Editing Apple Desktop Bus Mouse (section)

== Design & Construction ==

=== Physical Characteristics ===
The ADB Mouse maintained the rectangular footprint of earlier Apple mice but featured a lower, triangular profile measuring 93mm × 61mm × 36mm. The single button spanned the entire front section of the mouse, providing a large clicking surface. The case was injection-molded ABS plastic in Apple's standard Platinum gray (Pantone 423C), with only the cable and connector retaining the darker "Smoke" gray color.

=== Internal Components ===
The mouse utilized mechanical ball tracking with the following key components:

* '''Tracking mechanism:''' 19mm rubber-coated steel ball (black on early models, gray on later)
* '''Optical encoders:''' Two perpendicular slotted wheels with infrared LED/phototransistor pairs
* '''Controller chip:''' Various manufacturers including:
** Mitsumi custom ADB controller
** Logitech 42c60p5625 (Taiwan models)
** IC Designs custom ASIC
** Alps 820-0232 (USA models)
* '''Microswitch:''' Omron D2F series rated for 1 million clicks
* '''Circuit board:''' Single-sided PCB with through-hole components

=== Manufacturing Variations ===
Five primary internal designs existed across production facilities:

'''Taiwan manufacture (Logitech):'''
* Model A9M0331 with black ball
* Beige PCB top, green bottom
* Marked "ADB Mouse by Logitech Rev C2"
* White ball cage
* Part numbers: 400115-400118

'''Taiwan manufacture (Logitech G5431):'''
* Green PCB marked "Logitech AT Rev B"
* P/N 200048-00
* Black ball cage
* Part numbers: 400234-400235

'''USA manufacture (Alps):'''
* Brown PCB stamped 820-0232
* Gray 25mm ball
* Round retainer with V-notch
* Integrated ball cage
* Part numbers: 815-1090 to 815-1092

'''USA manufacture (Unknown):'''
* Green PCB stamped 820-0146
* Gray 25mm ball
* Ribbed retainer with 3 tabs
* White ball cage
* Steel rollers

'''Malaysia manufacture (Mitsumi):'''
* Brown PCB marked Mitsumi
* Gray 25mm ball
* Black ball cage
* Two-screw PCB mounting
* Part numbers: 64-1259 to 64-1262