Apple Design Keyboard

AppleDesign Keyboard
AppleDesign Keyboard M2980 with fixed ADB cable
Manufacturer	Apple Computer, Inc. / NMB / Alps Electric
Type	Computer keyboard
Discontinued	1998
Price	US$99 (retail)
Interface	Apple Desktop Bus
Compatible	All ADB-equipped Macs (System 6.0.7 or later)
Dimensions	470 mm W × 180 mm D × 38 mm H
Weight	1.45 kg (3.2 lbs)
Predecessor	Apple Extended Keyboard II
Successor	Apple USB Keyboard
Model	M2980

The AppleDesign Keyboard (model M2980) was Apple's first cost-reduced full-size keyboard, introduced in 1994 as a replacement for the mechanical Apple Extended Keyboard II. The keyboard marked Apple's transition from Alps mechanical switches to rubber dome technology, significantly reducing manufacturing costs while maintaining a standard 105-key layout. Production occurred across multiple facilities including NMB in Thailand, Alps Electric in Mexico and Czech Republic, and various Chinese manufacturers, resulting in at least four distinct variants with different keycap mounting systems and internal construction. The keyboard featured a permanently attached ADB cable and single ADB port, departing from the dual-port design of its predecessors.

Development Background

The AppleDesign Keyboard emerged from Apple's cost-reduction initiatives following years of financial losses in the early 1990s. Engineering teams were directed to create a keyboard that could be manufactured for under $15 while maintaining acceptable typing quality. The project aimed to bundle a full-size keyboard with consumer Macintosh models without significantly impacting system pricing.

The design process involved evaluating multiple rubber dome technologies from established manufacturers. NMB Technologies and Alps Electric both submitted prototypes using their proprietary dome-with-slider mechanisms. Apple ultimately approved both designs, leading to parallel production arrangements that created the multiple variants found in the market. This dual-sourcing strategy ensured supply stability while driving competitive pricing between manufacturers.

The keyboard's aesthetic design followed Apple's established Snow White language but simplified construction details. The curved case profile of previous keyboards was flattened, reducing plastic usage. The elimination of adjustable feet and template posts further reduced complexity. These changes collectively reduced the part count from over 200 components in the Extended Keyboard II to approximately 80 components in the AppleDesign Keyboard.

Physical Design

Case Construction

The keyboard employed a simplified two-piece case design:

• Upper housing: Single-piece ABS plastic in Platinum gray or black
• Lower housing: Flat base with integrated cable channel
• Assembly: 3-8 screws depending on variant (NMB: 8 screws, Alps: 3 screws)
• Feet: Two long rubber strips, non-adjustable
• Cable routing: Fixed cable with strain relief molded into case

Keyboard Layout

Standard 105-key ANSI layout with Apple-specific modifications:

• Function keys: F1-F15 (15 keys versus standard 12)
• Modifier keys: Command (⌘), Option, Control on both sides
• Power key: Separate key with distinctive rectangular keycap
• Navigation cluster: Six-key inverted-T configuration
• Numeric keypad: Standard 17-key with equals sign

Keycap Specifications

AppleDesign Keyboard Keycaps

Keycap materials and manufacturing varied significantly by production facility:

Alps Mexico production:

• Material: ABS plastic
• Legends: Pad printed
• Profile: Modified cylindrical
• Durability: Prone to legend wear

Alps Czech Republic production:

• Material: PBT plastic
• Legends: Dye sublimated
• Profile: Modified cylindrical
• Durability: Superior wear resistance

NMB Thailand production:

• Material: ABS plastic
• Legends: Laser etched
• Profile: Cylindrical with distinct texture
• Mount: Proprietary slider incompatible with Alps

China production:

• Material: ABS plastic
• Legends: Pad printed or laser etched
• Profile: Varies by specific manufacturer
• Quality: Inconsistent across batches

Manufacturing Variants

Variant 1: NMB Thailand

Production years: 1994-1998

• Identification: 8 case screws, bright yellow rubber domes
• Switch type: NMB dome with slider
• Keycap mount: Proprietary NMB slider design
• PCB: Membrane assembly with metal backing plate
• Cable: Fixed, exits through molded channel
• Build quality: Generally considered superior

Variant 2: Alps Mexico

Production years: 1994-1997

• Identification: 3 case screws, clear rubber domes
• Switch type: Alps Type 2 membrane dome
• Keycap mount: Alps-compatible slider
• PCB: Self-contained membrane module
• Keycaps: Pad printed ABS, prone to wear
• Assembly: Melted plastic rivet technique for plate retention

Variant 3: Alps Czech Republic

Production years: 1995-1998

• Identification: 3 case screws, PBT keycaps
• Switch type: Alps Type 2 membrane dome
• Keycap mount: Alps-compatible slider
• Keycaps: Dye sublimated PBT (highly desirable)
• Build quality: Excellent keycap durability

AppleDesign Keyboard Variant 4

Variant 4: China Production

Production years: 1996-1998

• Identification: Various screw configurations
• Switch type: Generic rubber dome
• Quality: Variable, generally inferior
• Controller: Often marked "©APPLE, Inc."
• Issues: Higher failure rates reported

Technical Specifications

Physical Dimensions

• Width: 470mm (18.5 inches)
• Depth: 180mm (7.1 inches)
• Height: 38mm (1.5 inches) maximum
• Weight: 1.45kg (3.2 lbs) average
• Cable length: 1.5m (fixed attachment)

Electrical Specifications

• Interface: Apple Desktop Bus (ADB)
• Connector: Single 4-pin mini-DIN port
• Power consumption: 25mA typical, 50mA maximum
• Operating voltage: 4.75V - 5.25V DC
• Data rate: 10 kbit/s maximum
• Device address: Default $2

ADB Implementation

• Handler ID: $02 (standard keyboard)
• Polling rate: 100 Hz maximum
• Key rollover: 2-key minimum, varies by variant
• Port location: Right side of keyboard
• Daisy chain: Single device support only

Environmental Specifications

• Operating temperature: 10°C to 35°C
• Storage temperature: -20°C to 60°C
• Humidity: 20% to 80% non-condensing
• Key durability: 5 million actuations (claimed)

Switch Technology

NMB Dome with Slider

Construction:

• Rubber dome: Bright yellow silicone compound
• Slider: White plastic, guides key movement
• Contact: Conductive carbon pad on dome base
• Membrane: Three-layer polyester with printed traces

Characteristics:

• Actuation force: 65g ± 10g
• Travel: 3.5mm total
• Tactile feedback: Moderate collapse point
• Sound: Relatively quiet operation
• Durability: 5 million rated actuations

Alps Type 2 Membrane Dome

Construction:

• Rubber dome: Clear silicone material
• Housing: Individual dome chambers
• Slider: Alps-compatible mount
• Membrane: Integrated module design

Characteristics:

• Actuation force: 60g ± 10g
• Travel: 3.8mm total
• Tactile feedback: Softer than NMB variant
• Sound: Slightly louder than NMB
• Mounting: Screws to keyboard base

Generic Rubber Dome (China variants)

Construction:

• Variable designs from multiple suppliers
• Generally lower-quality materials
• Simplified membrane construction
• Cost-optimized components

Characteristics:

• Actuation force: 55-70g (inconsistent)
• Travel: 3.0-4.0mm (varies)
• Tactile feedback: Poor to moderate
• Durability: Often below specifications

Internal Construction

AppleDesign Keyboard Membrane Assembly

Membrane Assembly

The keyboard utilized a three-layer membrane system:

Top layer: Polyester sheet with conductive traces for each key position

• Thickness: 0.1mm
• Material: PET with silver-based conductive ink
• Connection: Tail connector to controller PCB

Spacer layer: Perforated polyester providing separation

• Thickness: 0.2mm
• Holes: Aligned with key positions
• Purpose: Prevents unintended contact

Bottom layer: Polyester sheet with return traces

• Thickness: 0.1mm
• Material: Matching top layer specifications
• Grounding: Connected to common ground

PCB and Controller

Controller chip: Custom Apple ASIC or licensed design

• Marking: Often "©APPLE, Inc." on generic variants
• Function: Matrix scanning and ADB protocol handling
• Package: 40-pin DIP or surface-mount equivalent

Supporting components:

• Crystal oscillator: 6MHz typical
• Capacitors: Minimal filtering components
• Resistors: Pull-up network for matrix scanning
• Connector: ADB port mounted to separate PCB

Metal Backing Plate

Most variants included a metal plate for rigidity:

• Material: Steel, 0.8mm thickness
• Finish: Zinc plated or painted
• Attachment: Screws or melted plastic rivets
• Purpose: Prevents keyboard flex during typing

Common Issues and Diagnostics

Membrane Failures

Membrane-Related Problems

Symptom	Cause	Diagnostic Method	Repair Approach
Keys not registering	Membrane trace break	Continuity testing with multimeter	Conductive paint repair
Multiple keys activated	Membrane short circuit	Visual inspection for damage	Isolate and cut damaged traces
Intermittent key response	Oxidized contacts	Clean with isopropyl alcohol	Disassemble and clean thoroughly
Entire row/column dead	Matrix line failure	Trace matrix connections	Jumper wire repair
Ghost keys	Membrane contamination	Check for liquid damage	Full membrane replacement

Rubber Dome Deterioration

Dome-Related Issues

Problem	Symptoms	Cause	Solution
Dome collapse	Key stays depressed	Material fatigue	Replace individual dome
Torn dome	No spring back	Physical damage	Glue repair or replacement
Hardened domes	Excessive force required	Age/heat exposure	Full dome sheet replacement
Dome detachment	Key feels loose	Adhesive failure	Reattach with silicone adhesive

Diagnostic Procedures

Basic functionality test:

1. Connect keyboard to known-good ADB Mac
2. Open Key Caps desk accessory
3. Test each key systematically
4. Note any non-responsive or erratic keys
5. Check modifier key combinations

Membrane continuity testing:

1. Disassemble keyboard completely
2. Separate membrane layers carefully
3. Set multimeter to continuity mode
4. Test traces from key pad to connector
5. Map any broken connections

Matrix mapping:

1. Identify row and column lines
2. Create grid diagram of key matrix
3. Test each intersection point
4. Identify patterns in failures
5. Determine if controller or membrane issue

Repair Procedures

Membrane Trace Repair

Materials required:

• Conductive paint (silver-based)
• Isopropyl alcohol 99%
• Cotton swabs
• Fine brush or toothpick
• Multimeter for testing

Procedure:

1. Locate break in trace using continuity testing
2. Clean area with isopropyl alcohol
3. Allow complete drying (30 minutes)
4. Apply thin layer of conductive paint
5. Bridge break with multiple thin coats
6. Allow 24 hours curing time
7. Test continuity before reassembly
8. Apply second coat if resistance too high

AppleDesign Keyabord Rubber Domes

Rubber Dome Replacement

Individual dome repair:

1. Remove affected keycap and slider
2. Carefully extract damaged dome
3. Clean mounting surface thoroughly
4. Test fit replacement dome
5. Apply small amount of silicone adhesive
6. Position dome precisely over contact point
7. Allow 24 hours cure time
8. Test key action before full reassembly

Complete dome sheet replacement:

1. Source compatible dome sheet (difficult)
2. Remove all keycaps systematically
3. Document slider orientations
4. Remove metal backing plate
5. Replace entire dome sheet assembly
6. Reassemble in reverse order
7. Test all keys before case closure

Cleaning Procedures

Basic cleaning:

1. Remove keycaps with puller tool
2. Vacuum loose debris
3. Clean keycaps in warm soapy water
4. Wipe case with damp cloth
5. Clean between switches with cotton swabs
6. Allow complete drying before reassembly

Deep cleaning for liquid damage:

1. Complete disassembly required
2. Rinse membrane with distilled water
3. Clean with 99% isopropyl alcohol
4. Dry thoroughly (48 hours minimum)
5. Inspect for corrosion damage
6. Test before reassembly
7. Consider membrane replacement if extensive damage

Cable Repair

The fixed cable design created a common failure point:

Strain relief failure:

1. Inspect cable at case entry point
2. Check for internal wire breaks
3. Test continuity of each conductor
4. Splice in replacement cable if needed
5. Reinforce with heat shrink tubing
6. Secure with hot glue at entry point

Complete cable replacement:

1. Disassemble keyboard completely
2. Desolder cable from PCB
3. Source compatible 4-conductor cable
4. Solder new cable maintaining pinout
5. Test ADB communication
6. Reinstall with improved strain relief

Controller and PCB Issues

Controller Chip Failures

Controller Diagnostics

Symptom	Test Method	Likely Cause	Repair Option
No ADB communication	Check voltage at chip	Dead controller	Replace keyboard
Random key outputs	Monitor ADB data	Corrupted firmware	No repair possible
Stuck keys	Test matrix scanning	Controller hang	Power cycle, check clock
Missing keys	Map matrix pattern	Bad I/O pin	Controller replacement

AppleDesign Keyboard (NMB) Controller Board

PCB Repair Techniques

Trace repair:

1. Locate broken trace visually
2. Scrape solder mask from trace ends
3. Bridge with 30AWG wire
4. Secure with hot glue
5. Test continuity

Component replacement:

• Crystal oscillator: 6MHz standard
• Capacitors: Match values exactly
• Resistors: 1/4W carbon film typical
• ADB connector: Harvest from donor

Disassembly Guide

Tools Required

• Phillips screwdriver #1
• Flat-blade screwdriver (small)
• Plastic spudgers
• Keycap puller
• Anti-static mat
• Container for screws

NMB Variant Disassembly

1. Remove all keycaps systematically
2. Document any non-standard key positions
3. Remove 8 Phillips screws from bottom
4. Separate case halves carefully
5. Disconnect membrane tail from PCB
6. Remove metal backing plate screws
7. Lift membrane assembly as unit
8. Access controller PCB if needed

Alps Variant Disassembly

1. Remove keycaps and document positions
2. Remove 3 Phillips screws from bottom
3. Note longer rear screw locations
4. Separate case halves at rear first
5. Carefully detach membrane module
6. Module removes as complete unit
7. Metal plate attached with melted rivets
8. Break rivets carefully if membrane access needed

Reassembly Considerations

• Ensure membrane properly seated
• Check cable routing before closing
• Verify no pinched wires
• Test before final screw installation
• Apply even pressure when closing case
• Check all keys for proper action

Preventive Maintenance

Regular Maintenance Schedule

Monthly:

• External cleaning with compressed air
• Wipe case with slightly damp cloth
• Check cable for damage

Quarterly:

• Remove and clean keycaps
• Inspect for debris under keys
• Test all keys for proper function
• Clean ADB port contacts

Annually:

• Complete disassembly and cleaning
• Inspect membrane for wear
• Check rubber dome condition
• Lubricate stabilizer bars if present

Environmental Considerations

Storage recommendations:

• Temperature: 15-25°C optimal
• Humidity: 40-60% to prevent degradation
• Position: Flat, keys facing up
• Protection: Cover to prevent dust
• Cable: Avoid tight coiling

Usage environment:

• Keep away from liquids
• Avoid extreme temperatures
• Prevent dust accumulation
• Maintain stable surface
• Regular cleaning essential

Modern Compatibility

ADB to USB Conversion

Adapter compatibility:

• Griffin iMate: Works but discontinued
• Wombat: Recommended current solution
• TMK converter: DIY option available
• Generic adapters: Often problematic

Conversion issues:

• Power key may not function
• Special keys require remapping
• Some key combinations unsupported
• Latency typically 2-3ms added

Operating System Support

• Mac OS 9: Full native support
• Mac OS X: Through 10.3 with adapter
• Windows: Limited with adapter
• Linux: Possible with configuration
• Modern macOS: Not recommended

Replacement Parts Sources

Available Components

Keycaps:

• Individual keys: Rarely available
• Complete sets: Donor keyboards only
• Compatibility: Variant-specific

Rubber domes:

• Individual: Can adapt from other keyboards
• Complete sheets: Not commercially available
• Alternative: Harvest from similar keyboards

Membranes:

• OEM replacement: Unavailable
• Repair materials: Conductive paint/pens
• Donor sources: Other M2980 keyboards

Cables:

• Direct replacement: Not available
• Generic ADB: Can be adapted
• Repair supplies: Heat shrink, wire

Donor Keyboard Sources

• Similar rubber dome Apple keyboards
• Contemporary third-party ADB keyboards
• Membrane assemblies rarely interchangeable
• Controller chips not available separately

Quality Assessment

Variant Comparison

Manufacturing Variant Quality

Aspect	NMB Thailand	Alps Czech	Alps Mexico	China Generic
Build quality	Excellent	Good	Good	Variable
Keycap durability	Good	Excellent (PBT)	Poor	Poor
Dome quality	Excellent	Good	Good	Variable
Failure rate	Low	Low	Moderate	High
Repairability	Moderate	Moderate	Difficult	Poor
Collector value	Moderate	High (PBT)	Low	Minimal

Known Reliability Issues

• Fixed cable prone to strain failure
• Membrane traces vulnerable to liquid damage
• Rubber domes harden with age
• Keycap legends wear (except PBT variant)
• Single ADB port limits expandability

Service Life Expectancy

Component Lifespans

• Rubber domes: 5-10 years typical
• Membrane: 10-15 years without liquid exposure
• Controller: 20+ years
• ADB cable: 5-10 years with strain
• Keycaps: Varies significantly by material

Failure Progression

1. Keycap legend wear (1-3 years heavy use)
2. Cable strain relief degradation (3-5 years)
3. Rubber dome hardening (5-10 years)
4. Membrane trace oxidation (10-15 years)
5. Complete membrane failure (15-20 years)

See Also

• Apple Extended Keyboard II
• Apple Desktop Bus
• Rubber Dome Keyboard Repair
• Membrane Keyboard Maintenance