Apple Aluminium Keyboard

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Apple Aluminium Keyboard
Apple Wired Aluminium.jpg
Part number Various
Branding Apple
Keyswitches Scissor switch
Keycaps Laser-etched chiclet
Interface USB, Bluetooth

This page is about contemporary Apple keyboards with chiclet keys and an aluminium enclosure.

"Apple Keyboard"

USB keyboards with one downstream USB port on each side (two in total).

A1243 MB110B/A

Full size keyboard.

A1242 MB110B/B

Compact version without numeric keypad and navigation keys. Cursor keys have been moved into a space below the right shift key.

Shipped with 2009 iMac. Discontinued in 2010.


"Apple Wireless Keyboard"

Layout is reminiscent of the compact A1242. The keyboard communicates through Bluetooth. It works also with iOS devices.

A1255

Takes three AA batteries.

A1314 MC184LL/A

Takes only two AA batteries.

A1314 MC184LL/B

Compared to MC184LL/A, the keyboard has keys for Launchpad and Mission Control where the keys for Exposé and Dashboard used to be.

Succeeded by the Apple Magic Keyboard with new Macintosh models, but is still available to buy separately (July 2016).

Layout

The keyboard has chiclet keys.

While each normal key is a standard 3/4 inch (19 mm) on the horizontal, it is smaller than standard on the vertical.

The Fn key is located on the bottom left on small keyboards and above forward delete in the nav cluster on "full-size" keyboards.

There are several media key functions overlaid on the function keys. Whether these require the Fn key, or the opposite is a configurable option on the host side. This configurability requires MacOS or a special driver on Windows.

F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12
Brightness Down Brightness Up Exposé / Mission Control Dashboard / Launchpad Rewind (Previous track) Play/Pause Fast Forward (Next track) Mute Volume Down Volume Up

Protocol

Beside media key reports, the USB HID protocol format is the standard boot protocol except that it is only 5KRO to give room for reporting the Fn key in the last byte. A USB host that ignores the keyboard's "Report Descriptor" (such as many PC BIOS:es) will see the keyboard reporting the Fn key as an "Undefined key".

Bluetooth keyboards talk the same HID protocol as USB, just over Bluetooth's transport rather than over USB's transport layer.

Construction

From the bottom up, the keyboard is made of these layers:

  1. ABS bottom plate.
  2. A layer of glue. The glue can be dissolved with isopropyl alcohol.
  3. Thin steel plate.
  4. The switch membrane. Three sublayers.
  5. Rubber domes installed on a thin, flexible, non-elastic plastic sheet.
  6. Upper aluminium case. Holes for keycaps.

The bottom plate is glued to the steel plate with a considerable amount of glue. There are screws and/or bolts the steel plate to the aluminium enclosure.

The scissor mechanism for a key fits between the keycaps and layer 5. The lower hinges of the scissors go through holes in layers 5 and 4, latch on behind shaped protrusions of the steel plate and end up touching the glue layer.[1]

The aluminium enclosure is made from a block of T6/6061 aluminium that has been milled, bead-blasted and anodized grey (without dye). Some (if not all) keyboards have been constructed from blocks that have been cut out when milling larger blocks to become iMac enclosures. Two full-size keyboards can be made for one iMac from the same block of metal.

References

  1. Geekhack user hemflit, [Disassembling an Apple Wireless]. Article on Geekhack.org's forum.