc
Model	M0100, A2M4015, A2M4035

The Apple Mouse IIc was a computer mouse designed specifically for the Apple IIc computer, introduced in April 1984. While sharing the M0100 model number with the Macintosh Mouse initially, it featured distinct internal electronics to identify itself to the IIc's dual-purpose joystick/mouse port. The mouse underwent several revisions through its production run, with model numbers changing from M0100 to A2M4015 and finally A2M4035 for the platinum version. Its cream-beige color scheme and sleeker profile distinguished it from its Macintosh counterpart, while its cross-platform compatibility made it unique among Apple mice of the era.

Development and Purpose

Background

The Apple IIc, introduced in April 1984, was designed as a compact, portable version of the Apple IIe. Unlike the IIe which required a separate mouse interface card, the IIc featured a built-in dual-purpose port that could accept either a joystick or mouse. This design decision required special consideration for the mouse hardware.

The dual-purpose port presented a technical challenge: the computer needed to distinguish between a joystick and a mouse when either was connected. Apple's solution was to design a mouse with specific identification circuitry that would signal to the IIc what type of device was connected.

Design Requirements

The IIc mouse needed to:

• Send identification signals to the dual-purpose port
• Maintain compatibility with existing mouse software
• Match the IIc's cream-beige aesthetic
• Provide reliable operation without a dedicated mouse port
• Be manufacturable at reasonable cost

Model Variations

Original M0100 Version (1984)

The first Apple Mouse IIc carried the same M0100 model number as the Macintosh Mouse but was distinctly different:

Physical characteristics:

• Color: Cream-beige to match IIc case
• Button: Matching cream color (not contrasting)
• Cable: Cream-colored cable
• Profile: Sleeker, less blocky than Mac version
• Surface: Smooth, uniform texture

Internal differences:

• Identification resistors for IIc detection
• Modified encoder circuitry
• Different PCB layout
• Special signaling components

A2M4015 Version (1985-1987)

In 1985, Apple updated the model number and made minor revisions:

Changes:

• New model designation: A2M4015
• Label simply read "Mouse" (not "Mouse IIc")
• Minor internal component updates
• Improved manufacturing consistency
• Often sold boxed with MousePaint software

Packaging:

• Included user manual
• MousePaint disk (3.5" or 5.25")
• Packing list
• Registration card

A2M4035 Platinum Version (1988)

The final version adopted Apple's platinum color scheme:

Updates:

• Platinum gray color matching late IIc models
• Identical appearance to Platinum Macintosh Mouse
• USA-manufactured versions work on IIc
• Improved internal components
• Better cross-platform compatibility

Technical Specifications

Physical Specifications

Dimensions:

• Width: 2.5 inches (64mm)
• Length: 3.7 inches (94mm)
• Height: 1.3 inches (33mm)
• Cable length: 4 feet (1.2m)
• Weight: 140g (4.9 oz) without cable

Tracking mechanism:

• Type: Opto-mechanical
• Ball: Rubber-coated steel, 22mm diameter
• Resolution: 100 counts per inch
• Tracking speed: Up to 10 inches/second
• Encoder wheels: Slotted optical type

Electronic Design

Identification Circuit

The key difference between the IIc mouse and other Apple mice was the identification circuit:

Components:

• Resistor networks for port identification
• RN1: 10KΩ network near switch
• RN2: 620Ω network near ball area
• SN74LS14N hex Schmitt trigger inverter
• Additional pull-up resistors on signal lines

Identification method: The IIc detected the mouse by checking resistance values on specific pins:

• Pin combinations created unique resistance signature
• Different from joystick resistance values
• Allowed automatic device detection
• No user configuration required

Signal Processing

Optical sensors:

• Type: 3-pin infrared sensors
• Output: Push-pull configuration
• No external pull-up resistors needed
• Direct drive capability for IIc inputs

Signal conditioning:

• Schmitt trigger for signal cleanup
• Resistor networks for level adjustment
• Compatible with IIc's NE556 timer inputs
• Provided clean quadrature signals

Connector and Pinout

The Mouse IIc used a DE-9 connector with the following pinout:

Pin	Signal	Function
1	+5V	Power supply
2	SW0	Mouse identification
3	GND	Ground
4	X2	X-axis quadrature 2
5	SW1	Button signal
6	n/c	Not connected
7	Y2	Y-axis quadrature 2
8	X1	X-axis quadrature 1
9	Y1	Y-axis quadrature 1

Connector characteristics:

• 5 pins top row, 3 pins bottom row configuration
• Different internal wiring than Mac mouse
• Special resistance values for identification

Compatibility

System Compatibility

Native support:

• Apple IIc (all versions)
• Apple IIc Plus

With Mouse Interface Card:

• Apple II
• Apple II Plus
• Apple IIe
• Apple IIGS

Cross-platform compatibility:

• All Macintosh computers with DE-9 port
• Lisa 2/Macintosh XL
• Works as standard mouse on these systems

Software Compatibility

Apple IIc software:

• MousePaint (bundled)
• MouseDesk
• MouseWrite
• The Print Shop
• Various educational titles
• ProDOS applications with mouse support

Cross-platform notes:

• Functions as standard mouse on Macintosh
• No special drivers needed for Mac use
• Identification resistors don't affect Mac operation

Compatibility Issues

Early Mac Mouse on IIc

Some early Macintosh mice (M0100) don't work properly on the IIc:

Problem mice:

• Early Alps-manufactured M0100
• Some Taiwan-produced versions
• Mice with open-collector outputs

Symptoms:

• Not recognized by IIc
• Erratic cursor movement
• No response at all

Technical cause:

• Weak output drive capability
• Cannot overcome IIc's pull-up resistors
• Insufficient current to trigger NE556 inputs

Solutions

Hardware modifications:

• Replace comparator chip with push-pull output type
• Change µPC339 to TLC3704IN
• Modify pull-up resistor values
• Add buffer ICs

Alternative solutions:

• Use Apple Mouse IIc instead
• Use later USA-made M0100 versions
• Purchase IIc-specific mouse
• Use adapter devices

Internal Construction

Disassembly

Tools required:

• Small Phillips screwdriver
• Plastic spudger
• Patience (tight clips)

Procedure:

1. Remove single screw from button area
2. Locate clips on strain relief sides
3. Use spudger to release side clips (very tight)
4. Separate case halves carefully
5. Note component positions before removal

Reassembly notes:

• Ensure encoder wheels properly seated
• Check cable routing
• Verify clips fully engaged
• Test before final screw installation

Component Layout

Main PCB components:

• Microswitch: Omron SS-01-FD
• Logic IC: SN74LS14N (hex Schmitt trigger)
• Resistor network 1: 10KΩ (E10KΩ8433)
• Resistor network 2: 620Ω (E620Ω8432)
• Optical sensors: 3-pin IR type
• Various discrete components

Mechanical components:

• Ball cage assembly
• X and Y axis rollers
• Encoder wheels with slots
• Spring-loaded roller arms
• Ball retainer ring

Common Issues and Repairs

Mechanical Problems

Common Mouse IIc Problems

Issue	Symptoms	Cause	Solution
Not recognized	IIc doesn't detect mouse	Failed ID resistors	Check/replace resistor networks
Erratic tracking	Cursor jumps around	Dirty sensors/ball	Clean thoroughly with alcohol
No X or Y movement	Single axis failure	Broken encoder wheel	Replace wheel or harvest from donor
Button failure	Click not registering	Worn Omron switch	Replace with SS-01-FD or equivalent
Intermittent operation	Works sometimes	Loose internal connections	Resolder connections
Cable problems	Connection issues	Strain relief failure	Repair cable or replace

Diagnostic Procedures

Initial testing:

1. Connect to Apple IIc
2. Boot with MousePaint or compatible software
3. Check if mouse is recognized
4. Test movement in all directions
5. Verify button operation
6. Check for smooth tracking

Advanced diagnostics:

1. Measure resistance between ID pins
2. Check for proper values (10KΩ and 620Ω)
3. Test continuity of all connections
4. Verify optical sensor operation
5. Check Schmitt trigger outputs

Cleaning Procedures

Basic cleaning:

1. Remove ball and retainer ring
2. Clean ball with mild soap and water
3. Clean rollers with isopropyl alcohol
4. Remove debris from ball cavity
5. Clean optical sensors with swab
6. Reassemble when completely dry

Deep cleaning:

1. Disassemble mouse completely
2. Clean PCB with isopropyl alcohol
3. Clean encoder wheels carefully
4. Check and clean all optical paths
5. Inspect and clean connector pins
6. Test before reassembly

Component Replacement

Button Switch

Original part: Omron SS-01-FD Modern equivalent: Still available from Mouser Alternative: Any compatible 6mm tactile switch

Replacement procedure:

1. Desolder original switch
2. Clean PCB pads thoroughly
3. Install new switch
4. Ensure proper orientation
5. Test click action

Resistor Networks

If identification fails:

1. Test resistance values
2. Replace if out of specification
3. RN1: 10KΩ SIP resistor network
4. RN2: 620Ω SIP resistor network
5. Verify proper installation

Cable Repair

Common failure points:

• Strain relief exit
• Near connector
• Internal wire breaks

Repair method:

1. Identify break location
2. Disassemble if internal
3. Splice or replace cable
4. Ensure proper color coding
5. Test all connections

Maintenance

Regular Maintenance

Preventive care schedule:

Weekly (heavy use):

• Wipe ball with clean cloth
• Check for smooth operation

Monthly:

• Remove and clean ball
• Inspect rollers for debris
• Test button responsiveness

Quarterly:

• Deep clean mechanism
• Check cable condition
• Clean connector pins

Annually:

• Full disassembly and service
• Replace worn components
• Document condition

Storage

Long-term storage:

• Clean thoroughly before storage
• Remove ball to prevent flat spots
• Store in anti-static bag
• Protect from temperature extremes
• Avoid humidity exposure
• Coil cable loosely

Environmental conditions:

• Temperature: 10-30°C optimal
• Humidity: 30-60% RH
• Avoid direct sunlight
• Protect from dust
• Prevent chemical exposure

Modifications

Improving Mac Mouse Compatibility

For Mac mice that don't work on IIc:

TLC3704IN chip swap:

1. Remove µPC339 comparator
2. Install TLC3704IN (pin compatible)
3. Provides push-pull outputs
4. Drives IIc inputs properly
5. No other modifications needed

Alternative: Add buffer IC:

1. Install 74LS244 buffer chip
2. Wire between sensors and outputs
3. Provides adequate drive current
4. More complex modification

USB Conversion

Modern conversion options:

• Arduino-based converters
• Commercial adapters (rare)
• Custom microcontroller solutions

Conversion maintains:

• Original appearance
• Button functionality
• Reasonable tracking accuracy
• USB HID compatibility

Software

MousePaint

MousePaint was the bundled software with the Mouse IIc:

Features:

• Full painting application
• Pattern fills
• Shape tools
• Text support
• File save/load
• Printer support

System requirements:

• Apple IIc with mouse
• 128K RAM
• One disk drive
• Color or monochrome display

Other Mouse Software

Productivity:

• MouseWrite - Word processor
• MouseCalc - Spreadsheet
• MouseDesk - Desktop environment

Graphics:

• Dazzle Draw
• Blazing Paddles
• The Print Shop

Educational:

• Various MECC titles
• Reader Rabbit series
• Math Blaster

Production Information

Manufacturing

Production timeline:

• 1984: M0100 version introduced
• 1985: A2M4015 revision
• 1987: Continued production
• 1988: A2M4035 platinum version
• 1988: End of production

Manufacturing locations:

• USA (later versions)
• Taiwan (some versions)
• Various contractors

Packaging

Retail package contents:

• Apple Mouse IIc
• MousePaint software
• User manual
• Quick reference card
• Registration card
• Warranty information

Box variations:

• Early: Simple packaging
• Later: Colorful retail box
• Software bundle versions
• OEM versions for IIc

Collecting

Identification

Model identification:

• Check bottom label
• M0100: Early version
• A2M4015: Most common
• A2M4035: Platinum version

Date determination:

• Component date codes
• PCB revision marks
• Serial number patterns

Preservation

Best practices:

• Clean before storage
• Prevent UV exposure
• Control humidity
• Regular exercise if functional
• Document serial numbers
• Preserve original components

See Also

• Apple IIc
• Apple Mouse (M0100)
• Apple II Mouse Interface Card
• Apple Desktop Bus Mouse