Apple Desktop Bus Keyboard

Apple Desktop Bus Keyboard
	Apple Desktop Bus Keyboard with Alps SKCM Orange switches
Manufacturer	Apple Computer, Inc.
Type	Computer keyboard
Discontinued	1992
Price	US$129 (retail, keyboard only)
Interface	Apple Desktop Bus
Compatible	Apple IIGS, all ADB-equipped Macs
Dimensions	440 mm W × 140 mm D × 42 mm H (rear)
Weight	0.91 kg (2.0 lbs)
Predecessor	Apple IIe Keyboard (A2M2003)
Successor	Apple Keyboard (M0116) (M0116)
Model	A9M0330, 658-4081

The Apple Desktop Bus Keyboard was the first keyboard to implement Apple's new Apple Desktop Bus interface, introduced alongside the Apple IIGS computer on September 15, 1986. Often referred to as the Apple IIGS Keyboard, it pioneered several Apple firsts: the ADB interface, dual ADB ports for daisy-chaining, an integrated power button, and the introduction of the Snow White design language. The keyboard was manufactured in two distinct variants—one in Japan with Alps switches and another in Taiwan with SMK switches—both sharing the same external appearance but differing significantly in internal construction and keycap manufacturing methods.

Historical Context

The Apple Desktop Bus Keyboard represented a convergence of Apple's computer lines, bridging the Apple II and future Macintosh families. Developed during 1985-1986 as part of the Apple IIGS project, it embodied Apple's vision for a unified peripheral ecosystem. The keyboard introduced the ADB interface months before it appeared on any Macintosh computer, establishing the protocol that would serve Apple for the next thirteen years.

The keyboard's design marked Apple's first implementation of the Snow White design language developed by Hartmut Esslinger's Frog Design team. The introduction of "Platinum" gray coloring on the IIGS and its peripherals established the color scheme that would define Apple products through the 1990s. This represented a significant departure from the beige computers of the early 1980s, positioning Apple as a design-focused company.

Design Features

Physical Design

The keyboard embodied the Snow White design language principles:

Horizontal grooves: Decorative lines creating visual texture
Slanted profile: Front-to-back angle for ergonomic typing
Platinum coloring: Warm gray tone (Pantone 423C equivalent)
Unified aesthetic: Matched Apple IIGS system unit design

The 81-key layout represented a transitional design, incorporating elements from both Apple II and Macintosh keyboard traditions:

Escape key: First appearance on an Apple keyboard
Control key: Positioned left of 'A' (Apple II tradition)
Command keys: Open and closed Apple logos
Option key: Introduced for special characters
Power button: Upper right corner position

Layout Peculiarities

Several non-standard key arrangements distinguished this keyboard:

Arrow keys: Single row arrangement (← → ↓ ↑)
Tilde/Grave: Positioned left of spacebar
Caps Lock: Lower left corner placement
Delete key: Labeled as "Delete" (not Backspace)
Return key: Backward L-shape configuration

Manufacturing Variants

Japan Variant (658-4081)

Production Period: 1986-1991

Identification:

Label marked "Made in Japan"
Part number 658-4081 or 825-1301-A
Early units: Simple rear label
Later units: A9M0330 designation added

Switch Technology:

Early production (1986-1989): Alps SKCM Orange
- Orange-colored sliders
- Tactile, non-clicky operation
- 70g actuation force

Late production (1989-1991): Alps SKCM Salmon
- Pink-salmon colored sliders
- Identical feel to Orange
- Slightly different internal construction

Keycaps:

Material: PBT plastic (except spacebar: ABS)
Manufacturing: Dye sublimation
Color: Uniform platinum gray
Profile: Apple standard (similar to Cherry)
Stabilizers: Brown Alps-type clips

Construction Details:

Internal plate: Steel, painted
PCB: Single-sided with jumper wires
Controller: Custom Apple ASIC
Assembly: Three screws with washers

Taiwan Variant (A9M0330)

Production Period: 1987-1992

Identification:

Label marked "Made in Taiwan"
Model number A9M0330 prominently displayed
Consistent labeling throughout production

Switch Technology:

SMK second-generation Alps mount
- White-colored sliders
- Tactile, non-clicky operation
- 65g actuation force (lighter than Alps)
- Cross-mount compatible with Alps keycaps

Keycaps:

Material: ABS plastic
Manufacturing: Double-shot injection molding
Color: Slightly darker gray than Japan variant
Bottom: Dark gray (two-tone appearance)
Stabilizers: White SMK-type clips

Construction Details:

PCB: Includes EMI shielding (tin foil layer)
Part number: SMK 2J-M9020-02B
Controller: Socketed ROM chip (341-0124)
Assembly: Three screws (washers optional)

Technical Specifications

Physical Specifications

Dimensions: 440mm × 140mm × 42mm
Weight: 0.91kg (Japan) / 0.86kg (Taiwan)
Cable: Coiled ADB, 1.2m extended
Keys 81 total
Typing angle 6 degrees

Electrical Specifications

Interface Apple Desktop Bus (ADB)
Power consumption 25mA typical, 50mA maximum
Operating voltage 4.75V - 5.25V
Data rate 10 kbit/s maximum

ADB Protocol Implementation

Device type Keyboard
Default address $2
Handler ID $01 (Standard protocol)
Registers
- Register 0: Key event data (2 bytes)
- Register 1: Reserved
- Register 2: LED status and modifiers
- Register 3: Device ID and address

Key Matrix

Matrix size 8×11
Rollover 2-key guaranteed
Ghosting prevention Diode per switch
Debounce Hardware (5ms)

Switch Specifications

Alps SKCM Orange/Salmon

Specifications

Type: Tactile, non-clicky
Actuation force: 70g ± 10g
Pre-travel: 2.0mm
Total travel: 3.5mm
Lifespan: 10 million actuations

Characteristics

Smooth tactile bump
Minimal wobble
Consistent feel across keyboard
Self-cleaning contacts

SMK Second Generation

Specifications

Type: Tactile, non-clicky
Actuation force: 65g ± 10g
Pre-travel: 2.0mm
Total travel: 3.5mm
Lifespan: 20 million actuations

Characteristics

Lighter than Alps
More pronounced tactility
Slightly scratchier feel
Cross-mount Alps compatible

Alps SKCL Lock (Caps Lock)

All variants used the Alps SKCL Lock switch:

Mechanical latching mechanism
Physical lock when engaged
Cream or white housing
Not user-replaceable with standard switch

Production Information

Serial Number Format

Japan (658-4081)

Format: NNNNNN (six digits)
Example: 380504, 318537

Taiwan (A9M0330)

Format: PPYWWNNNNNN
PP: Production facility
Y: Year (7=1987, 8=1988, etc.)
WW: Week number
NNNNNN: Sequential number

Production Timeline

1986 Initial release with Apple IIGS (Japan only)
1987 Taiwan production begins
1989 Transition from Orange to Salmon Alps (Japan)
1990 Peak production year
1991 Japan production ends
1992 Final units produced (Taiwan)

Manufacturing Differences

**Component Comparison**
Component	Japan Variant	Taiwan Variant
Switches	Alps SKCM Orange/Salmon	SMK Second Generation
Keycaps	PBT, dye-sublimated	ABS, double-shot
Stabilizers	Brown Alps clips	White SMK clips
PCB	No shielding	EMI foil shielding
ROM	Soldered or socketed	Always socketed
Assembly	Screws with washers	Screws, washers optional
Weight	0.91kg	0.86kg
Production	1986-1991	1987-1992

Keycap Design

Row Profiles

The keyboard used different stem heights for each row:

Number row Tallest stems, switches mounted vertically
QWERTY row Standard height
Home row Slightly shorter
Bottom row Shortest stems
Spacebar Custom profile with multiple mount points

Typography

Font Univers 57 Condensed
Style Regular (not italic like later Apple keyboards)
Alignment Centered on keycap
Special keys Icon-based legends (Command, Option)

Manufacturing Quality

Japan variant (dye-sublimation)

Permanent legends, wear-resistant
Uniform color throughout keycap
PBT resistant to yellowing
Sharp, precise legends

Taiwan variant (double-shot)

Legends cannot wear off
Two-tone appearance (gray top, dark bottom)
ABS prone to yellowing
More structural support for stems

Software Compatibility

Operating Systems

Apple IIGS ProDOS 16, GS/OS
Mac OS System 3.2 through Mac OS 9.2.2
Apple IIe Card Full compatibility
A/UX Native support
NeXT Limited compatibility

Key Mapping

Open Apple → Command
Closed Apple → Option
Delete → Backspace function
Power key Direct system control

Special Functions

Control-Open Apple-Reset System reset
Open Apple-Control-Escape Programmer's switch
Power button Cold boot from off state

Maintenance & Repair

Disassembly

Required tools

Phillips screwdriver #1
Plastic spudger
Isopropyl alcohol 90%+

Procedure

Remove three case screws (note washer presence)
Separate case halves carefully
Disconnect cable if removable
Remove PCB screws
Lift PCB assembly

Switch Cleaning

Alps switches

Remove keycap
Apply isopropyl alcohol drops
Actuate repeatedly
Allow complete drying

SMK switches

Similar process to Alps
May require disassembly for deep cleaning
Lubrication not recommended

Common Problems

**Troubleshooting Guide**
Problem	Cause	Solution
Keys not registering	Dirty switch contacts	Clean with alcohol
Repeating keys	Worn switch	Replace switch
ADB not recognized	Cable damage	Test continuity, replace
Yellowing	UV exposure, age	Retrobright treatment
Caps Lock stuck	Latch mechanism worn	Replace SKCL switch
Scratchy feel	Contamination	Disassemble and clean

Parts Availability

Alps switches Harvest from donor boards
SMK switches Unique to this model
Keycaps Not interchangeable between variants
Stabilizers Variant-specific
Cable Generic ADB cable compatible

Modern Usage

ADB to USB Adapters

Griffin iMate Original solution (discontinued)
Wombat Current best option
TMK converter DIY solution
Drakware Premium cables

Compatibility Notes

Power button may not function
All keys map correctly
No driver needed for basic function
Special keys require remapping software

Restoration

Retrobrighting

More effective on Japan variant (PBT)
Taiwan variant (ABS) prone to brittleness
Use hydrogen peroxide method
Monitor carefully to prevent damage

Switch restoration

Orange/Salmon Alps highly valued
Ultrasonic cleaning recommended
Springs can be replaced
Slider replacement difficult

Collector Information

Market Value (2024)

Japan/Orange Alps $200-400
Japan/Salmon Alps $150-300
Taiwan/SMK $100-200
Mint/boxed +100% premium

Authentication

Verify label format matches variant
Check switch type with keycap removal
Confirm keycap manufacturing method
Inspect stabilizer clip color

Desirability Factors

Orange Alps most sought after
Complete original cable important
Minimal yellowing commands premium
Original packaging extremely rare

Cultural Impact

The Apple Desktop Bus Keyboard introduced design and technical elements that influenced Apple's keyboard designs for over a decade. The dual ADB ports established the precedent for keyboard-integrated hubs, while the power button placement became standard on Apple keyboards until the early 2000s.

The keyboard's unusual layout, particularly the single-row arrow keys and unconventional modifier key positions, proved controversial. These quirks were quickly addressed in the successor M0116, demonstrating Apple's responsiveness to user feedback while maintaining design innovation.

For many users, this was their introduction to mechanical keyboards, with the Alps switches providing a typing experience that many still consider superior to modern alternatives. The keyboard's association with the Apple IIGS, used extensively in schools during the late 1980s and early 1990s, created lasting nostalgic connections for a generation of computer users.

Production Statistics

Estimated production numbers based on serial number analysis:

Total production ~750,000 units
Japan variant ~400,000 (53%)
Taiwan variant ~350,000 (47%)
Orange Alps ~200,000 units
Salmon Alps ~200,000 units
SMK switches ~350,000 units

Legacy

The Apple Desktop Bus Keyboard established several precedents:

First implementation of ADB protocol
Introduction of Snow White design language
Established dual-port keyboard design
Pioneered keyboard power button integration

While its non-standard layout was controversial, the build quality and switch technology represented a high point in Apple keyboard construction. The Orange Alps switches in particular have achieved legendary status among keyboard enthusiasts, with these switches commanding premium prices when harvested for custom keyboard projects.

The keyboard's role in introducing ADB cannot be understated—this interface would serve Apple computers for thirteen years, making it one of the longest-lived peripheral standards in personal computing history. The backward compatibility maintained throughout the ADB era meant this keyboard could be used with Macintosh systems released a decade after its discontinuation.