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Rebuild from Deskthority + Apple TIL + Guide to the Macintosh Family Hardware ch.8. Four variants are NMB Version A (4 screws) / NMB Version B (8) / Alps dome-with-slider (3) / Alps membrane dome - the claimed China variant is undocumented and removed. Deleted the under-$15 cost-reduction narrative, 200->80 part-count claim, dimensions, weight, 25/50 mA draw, environmental specs, 5-million-actuation rating, actuation forces and travels, membrane layer thicknesses, 6 MHz crystal, invented serv...
Rewrite: page said the keyboard has a single ADB port and ends the chain; Deskthority photos show a downstream ADB port. Variant table now 'case screws' per source; remove uncited claims (Chinese variant note, most common fault, enthusiast preference, no replacement wires, What Is Not Documented); ADB facts cited to Family Hardware pages; release_date param fixed
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{{Infobox computer peripheral
{{Infobox computer peripheral
| name        = AppleDesign Keyboard
| name        = AppleDesign Keyboard
| image        = [[File:AppleDesign Keyboard top.jpg|250px]]
| image        = [[File:AppleDesign Keyboard top.jpg|260px|frameless]]
| caption      = AppleDesign Keyboard M2980
| caption      = AppleDesign Keyboard M2980 (ISO layout)
| manufacturer = Apple Computer, Inc. (NMB, Alps Electric)
| manufacturer = Apple Computer, Inc. (made by NMB and Alps Electric)
| type        = Computer keyboard
| type        = Computer keyboard
| release date = 1994
| release_date = 1994
| interface    = [[Apple Desktop Bus]]
| interface    = [[Apple Desktop Bus]]
| compatible  = ADB-equipped Macintosh computers
| compatible  = ADB-equipped Macintosh computers
Line 13: Line 13:
}}
}}
<templatestyles src="Template:StyledTable/styles.css" />
<templatestyles src="Template:StyledTable/styles.css" />
The '''AppleDesign Keyboard''' (model M2980) was Apple's first low-cost full-size Macintosh keyboard — full-size meaning a function-key row and a navigation cluster.<ref name="dt">"AppleDesign Keyboard", [https://deskthority.net/wiki/AppleDesign_Keyboard Deskthority wiki]. Part number M2980; FCC ID BCGM-2980; manufacture by NMB and by Alps Electric; NMB dome-with-slider, Alps dome-with-slider and Alps membrane dome switch types; introduced 1994; supersedes the Apple Extended Keyboard II and precedes the Apple USB Keyboard; four documented variants with different keycap mounts (the keycaps are not interchangeable between them) and different numbers of rear case screws; platinum and black colours; the NMB controller ID "NMB16R2677"; NMB Version A with 1u Option keys, black barrel plate, four case screws and long wide rubber feet, and Version B with shorter keys each having a post, 1.25u Option keys, stepped Caps Lock, beige barrel plate, homing keys (D, K and numpad 5) with stems rotated 90°, eight case screws and long narrow feet; Alps dome-with-slider units from Mexico with pad-printed ABS keycaps and from the Czech Republic with dye-sublimated PBT, three rear screw holes, a thin metal plate held to the membrane assembly by melted plastic rivets, OEM-profile keycaps with a 1.5/1.25/1.5/6.5/1.5/1.25/1.5 u bottom row, an offset Caps Lock slider and stabilising wire hinged on the keys and running in recesses in the membrane assembly; and the Alps membrane-dome variant with a self-contained membrane module screwed to the base, a curved black key mounting plate taking integrated-mount keycaps, clear loose domes, dome housings identical to the Alps KFRF-1, a controller reading "©APPLE, Inc" and 39 screws securing the back of the membrane module. '''Community wiki, cited as a secondary source''', photograph-backed.</ref> It replaced the mechanical [[Apple Extended Keyboard II]] with '''rubber domes''', and was itself replaced by the Apple USB Keyboard.<ref name="dt" /> Deskthority dates its introduction to '''1994''' and gives the FCC ID as '''BCGM-2980'''.<ref name="dt" />
The '''AppleDesign Keyboard''' (model M2980) was Apple's first low-cost full-size Macintosh keyboard, full-size meaning it has a function-key row and a navigation cluster. It was introduced in 1994, uses rubber domes where the [[Apple Extended Keyboard II]] it replaced used Alps mechanical switches, and was followed by the Apple USB Keyboard. The FCC ID is BCGM-2980.<ref name="dt">Deskthority wiki, [https://deskthority.net/wiki/AppleDesign_Keyboard "AppleDesign Keyboard"]: part number M2980, FCC ID BCGM-2980, made by NMB and Alps Electric, introduced 1994; variant descriptions and photographs (NMB dome with slider versions A and B, Alps dome with slider from Mexico and the Czech Republic, Alps membrane dome); fixed cable and downstream ADB port. Community wiki, secondary source. Retrieved 2026-09-30.</ref>


Most are "platinum" beige; '''a black version was also made''', shipped with the black Macintosh models.<ref name="dt" />
Most were made in "platinum" beige; a black version was shipped with the black Macintosh models. Most have a fixed cable, which Deskthority reports is Apple's official specification; some production runs are reported to have had detachable cables and Alps-compatible sliders. The keyboard has one downstream ADB port for a mouse or other device.<ref name="dt" />


== The Four Variants ==
== Variants ==
 
There are at least four internal designs. They look alike from outside, but the keycap mount differs between them, so keycaps are not interchangeable, and the number of screw holes in the case differs.<ref name="dt" />
This is the single most useful thing to know about the M2980: there are '''at least four distinct internal designs'''. From the outside they look very similar, but '''the keycap mount differs between them and the keycaps are not interchangeable''', and the number of screw holes on the rear differs.<ref name="dt" /> Get this wrong and you will buy a donor whose keycaps do not fit yours.


{| class="wikitable styled-table" style="width:95%;"
{| class="wikitable styled-table" style="width:95%;"
|+'''Identifying the variant'''<ref name="dt" />
|+'''Identifying the variant'''<ref name="dt" />
! Variant !! Rear screws !! Domes !! Keycaps !! Other markers
! Variant !! Case screws !! Domes and switches !! Keycaps !! Other markers
|-
|-
| '''NMB dome with slider, "Version A"''' || 4 || Bright yellow || — || Option keys 1 u; '''black''' barrel plate; long, wide rubber feet; white NMB sliders; controller ID "NMB16R2677"
| NMB dome with slider, "Version A" || 4 || white NMB sliders over bright yellow domes || || Option keys 1 u; black barrel plate; long, wide rubber feet; controller marked "NMB16R2677"
|-
|-
| '''NMB dome with slider, "Version B"''' || 8 || Bright yellow || Shorter, each with a post || Option keys 1.25 u; stepped Caps Lock (1.5:0.25); '''beige''' barrel plate; homing keys (D, K, numpad 5) have stems rotated '''90°'''; long, narrow feet
| NMB dome with slider, "Version B" || 8 || white NMB sliders over bright yellow domes || shorter, each with a post || Option keys 1.25 u; stepped Caps Lock (1.5:0.25); beige barrel plate; homing keys (D, K, numpad 5) have stems rotated 90°; long, narrow feet
|-
|-
| '''Alps dome with slider''' || 3 || — || '''Mexico:''' pad-printed ABS. '''Czech Republic:''' dye-sublimated PBT || "Type 2" Alps dome-with-slider; thin metal plate held to the membrane assembly by '''melted plastic rivets'''; OEM-profile keycaps, 1.5 / 1.25 / 1.5 / 6.5 / 1.5 / 1.25 / 1.5 u bottom row; Caps Lock slider offset to line up with Tab above it
| Alps dome with slider || 3 || Alps "Type 2" dome with slider || OEM profile; Mexico: pad-printed ABS; Czech Republic: dye-sublimated PBT || thin metal plate held to the membrane assembly by melted plastic rivets; bottom row 1.5/1.25/1.5/6.5/1.5/1.25/1.5 u; Caps Lock slider offset to line up with Tab
|-
|-
| '''Alps membrane dome''' || — || '''Clear''', loose || Integrated-mount || Self-contained membrane module screwed to the base; '''curved''' black key mounting plate; dome housings identical to the Alps KFRF-1; controller reads "©APPLE, Inc"; '''39 screws''' hold the back of the membrane module
| Alps membrane dome || || clear loose domes in a self-contained membrane module; dome housings identical to the Alps KFRF-1 || integrated mount || curved black key mounting plate; controller marked "©APPLE, Inc"; 39 screws on the back of the membrane module
|}
|}


The three-screws-versus-four-or-eight distinction is the quickest external check: three rear screw holes means an Alps dome-with-slider board.<ref name="dt" />
Three screw holes on the bottom of the case identify the Alps dome-with-slider board.<ref name="dt" />
 
'''There is no documented Chinese-built variant.''' Descriptions of a fourth, generically-sourced "China production" M2980 with higher failure rates could not be corroborated against any photograph-backed source and are not reproduced here.
 
== Cable ==
 
'''Apple's official specification is a fixed cable''', and most AppleDesign Keyboards have one.<ref name="applekb">Apple Computer, Inc., "Extended Keyboard II &amp; AppleDesign Keyboard: Differences", Apple technical information library, cited via [https://deskthority.net/wiki/AppleDesign_Keyboard Deskthority]. Apple's official specification gives the AppleDesign Keyboard a fixed cable. Deskthority records reports of production runs with detachable cables and Alps-compatible sliders, from Geekhack threads, which it marks as reports rather than as documentation.</ref> Deskthority records reports of production runs with '''detachable cables and Alps-compatible sliders''', from community threads; it presents these as reports rather than as documentation, and so does this page.<ref name="applekb" />
 
A fixed cable makes strain-relief failure a soldering job rather than a swap, and it is the most common fault on a surviving example.


== Construction ==
== Construction ==
=== NMB variants ===
=== NMB variants ===
White NMB sliders over bright yellow domes, a three-layer membrane, and a controller bearing "NMB16R2677" — which is most of why the keyboard is attributed to NMB at all.<ref name="dt" /> The cable is fixed and exits through a moulded channel.<ref name="dt" />
The upper shell carries white NMB sliders over bright yellow domes. The keyboard controller is marked "NMB16R2677", which is part of the reason the keyboard is attributed to NMB. The fixed cable exits through a cable channel.<ref name="dt" /> On Version B the stems of D, K and numpad 5 are rotated 90°, so note their orientation before removing them.<ref name="dt" />
 
The '''90°-rotated stems on the homing keys''' of Version B are worth noting before reassembly: D, K and numpad 5 will not go back on in the same orientation as their neighbours.<ref name="dt" />


=== Alps dome with slider ===
=== Alps dome with slider ===
The metal plate is held to the membrane assembly by '''melted plastic rivets'''.<ref name="dt" /> That is the important detail for repair: there are no screws to undo, and separating the plate to reach the membrane means breaking the rivets. Plan for it — it is a one-way operation, and reassembly needs either adhesive or small screws through the remains.
The metal plate is fixed to the membrane assembly by melted plastic rivets, not screws, so the plate cannot be separated without cutting them. The stabiliser wires are hinged on the keys and slide in recesses in the membrane assembly.<ref name="dt" />
 
The stabilising wire is '''hinged on the keys''' and slides in '''recesses in the membrane assembly''', not in separate housings.<ref name="dt" /> Do not lose the wires; there are no replacements.
 
The Czech-built boards with '''dye-sublimated PBT keycaps''' are the ones enthusiasts look for. The Mexican-built boards have '''pad-printed ABS''', whose legends wear off.<ref name="dt" />


=== Alps membrane dome ===
=== Alps membrane dome ===
This variant is the odd one out in every respect: a '''self-contained membrane module that screws to the base''', a '''curved''' black mounting plate taking '''integrated-mount''' keycaps, and '''clear loose domes''' rather than a dome sheet.<ref name="dt" /> The dome housings are identical to those of the Alps KFRF-1.<ref name="dt" />
The self-contained membrane module screws to the base of the keyboard. It has three membrane layers, the upper one printed with Alps branding, and loose clear domes. The 39 screws on the back of the module apply the pressure that holds the membrane sheets together, so all of them need to be refitted evenly.<ref name="dt" />


'''39 screws secure the back of the membrane module''', applying the pressure that holds the membrane sheets together.<ref name="dt" /> If you open one, expect that count, keep the screws, and understand that the uniform pressure they apply is what makes the keyboard work — missing or unevenly tightened screws produce dead keys in patches.
== ADB ==
 
The M2980 is an encoded ADB device, and keyboards default to ADB address $02.<ref name="g318">Apple Computer, ''Guide to the Macintosh Family Hardware'', 2nd edition (1990), chapter 8, "Apple Desktop Bus", Table 8-16, p. 318. Hosted as [[:File:Apple Guide to the Macintosh Family Hardware 2nd Edition 1990.pdf]].</ref> All devices on one bus together may draw no more than 500 mA, cables should be no longer than 5 m, and Apple does not recommend daisy-chaining more than three devices on one ADB port.<ref name="g292">''Guide to the Macintosh Family Hardware'', 2nd ed., p. 292.</ref> Do not unplug or plug in an ADB device while the computer is running.<ref name="g287">''Guide to the Macintosh Family Hardware'', 2nd ed., p. 287.</ref> See [[Apple Desktop Bus]] for the protocol.
== ADB Behaviour ==
 
The M2980 is an ordinary ADB encoded device at default address '''$02'''.<ref name="gmfh">''Guide to the Macintosh Family Hardware'', second edition, Apple Computer, Inc. / Addison-Wesley, 1990 — hosted on this wiki as [[:File:Apple Guide to the Macintosh Family Hardware 2nd Edition 1990.pdf]]. Chapter 8, "Apple Desktop Bus": Table 8-1 connector signal assignments (470 Ω pull-up, POWER.ON on pin 2); Table 8-2 transceiver electrical characteristics; Table 8-4 register 0 in the Apple Standard Mouse and its note on 100 ±10 / 200 ±10 counts per inch; Tables 8-7 and 8-8 registers 0 and 2 in the Apple Standard Keyboard; Tables 8-10 and 8-11 registers 0 and 2 in the Apple Extended Keyboard and the $0002 → $0003 Device Handler ID change for right-hand Option and Control; Table 8-13 command byte syntax; Table 8-14 the full ADB timing specification; Table 8-15 device register 3; Table 8-16 device addresses; Table 8-17 reserved Device Handler IDs; the 500 mA total bus limit, the 5 m / 100 pF-per-metre cable limits, the 11 ms idle polling interval and the warning against unplugging a device while the computer is running. Chapter 9, "Floppy Disk Interfaces": Table 9-1 drive capacities, file systems and encoding; the IWM and SWIM interface ICs; internal 20-pin and external DB-19 pinouts; drive current requirements; and the PWM motor-speed line used only by 400K single-sided drives.</ref>
 
* '''Register 0''' carries two key events in one 16-bit read.<ref name="gmfh" />
* '''Register 2''' carries modifier-key status, with 0 meaning down.<ref name="gmfh" />
* Apple documents no polling rate; in the idle state the transceiver repeats the last Talk command '''every 11 ms'''.<ref name="gmfh" />
* All devices on the bus together must draw no more than '''500 mA''', with no more than '''three devices''' daisy-chained on one port and no more than '''5 m''' of cable.<ref name="gmfh" />
 
Unlike its mechanical predecessors this keyboard has a single ADB port, so it is the end of the chain rather than a pass-through.<ref name="dt" />
 
== Maintenance and Repair ==


== Maintenance and repair ==
=== Identify the variant first ===
=== Identify the variant first ===
Count the rear screws and look at the dome colour through a removed keycap. '''Every repair below depends on which of the four you have''', and keycaps and membranes do not swap between them.<ref name="dt" />
Count the screws in the bottom of the case and look at the dome colour under a removed keycap. Keycaps and membranes do not swap between the variants.<ref name="dt" />


=== Dead key or dead patch ===
=== Dead key or dead patch ===
# On the Alps membrane-dome variant, check the '''39 module screws''' before anything else — the module relies on even pressure across the membrane sheets.<ref name="dt" />
# On the Alps membrane-dome variant, check that all 39 module screws are present and evenly tight.<ref name="dt" />
# Otherwise open the keyboard and test the membrane traces from the key pad to the tail connector with a meter on continuity.
# Open the keyboard and check the membrane traces from the key pad to the tail connector for continuity.
# A broken trace can be bridged with silver conductive paint. Clean the area with isopropyl alcohol, let it dry fully, build the bridge in thin coats and test resistance before reassembly.
# A broken trace can be bridged with conductive silver paint. Clean the area with isopropyl alcohol, let it dry, build the bridge in thin coats and check its resistance before reassembly.
# A whole dead row or column is a matrix line, not individual keys — follow it back to the tail connector, where a partly-seated or corroded connection is the usual cause.
# A whole dead row or column is a matrix line: follow it back to the tail connector and check the connection there.
 
=== Cable failure at the case ===
The fixed cable is the commonest fault.<ref name="applekb" /> Test each conductor for continuity while flexing at the entry point. A splice with heat-shrink and a fresh strain relief restores it; the alternative is desoldering the cable at the PCB and fitting a new four-conductor lead, keeping the pinout.
 
=== Liquid ingress ===
Full disassembly, rinse the membrane in distilled water, then isopropyl alcohol, then dry thoroughly before testing. Inspect for corrosion on the tail connector contacts, which is where the damage usually persists.
 
=== Mushy or stiff keys ===
Hardened or torn domes. On the Alps membrane-dome variant the domes are '''loose''' and can be replaced individually; on the others they are part of a sheet and cannot.<ref name="dt" />


=== Keycaps will not fit ===
=== Cable fault ===
That is the variant problem, not a fault. '''Keycaps are not interchangeable between the four designs.'''<ref name="dt" />
The cable is fixed on most examples.<ref name="dt" /> Check each conductor for continuity while flexing the cable at the case entry. Repair with a splice and heat-shrink and a new strain relief, or replace the cable at the PCB keeping the same pinout.


== What Is Not Documented ==
=== Soft or sticking keys ===
Worn or torn domes. On the Alps membrane-dome variant the domes are loose and can be replaced individually.<ref name="dt" />


No Apple figures for dimensions, weight, retail price, key durability, power consumption, operating environment or production volumes for the M2980 could be traced, and none are stated here. Nor could any source be found for rated dome lifetimes, membrane service life or a failure-progression timetable; such figures circulate widely and are invented. '''Do not replace parts of this keyboard on a schedule''' — replace them when they fail.
== See also ==
 
== Restoration ==
 
The case is ABS and yellows. Pad-printed legends on the Mexican-built Alps boards will not survive aggressive cleaning; dye-sublimated PBT legends will. See [[Retrobrite]] before treating a case.
 
== See Also ==
* [[Apple Extended Keyboard II]]
* [[Apple Extended Keyboard II]]
* [[Apple Adjustable Keyboard]]
* [[Apple Desktop Bus]]
* [[Apple Desktop Bus]]
* [[Retrobrite]]


== References ==
== References ==
<references />
<references />


Revision as of 13:19, 30 September 2026

AppleDesign Keyboard
AppleDesign Keyboard M2980 (ISO layout)
Manufacturer Apple Computer, Inc. (made by NMB and Alps Electric)
Type Computer keyboard
Release date 1994
Interface Apple Desktop Bus
Compatible ADB-equipped Macintosh computers
Predecessor Apple Extended Keyboard II
Successor Apple USB Keyboard
Model M2980

The AppleDesign Keyboard (model M2980) was Apple's first low-cost full-size Macintosh keyboard, full-size meaning it has a function-key row and a navigation cluster. It was introduced in 1994, uses rubber domes where the Apple Extended Keyboard II it replaced used Alps mechanical switches, and was followed by the Apple USB Keyboard. The FCC ID is BCGM-2980.[1]

Most were made in "platinum" beige; a black version was shipped with the black Macintosh models. Most have a fixed cable, which Deskthority reports is Apple's official specification; some production runs are reported to have had detachable cables and Alps-compatible sliders. The keyboard has one downstream ADB port for a mouse or other device.[1]

Variants

There are at least four internal designs. They look alike from outside, but the keycap mount differs between them, so keycaps are not interchangeable, and the number of screw holes in the case differs.[1]

Identifying the variant[1]
Variant Case screws Domes and switches Keycaps Other markers
NMB dome with slider, "Version A" 4 white NMB sliders over bright yellow domes Option keys 1 u; black barrel plate; long, wide rubber feet; controller marked "NMB16R2677"
NMB dome with slider, "Version B" 8 white NMB sliders over bright yellow domes shorter, each with a post Option keys 1.25 u; stepped Caps Lock (1.5:0.25); beige barrel plate; homing keys (D, K, numpad 5) have stems rotated 90°; long, narrow feet
Alps dome with slider 3 Alps "Type 2" dome with slider OEM profile; Mexico: pad-printed ABS; Czech Republic: dye-sublimated PBT thin metal plate held to the membrane assembly by melted plastic rivets; bottom row 1.5/1.25/1.5/6.5/1.5/1.25/1.5 u; Caps Lock slider offset to line up with Tab
Alps membrane dome clear loose domes in a self-contained membrane module; dome housings identical to the Alps KFRF-1 integrated mount curved black key mounting plate; controller marked "©APPLE, Inc"; 39 screws on the back of the membrane module

Three screw holes on the bottom of the case identify the Alps dome-with-slider board.[1]

Construction

NMB variants

The upper shell carries white NMB sliders over bright yellow domes. The keyboard controller is marked "NMB16R2677", which is part of the reason the keyboard is attributed to NMB. The fixed cable exits through a cable channel.[1] On Version B the stems of D, K and numpad 5 are rotated 90°, so note their orientation before removing them.[1]

Alps dome with slider

The metal plate is fixed to the membrane assembly by melted plastic rivets, not screws, so the plate cannot be separated without cutting them. The stabiliser wires are hinged on the keys and slide in recesses in the membrane assembly.[1]

Alps membrane dome

The self-contained membrane module screws to the base of the keyboard. It has three membrane layers, the upper one printed with Alps branding, and loose clear domes. The 39 screws on the back of the module apply the pressure that holds the membrane sheets together, so all of them need to be refitted evenly.[1]

ADB

The M2980 is an encoded ADB device, and keyboards default to ADB address $02.[2] All devices on one bus together may draw no more than 500 mA, cables should be no longer than 5 m, and Apple does not recommend daisy-chaining more than three devices on one ADB port.[3] Do not unplug or plug in an ADB device while the computer is running.[4] See Apple Desktop Bus for the protocol.

Maintenance and repair

Identify the variant first

Count the screws in the bottom of the case and look at the dome colour under a removed keycap. Keycaps and membranes do not swap between the variants.[1]

Dead key or dead patch

  1. On the Alps membrane-dome variant, check that all 39 module screws are present and evenly tight.[1]
  2. Open the keyboard and check the membrane traces from the key pad to the tail connector for continuity.
  3. A broken trace can be bridged with conductive silver paint. Clean the area with isopropyl alcohol, let it dry, build the bridge in thin coats and check its resistance before reassembly.
  4. A whole dead row or column is a matrix line: follow it back to the tail connector and check the connection there.

Cable fault

The cable is fixed on most examples.[1] Check each conductor for continuity while flexing the cable at the case entry. Repair with a splice and heat-shrink and a new strain relief, or replace the cable at the PCB keeping the same pinout.

Soft or sticking keys

Worn or torn domes. On the Alps membrane-dome variant the domes are loose and can be replaced individually.[1]

See also

References

  1. ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 Deskthority wiki, "AppleDesign Keyboard": part number M2980, FCC ID BCGM-2980, made by NMB and Alps Electric, introduced 1994; variant descriptions and photographs (NMB dome with slider versions A and B, Alps dome with slider from Mexico and the Czech Republic, Alps membrane dome); fixed cable and downstream ADB port. Community wiki, secondary source. Retrieved 2026-09-30.
  2. ↑ Apple Computer, Guide to the Macintosh Family Hardware, 2nd edition (1990), chapter 8, "Apple Desktop Bus", Table 8-16, p. 318. Hosted as File:Apple Guide to the Macintosh Family Hardware 2nd Edition 1990.pdf.
  3. ↑ Guide to the Macintosh Family Hardware, 2nd ed., p. 292.
  4. ↑ Guide to the Macintosh Family Hardware, 2nd ed., p. 287.


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