Model M keyboard
Model M designates a group of computer keyboards designed and manufactured by IBM starting in 1984, and later by Lexmark International, Maxi Switch, and Unicomp. The keyboard's many variations have their own distinct characteristics, with the vast majority having a buckling-spring key design and swappable keycaps. Model M keyboards have been praised by computer enthusiasts and frequent typists due to their durability and consistency, and the tactile and auditory feedback they provide.
The Model M is also regarded as a timeless and durable piece of hardware. Although the computers and computer peripherals produced concurrently with the Model M are considered obsolete, many Model M keyboards are still in use due to their physical durability and the continued validity of their ANSI 101-key and ISO 102-key layouts, through the use of a PS/2 female to USB male adapter with a built-in level converter. Since their original popularity, new generations of writers and computer technicians have rediscovered their unique functionality and aesthetics. The Kentucky-based company Unicomp continues to manufacture and sell Model M keyboards.
History
The Model M keyboard was designed to be more cost effective than the Model F keyboard it replaced. Production of model M keyboards began in 1985, and they were often bundled with new IBM computers. They were produced at IBM plants in Lexington, Kentucky, Greenock, Scotland, and Guadalajara, Mexico. The most common variant is the IBM Enhanced Keyboard identified by IBM assembly part number 1391401, the U.S. English layout keyboard bundled with the IBM Personal System/2. Until around 1993, most Model Ms included a sturdy, coiled, detachable cable, with either an AT or PS/2 connector, in 5- and 10-foot lengths. From about 1994 onwards, flat non-detachable cables were used to reduce manufacturing costs; however, IBM retained its 101-key layout, never implementing the Microsoft Windows keys common on other keyboards from that time. Unicomp later designed a 104-key Model M with Windows keys.On March 27, 1991, IBM divested a number of its hardware manufacturing operations, including keyboard production, forming Lexmark International. Lexmark continued manufacturing model M keyboards in the United States, United Kingdom, and Mexico, with IBM being Lexmark's major customer. Many of these keyboards are identified by IBM assembly part numbers 52G9658, 52G9700, 71G4644, 82G2383, and 42H1292, which were bundled with IBM PS/ValuePoint and IBM PC Series. Because of pricing pressures, these keyboards were manufactured with a new, lower-cost design, including lighter plastic, an integrated cable, and a single color for key legends.
A five-year agreement obligating IBM to purchase nearly all of its keyboards from Lexmark expired on March 27, 1996. Lexmark exited the keyboard business, selling related assets to IBM and Maxi Switch. When Lexmark discontinued keyboard production in April 1996, IBM continued producing buckling-spring model M keyboards in Scotland until 1999. Maxi Switch purchased assets for rubber-dome keyboards and the Lexmark Select-Ease Keyboard, including a buckling-spring switch patent. Maxi Switch continued to manufacture the IBM Enhanced Keyboard with TrackPoint II in Mexico until 1998. Some of Lexmark's keyboard manufacturing assets were also sold to a group of Lexmark employees, who formed Unicomp. Unicomp still manufactures its version of the Model M, as well as other configurations including updated 104- and 105-key layouts; a Unix layout ; models with integrated pointing sticks or trackballs; and POS-specific models such as those with built-in magstripe readers. Although current Unicomp models may still be purchased, original production models retain their value well among collectors and computer enthusiasts.
Variations
The Model M's numerous variations incorporated alternative features and/or colors. One of the most popular variants is the Space Saving Keyboard, which integrates the number pad into the keyboard's main section, substantially reducing its width.IBM released the standard and Space Saving Model M's in an alternative 'gray/pebble' colour for use with their Industrial computers; this darker color was designed to conceal discoloration from handling in production environments. Other variable features include a grounded spacebar and, on some later models, drainage holes to deter damage from spilled drinks.
Design
The variant most commonly referred to as "Model M" is Part No. 1391401, on which many other variants were based. This model, known as the Enhanced Keyboard, included IBM's patented buckling spring design and swappable keycaps.The Model M's design has been widely praised as durable and reliable, and has remained basically the same since the 1980s, while virtually all other computing hardware, from PCs to monitors to mice, has changed dramatically. The M's sturdy design, including its heavy steel backplate and strong plastic frame, has allowed even the most abused examples to survive for years.
The Model M's buckling spring key design gives it a unique feel and sound. Unlike more common and cheaper dome switch designs, buckling springs give users unmistakable tactile and auditory feedback. Because of its more defined touch, some users report they can type faster and more accurately on the Model M than on other keyboards.
The Model M is also less susceptible to dirt and wear. Dirt can interfere with the proper operation of most other keyboard technologies; however, the buckling spring switch's design is such that any dirt that falls between the keys is unlikely to enter the switch mechanism, which is covered by the key. Even if dirt were to enter a mechanism, a large amount would be necessary to prevent it from operating.
Until the late 4th-generation variants, most Model M's have a 1.25" slotted, circular speaker grille in their bottom surfaces. Relatively few contain an actual speaker, however, which was useful only for sounding beep codes on older terminal systems. The most common p/n's with speakers are 1394540 and 51G872, made for RS/6000 UNIX workstations.
There are some drawbacks to the Model M design:
- Because they are so large and heavy they are not as portable as more modern keyboards.
- Their buckling-spring keys are noisy enough to be inappropriate in quiet locations such as libraries and medical facilities.
- Liquids spilled on most Model M's do not drain out, and remain in the keyboard with potential to cause a short circuit. The later 42H1292 and 59G780 designs, as well as post-1993 1370477s and 1391401s made mostly by Lexmark and Unicomp, have drainage channels designed to avoid this problem.
- Unicomp currently produces Model M's with USB connectors that can be connected directly to modern PCs. However, earlier Model M's have either AT or PS/2 connectors, requiring adapters for PCs lacking those capabilities. Some PS/2-to-USB adapters are unreliable with early Model M's that require more power than the adapters can provide.
Identification
Features by part number
Logo position legend:- LC - Left Corner
- RC - Right Corner
- LLC - Lower Left Corner
- LRC - Lower Right Corner
- ULC - Upper Left Corner
- URC - Upper Right Corner
- LLP - Lock-Light Panel
| Part number | Switch type | Detachable keycaps | Detachable cable | Interf. | Drainage channels | Logo type, position | Maker | Years | Copyright | Features | - | - | - | - | - | - | - | - | - | - | - |
| Part number | Switch type | Detachable keycaps | Detachable cable | Interf. | Drainage channels | Logo type, position | Maker | Years | Copyright | Features | 02K3760 | Buckling spring | PS/2 | None | Unicomp | ?-2005-? | None | Unicomp-made IBM keyboard | |||
| 02K3817 | Buckling spring | PS/2 | None | Unicomp | Unicomp, Inc. 1984 | German QWERTZ layout | - | - | - | - | - | - | - | - | - | - | - | ||||
| 06H4173 | Buckling spring | PS/2 | Silver on black oval, ULC Blue on white oval, ULC | Maxi Switch, Unicomp | 1997-99 | Unicomp, Inc. 1984, or none | Dark gray Industrial PS/2 trackpoint w/two connectors for keyboard and mouse | - | - | - | - | - | - | - | - | - | - | - | |||
| 1369050 | Buckling spring | PS/2 | Gray DELL logo, ULC | Lexmark "Made in the USA" | ?-1994-95-? | Lexmark International, Inc. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 1370475 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | 1993-? | Lexmark International, Inc. 1984 | Space Saving Keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 1370477 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | 1993-96 | Lexmark International, Inc. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 1370478 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | 1993 | Lexmark Int'l. Inc. 1984 | Model M5 w/miniature trackball and L/R "click" and "drag" buttons btw. navigation keys | - | - | - | - | - | - | - | - | - | - | - | |||
| 1378160 1378162 | Buckling spring | PS/2 | AMBRA logo on raised trapezoid, ULC None | Lexmark | 1993-94 | Lexmark Int'l, Inc. 1984 | Same p/n's used for two sub-variants: IBM AMBRA budget home PCs Logoless OEM boards | - | - | - | - | - | - | - | - | - | - | - | |||
| 1378186 | Rubber dome | PS/2 | Lexmark logo, ULC | Lexmark | ?-1994-? | Lexmark International, Inc. 1985 | Only known rubber-dome Model M sold under Lexmark's name | - | - | - | - | - | - | - | - | - | - | - | |||
| 1378192 | Buckling spring | PS/2 | Lexmark logo, ULC | Lexmark | ?-1994-? | Lexmark Int'l. Inc. 1984 | White Model M13 with Trackpoint II | - | - | - | - | - | - | - | - | - | - | - | |||
| 1378210 | Buckling spring | PS/2 | None | Lexmark | ?-1995-? | Lexmark Int'l. Inc. 1984 | Model M5-2 w/trackball, L/R "click" and "drag" buttons above LLP | - | - | - | - | - | - | - | - | - | - | - | |||
| 1386303 | Buckling spring | Terminal DIN-5 | Square metal, black on silver, URC | IBM | 1985-1987-? | IBM Corp. 1984 | 102-key 3161 terminal keyboard; no lock lights | - | - | - | - | - | - | - | - | - | - | - | |||
| 1386304 | Buckling spring | AT | Square metal, black on silver, URC | IBM | ?-1985-? | IBM Corp. 1984 | No lock lights | - | - | - | - | - | - | - | - | - | - | - | |||
| 1386716 | Buckling spring | AT or PS/2 | Square metal, black on silver, URC or Gray on oval, ULC | IBM UK | ?-1986-87-? | IBM Corp. 1986; IBM Corp. 1987 | German QWERTZ layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1386887 | Buckling spring | Terminal DIN-5 | Black on square silver metal, URC | IBM | ?-1986-? | IBM Corp. 1985 | 122-key 3179 terminal keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 1388032 | Buckling spring | AT | Silver on square black metal, URC | IBM | 1985, 1986 | IBM Corp. 1984 | Dark grey industrial version | - | - | - | - | - | - | - | - | - | - | - | |||
| 1389194 | Buckling spring | Terminal DIN-5 | Black on square silver metal, URC | IBM | ?-1986-? | IBM Corp. 1984 | 122-key 3179/3192 terminal keyboard with APL keycaps | - | - | - | - | - | - | - | - | - | - | - | |||
| 1389969 | Buckling spring | XT, AT | Black on square silver metal, URC | IBM UK | 1986 | IBM Corp. 1984 | UK layout; no lock lights | - | - | - | - | - | - | - | - | - | - | - | |||
| 1389979 | Buckling spring | AT | Black on square silver metal, URC | IBM | 1986-87 | IBM Corp. 1984 | Swedish layout; no lock lights | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390120 | Buckling spring | XT, AT | Black on square silver metal, URC | IBM | 1986-87 | IBM Corp. 1984 | No lock lights | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390131 | Buckling spring | AT or PS/2 | Black on square silver metal, URC | IBM | 1986–88, 1992–93 | IBM Corp. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 1390132 | Buckling spring | AT or PS/2 | Black on square silver metal, URC | IBM | 1986-? | IBM Corp. 1986 | French AZERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390133 | Buckling spring | AT or PS/2 | Black on square silver metal, URC | IBM | ?-1986-87 | IBM Corp. 1984 | German QWERTZ layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390136 | Buckling spring | AT or PS/2 | Black on square silver metal, URC | IBM | ?-1986-87 | IBM Corp. 1984 | UK layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390137 | Buckling spring | PS/2 | Black on square silver metal, URC | IBM | ?-1987-? | IBM Corp. 1984 | UK layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390148 | Buckling spring | XT | Black on square silver metal, URC | IBM | ?-1986-87 | IBM Corp. 1984 | German QWERTZ layout; no lock lights | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390572 | Buckling spring | Terminal DIN-5 | Black on square silver metal, URC | IBM | 1986-1987? | IBM Corp. 1985 | 122-key terminal keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390639 | Buckling spring | XT | Black on square silver metal, URC | IBM | ?-1987-? | IBM Corp. 1985 | Spanish QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390653 | Buckling spring | AT | Silver on square black metal, URC | IBM | 1988 | IBM Corp. 1985 | Dark gray Industrial version | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390670 | Buckling spring | Terminal DIN-5 | Black on square silver metal, URC | IBM | 1987 | IBM Corp. 1985 | Terminal keyboard that shipped with the IBM 3162 | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391240 | Buckling spring | PS/2 | Black on square silver metal, URC, w/small T in LRC | IBM | 1987-? | IBM Corp. 1984 | Esc key says Esc Reset | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391401 | Buckling spring | AT or PS/2 | Grey on oval, ULC | IBM | 1986-96 | IBM Corp. 1984 | Standard variant on which most 2nd-generation Model M's are based | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391402 | Buckling spring | PS/2 | ? | Grey on oval, ULC | IBM UK | 1990-96-? | IBM Corp. 1985 | French AZERTY layout | - | - | - | - | - | - | - | - | - | - | - | ||
| 1391403 | Buckling spring | AT or PS/2 | Gray or blue on oval, ULC | IBM UK, Lexmark International | 1986-97 | IBM Corp./Lexmark International Inc. 1985 | German QWERTZ layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391404 | Buckling spring | AT or PS/2 | Gray on oval, ULC | IBM UK | 1986-? | IBM Corporation | Italian QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391405 | Buckling spring | AT or PS/2 | Gray or blue on oval, ULC | IBM UK | 1986-? | IBM Corp. 1985 | Spanish QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391406 | Buckling spring | AT or PS/2 | Gray or blue on oval, ULC | IBM | =1985–99 | IBM United Kingdom | UK 102-key | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391407 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM | ?94-95-96-? | IBM United Kingdom | Danish/Icelandic 102-key | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391408 | Buckling spring | PS/2 | Blue on oval, ULC | IBM | ?-1993-? | IBM Corp. 1985 | Hebrew 101-key | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391409 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM | 1987?-94? | IBM Corp. 1985/Lexmark Int. 1985 | Norwegian 102-key | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391410 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM UK | 1989?-1992-? | IBM Corp. 1985 | Portuguese 102-key | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391411 | Buckling spring | AT or PS/2 | Gray or blue on oval, ULC | IBM UK | ?-1987-97-? | IBM Corp. 1985 | Swedish 102-key | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391412 | Buckling spring | PS/2 | Gray on oval, ULC | IBM UK | 1987-96 | IBM Corp. | Swiss French/German QWERTZ layout, 102-key | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391413 | Buckling spring | PS/2 | Gray on oval, ULC | IBM de Mexico | ?-1989-? | IBM Corp. 1984 | Spanish 102-key | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391414 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM UK | ?-1996-? | IBM Corp. 1985 | Belgian AZERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391472 | Buckling spring | AT or PS/2 | Gray on oval, ULC | IBM | 1987-91 | IBM Corp. 1984 | Space Saving Keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391490 | Buckling spring | PS/2 | Gray on oval, ULC | IBM UK | ?-1988-? | IBM Corporation | Arabic layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391506 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM de Mexico | 1990 | IBM Corp. 1984 | Spanish QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391511 | Buckling spring | PS/2 | Blue on oval, ULC | IBM UK | 1987-93 | IBM Corp. 1985 | Dutch 102-key | - | - | - | - | - | - | - | - | - | - | - | |||
| 1391580 | Buckling spring | PS/2 | Gray on oval, ULC | IBM | 1987-88 | IBM Corp. 1984 | For PC-based IBM 3270 emulation | - | - | - | - | - | - | - | - | - | - | - | |||
| 1392366 | Buckling spring | 6-pin AMP | Square metal, black on silver, URC | IBM | 1986-89 | IBM Corp. 1985 | For PC RT 6150 UNIX workstation, w/internal speaker for system "beeps". R Ctrl key says Action; number-pad "Enter" includes arrow. | - | - | - | - | - | - | - | - | - | - | - | |||
| 1392464 | Buckling spring | PS/2 | Gray on oval, ULC | IBM | 1987 | IBM Corp. 1984 | Space Saving Keyboard with special legends for IBM Displaywriter system, stepped modifier caps | - | - | - | - | - | - | - | - | - | - | - | |||
| 1392565 | Buckling spring | 8P5C | Gray on oval, ULC | Lexmark | ?-1995 | Lexmark International, Inc. 1984 | Keyboard for terminals such as IBM 3151; graphics characters on numeric keypad; Page Up/Page Down replaced with Clear/Erase EOF; bottom row: Ctrl, Reset, , Ctrl, Send | - | - | - | - | - | - | - | - | - | - | - | |||
| 1392934 | Buckling spring | AT or PS/2 | Gray or blue on oval, ULC | IBM | ?-1987-92-? | IBM Corp. 1984 | Space Saving Keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 1392980 | Buckling spring | 8P5C | Gray on oval, ULC | IBM | 1987-? | IBM Corp. 1984 | Terminal version Space Saving Keyboard ; extra front-printed legends on F-keys, nav. keys | - | - | - | - | - | - | - | - | - | - | - | |||
| 1393387 | Buckling spring | PS/2 | Gray on oval, ULC | IBM | 1990–93 | IBM Corporation 1985 | 18-key keypad for IBM Screen Reader/DOS voice-output application | - | - | - | - | - | - | - | - | - | - | - | |||
| 1393395 | Buckling spring | PS/2 | Gray on oval, ULC | IBM UK | 1985-? | IBM Corporation 1985 | Italian QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1393464 | Buckling spring | PS/2 | Gray on oval, ULC; some have red Sabre logo instead | IBM | ?-1989-92-? | IBM Corp. 1984 | Special secondary legends for Sabre airline reservation system | - | - | - | - | - | - | - | - | - | - | - | |||
| 1393669 | Buckling spring | AT or PS/2 | Gray or blue on oval, ULC; or blue below LLP | Lexmark UK, IBM UK / Unicomp | 198?-200? | Lexmark International Inc. 1985 / IBM Corp. 1985 / Unicomp 1996 | Slovenian/Croatian QWERTZ layout; with or without speaker grille | - | - | - | - | - | - | - | - | - | - | - | |||
| 1393691 | Buckling spring | AT or PS/2 | Gray on oval, ULC | IBM | ?-1988-? | IBM Corp. 1984 | Space Saving Keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 1393915 | Buckling spring? | PS/2 | Gray on oval, ULC | IBM | 198?-19?? | IBM Corp. 1984 | 49-key layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1394064 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM, Lexmark | ?-1989-90-? ?-1996-? | IBM Corp. 1984; Lexmark International, Inc. 1984 | Some front-printed secondary legends in red and green; Esc key says Escpe; red-printed Ctrl keys | - | - | - | - | - | - | - | - | - | - | - | |||
| 1394540 | Buckling spring | PS/2 | Gray on oval, ULC | IBM | 1990-92 | IBM Corp. 1984 | Made for IBM RS/6000 system, w/internal speaker for system "beeps". R Ctrl key says Ctrl/Act | - | - | - | - | - | - | - | - | - | - | - | |||
| 1394542 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM UK, Lexmark UK | 1991-95? | IBM Corp. 1985; Lexmark International, Inc. 1985 | German QWERTZ layout; made for IBM RS/6000 system, w/internal speaker for system "beeps" | - | - | - | - | - | - | - | - | - | - | - | |||
| 1394545 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM UK, Lexmark | 1990-96? | IBM Corp. 1985 / Lexmark International Inc. 1985 | Swedish/Finnish 102-key QWERTY layout; made for IBM RS/6000 system, w/internal speaker for system "beeps" | - | - | - | - | - | - | - | - | - | - | - | |||
| 1394618 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM, Lexmark | 1989-? ; ?-1994-? | IBM Corp. 1984 / Lexmark International Inc. 1985 | For IBM Personal Typing System, a PS/2 Model 30 PC for word processing. Special keycaps with green secondary w.p. commands, front-printed F-keys with commands on top. | - | - | - | - | - | - | - | - | - | - | - | |||
| 1394946 | Buckling spring | AT or PS/2 | Silver on black oval, ULC | IBM | 1988-96 | IBM Corp. 1984 | Most common Industrial Model M. ASCII & ISO versions use same p/n. | - | - | - | - | - | - | - | - | - | - | - | |||
| 1394957 | Buckling spring | PS/2 | Blue on oval, ULC | IBM UK | 1985-? | IBM Corp. 1985 | Italian QWERTY, dark gray Industrial version | - | - | - | - | - | - | - | - | - | - | - | |||
| 1394958 | Buckling spring | PS/2 | Silver on black oval, ULC | IBM UK | ?-1998-? | IBM Corp. 1985 | German QWERTZ, dark gray Industrial version | - | - | - | - | - | - | - | - | - | - | - | |||
| 1394966 | Buckling spring | PS/2 | Silver on black oval, ULC | IBM UK | 1992 | IBM Corp. 1985 | Swedish 102-key, dark gray Industrial version | - | - | - | - | - | - | - | - | - | - | - | |||
| 1395100 | Buckling spring | PS/2 | Blue on oval, ULC ; square Reply logo, URC | IBM, Lexmark | 1991-92 | IBM Corp. 1984; Lexmark International, Inc. 1984 | This p/n used for: • IBM Space Saving Keyboard • Lexmark 101-key OEM board for Reply court reporting systems | - | - | - | - | - | - | - | - | - | - | - | |||
| 1395217 | Buckling spring | AT or PS/2 | Gray on oval, ULC | IBM | ?-1989-? | IBM Corp. 1984 | Space Saving Keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 1395300 | Buckling spring | PS/2 | Blue on square, URC | IBM | 1990-93 | IBM Corp. 1984 | Model M2; shipped with IBM PS/1 PC | - | - | - | - | - | - | - | - | - | - | - | |||
| 1395674 | Buckling spring | PS/2 | Gray on oval, ULC | IBM, Lexmark | 1991-94 ; 1995 | IBM Corp. 1984; Lexmark International, Inc. 1984 | 101-key terminal emulator | - | - | - | - | - | - | - | - | - | - | - | |||
| 1395682 | Buckling spring | PS/2 | Silver on black oval, ULC | IBM | 1993-1994 | IBM Corp. 1984 | Dark gray Industrial Space Saving Keyboard ; blue keys for F1-F2, terminal paging and cursor movement | - | - | - | - | - | - | - | - | - | - | - | |||
| 1396790 | Buckling spring | PS/2 | Gray, or blue on oval, ULC | IBM | ?-1991-95? | IBM Corp. 1985 | Made in UK by IBM; North American layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1397000 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | Lexmark International, Inc. 1984 | 122-key terminal emulation keyboard: Home/Rule key with arrow keys in a "plus" layout; 24 function keys; 10-key left cluster with terminal commands | - | - | - | - | - | - | - | - | - | - | - | ||||
| 1397771 | Buckling spring | PS/2 | CompuAdd, URC | Lexmark | 1993 | Lexmark International, Inc. 1984 | For OEM CompuAdd PCs; only Model M made with large L-shaped Enter and 1u Backspace | - | - | - | - | - | - | - | - | - | - | - | |||
| 1397961 | Buckling spring | PS/2 | Lexmark logo, ULC | Lexmark | ?–1994 | Lexmark International, Inc. 1984 | Space Saving Keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 1397003 | Buckling spring | PS/2 | Blue on oval, ULC | IBM | ?-1993-99? | IBM Corp. 1985 | German QWERTZ layout; 122-key terminal made in UK by IBM | - | - | - | - | - | - | - | - | - | - | - | |||
| 1397135 | Buckling spring | PS/2 | - | Lexmark | 1995 | - | Extra legends for WordPerfect word-processing program | - | - | - | - | - | - | - | - | - | - | - | |||
| 1397599 | Buckling spring | PS/2 | Gray, or blue on oval, ULC | IBM | 1991-1995 | IBM Corp. 1984 | Similar to 1391401 w/metal stabilizer bars on number pad + and Enter keys | - | - | - | - | - | - | - | - | - | - | - | |||
| 1397651 | Buckling spring | PS/2 | Gray DELL logo, ULC | Lexmark | 1991–92 | Lexmark International, Inc. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 1397661 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM | ?-1992-94-? | IBM Corp. 1984 | 1391401-based variant, usually has one-piece buttons. | - | - | - | - | - | - | - | - | - | - | - | |||
| 1397681 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM | ?-1991-93-? | IBM Corp. 1984 | Space Saving Keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 1397721 | Buckling spring | PS/2 | Gray WANG logo, ULC | IBM | 1991-92 | IBM Corp. 1984 | Produced during IBM/WANG partnership; most presumed destroyed | - | - | - | - | - | - | - | - | - | - | - | |||
| 1397735 | Buckling spring | PS/2 | None | IBM | ?-1992-? | IBM Corp. 1984 | US 101-key; only IBM-made M variant without logo | - | - | - | - | - | - | - | - | - | - | - | |||
| 1398600 1398601 | Buckling spring | AT or PS/2 | Lexmark logo, ULC | Lexmark | ?-1992-94-? | Lexmark Int'l Inc 1984 | Only std. Model M's sold under Lexmark name | - | - | - | - | - | - | - | - | - | - | - | |||
| 1398609 | Buckling spring | PS/2 | - | Lexmark | ?-1992-? | Lexmark Int'l Inc 1984 | No logo indentation; apparently for OEMs to add logo stickers | - | - | - | - | - | - | - | - | - | - | - | |||
| 1399046 | Buckling spring | PS/2 | Blue on oval, ULC | IBM UK | ?-1992-? | IBM Corporation 1985 | Greek layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1399570 | Buckling spring | PS/2 | Blue on oval, ULC | IBM UK | ?-1995-? | IBM Corp. 1985 | Czech QWERTZ layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1399580 | Buckling spring | AT | Blue on oval, ULC | Lexmark | ?-1993-? | Lexmark Int'l Inc 1985 | Polish QWERTZ layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1399625 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark, IBM UK | ?-1994-? | Lexmark International Inc. 1985 | Terminal keyboard; no lock lights | - | - | - | - | - | - | - | - | - | - | - | |||
| 1399912 | Buckling spring | PS/2 | Lexmark logo, ULC | Lexmark | ?-1995-? | Lexmark Int'l Inc 1984 | Model M5-2 w/trackball, L/R "click" and "drag" buttons above LLP | - | - | - | - | - | - | - | - | - | - | - | |||
| 13H6705 | Buckling spring | PS/2 | Silver on oval, ULC | Lexmark, Maxi Switch | 1994-98 | Lexmark International, Inc. 1984, or None | The only black IBM Model M; trackpoint, with keyboard/mouse connectors | - | - | - | - | - | - | - | - | - | - | - | |||
| 1403975 | Buckling spring | PS/2 | None | Lexmark | ?-1994-? | Lexmark International, Inc. 1984 | Spanish QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1403380 | Buckling spring | AT-keyboard DE9-TrackPoint | Lexmark logo, ULC | Lexmark | ?-1995-? | Lexmark Int'l. Inc. 1984 | White Model M13 with Trackpoint II | - | - | - | - | - | - | - | - | - | - | - | |||
| 1404901 | Buckling spring | PS/2 | Lexmark logo, ULC | Lexmark | ?-1995-? | Lexmark Int'l. Inc. 1984 | White Model M13 with Trackpoint II | - | - | - | - | - | - | - | - | - | - | - | |||
| 2003809 2054858 | Buckling spring | PS/2 | White GE/Marquette logo on dark gray rectangle, ULC | Unicomp | 2006-2007 ?-2013 | None | For GE/Marquette medical imaging systems. Green and red sublegends on alphanumeric keys; alternate legends on F-keys and number pad. 12 number pad keys are bright yellow; some have red Emerg Save key at F12. Tech-support info panel applied above LLP or F-keys. | - | - | - | - | - | - | - | - | - | - | - | |||
| 20L2532 | Buckling spring | PS/2 | None | Unicomp | 2002–2005-? | None | Usually has some custom legends / sub-legends; some seen with colored key caps. | - | - | - | - | - | - | - | - | - | - | - | |||
| 41G3576 | Buckling spring | PS/2 | Gray on oval, ULC | IBM | ?–1996–? | IBM Corp. 1984 | Observed on repurposed p/n 1394618 | - | - | - | - | - | - | - | - | - | - | - | |||
| 41G3600 | Buckling spring | PS/2 | Silver on black oval, URC | Lexmark | ?–1995 | Lexmark International, Inc. 1984 | Dark grey industrial version of Space Saving Keyboard | - | - | - | - | - | - | - | - | - | - | - | |||
| 42H1292 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark, IBM UK | 1995-96 1995-97 | Lexmark International Inc. 1984 / none | One of final Lexmark-made p/n's | - | - | - | - | - | - | - | - | - | - | - | |||
| 42H1292U | Buckling spring | PS/2 | Blue on oval, ULC | Unicomp | 1996- | Unicomp, Inc. 1984 | Optional AT/DIN adapter | - | - | - | - | - | - | - | - | - | - | - | |||
| 51G8572 | Buckling spring | PS/2 | Gray or blue on oval, ULC | IBM, Lexmark, IBM UK | 1992-97 | IBM Corp. 1984, Lexmark International, Inc. 1984 | Made for IBM RS/6000 system, w/internal speaker for system "beeps"; R Ctrl key says Ctrl/Act | - | - | - | - | - | - | - | - | - | - | - | |||
| 52G9658 | Buckling spring | PS/2 | Blue on oval, ULC | IBM, Lexmark | ?-1993-? | IBM Corp. 1984; Lexmark International, Inc. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 52G9700 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | 1993-99 | Lexmark International, Inc. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 59G7980–59G7981 | Buckling spring | AT | Blue on oval, ULC | Lexmark | 1993 | Lexmark International, Inc. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 60G0817 | Rubber dome | PS/2 | Blue on oval in white rectangle, URC | IBM | ?-1995 | Lexmark Intl. Inc. 1984 | Model M2 w/full-size case; shipped with IBM PS/1 PC | - | - | - | - | - | - | - | - | - | - | - | |||
| 60G3571 | Buckling spring | PS/2 | Blue on oval, ULC | IBM, Lexmark | 1994-? | IBM Corp. 1984; Lexmark International, Inc. 1984 | Sold separately to retail customers as part of IBM's "Easy Options" program | - | - | - | - | - | - | - | - | - | - | - | |||
| 70G8638 | Rubber dome | PS/2 | Gray or blue on oval or OEM logo, ULC | Lexmark | ?-1994-? | Lexmark International. Inc. 1984 | Silkscreen-printed keycaps | - | - | - | - | - | - | - | - | - | - | - | |||
| 71G4621 | Rubber dome | PS/2 | Blue on oval, ULC | Lexmark | ?-1996-? | Lexmark International, Inc. 1984 | Danish QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 71G4622 | Rubber dome | PS/2 | Blue on oval, ULC | Lexmark | ?-1995-? | Lexmark International, Inc. 1984 | Dutch QWERTY layout, 1378705, EC1391461 | - | - | - | - | - | - | - | - | - | - | - | |||
| 71G4625 | Rubber dome | PS/2 | Gray on oval, ULC | Lexmark | ?-1993-96-? | Lexmark International, Inc. 1985 | German QWERTZ layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 71G4627 | Rubber dome | PS/2 | Blue on oval, ULC | Lexmark | ?-1994-? | Lexmark International, Inc. 1985 | Hebrew sub-legends | - | - | - | - | - | - | - | - | - | - | - | |||
| 71G4630 | Rubber dome | PS/2 | Blue on oval, ULC | Lexmark | ?-1994-? | Lexmark International, Inc. 1984 | Italian QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 71G4635 | Rubber dome | PS/2 | Blue on oval, ULC | Lexmark | ?-1994-? | Lexmark International, Inc. | Russian QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 71G4638 | Rubber dome | PS/2 | Blue on oval, ULC | Lexmark | ?-1993-? | Lexmark International, Inc. 1984 | Spanish QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 71G4643 | Rubber dome | PS/2 | Blue on oval, ULC | Lexmark | ?-1995-? | Lexmark International, Inc. 1985 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 71G4644 | Rubber dome | PS/2 | Blue on oval, ULC | Lexmark | ?-1993-95-? | Lexmark International, Inc. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 71U4623 1387530 1378706 EC | Rubber dome | PS/2 | Blue on oval, ULC | Lexmark | ?-1995-? | Lexmark International, Inc. 1985 | Swedish QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1387526 | Buckling spring | PS/2, AT | Black on square silver metal, URC | IBM UK | ?-1984-86-? | IBM CORPORATION | Danish QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 1390137 | Buckling spring | PS/2, AT | Black on square silver metal, URC | IBM UK | ?-1986-87-? | IBM CORPORATION | Danish QWERTY layout | - | - | - | - | - | - | - | - | - | - | - | |||
| 8131276 | Buckling spring | RJ25 | Blue on square, URC | IBM UK | ?-1997 | IBM Corp. | - | - | - | - | - | - | - | - | - | - | - | ||||
| 8184692 | Buckling spring | PS/2 | Gray on oval, ULC | Lexmark | 1994 | Lexmark International, Inc. 1984 | Soft Touch Keyboard with greased springs | - | - | - | - | - | - | - | - | - | - | - | |||
| 82G2383 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | 1993-99 | Lexmark International, Inc. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 82G2384 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | ?-1995-? | Lexmark International, Inc. 1984 | Spanish | - | - | - | - | - | - | - | - | - | - | ||||
| 82G2385 | Buckling spring | PS/2 | Blue on gray oval, ULC | Unicomp | 1999 | None | French | - | - | - | - | - | - | - | - | - | - | - | |||
| 82G3281 | Buckling spring | PS/2 | Blue on gray oval, ULC | Lexmark | 1994-95 | Lexmark International, Inc. 1984 | White Model M13 w/trackpoint, two connectors for keyboard and mouse | - | - | - | - | - | - | - | - | - | - | - | |||
| 82G3295 | Buckling spring | PS/2 | Blue "IBM", ULC | Lexmark | ?-1995-? | Lexmark International, Inc. 1984 | - | - | - | - | - | - | - | - | - | - | - | ||||
| 92G7453 92G7454 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | 1995 | Lexmark Int'l. Inc. 1984 | Sold separately to retail customers as part of IBM's "Easy Options" program | - | - | - | - | - | - | - | - | - | - | - | |||
| 92G7453 | Buckling spring | PS/2 | Blue on oval, ULC | Manufactured for IBM by Lexmark | 1994 | Lexmark Int'l. Inc. 1984 | Sold separately to retail customers as part of IBM's "Easy Options" program | - | - | - | - | - | - | - | - | - | - | - | |||
| 92G7455, 92G9757 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | 1993–95 | Lexmark Int'l. Inc. 1984 | Model M5-2 w/trackball, L/R "click" and "drag" buttons above LLP | - | - | - | - | - | - | - | - | - | - | - | |||
| 92G7461 | Buckling spring | PS/2 | Blue on oval, ULC | Lexmark | ?-1995-? | Lexmark Int'l. Inc. 1984 | White Model M13 with Trackpoint II; optional mouse port | - | - | - | - | - | - | - | - | - | - | - | |||
| 96U1114 | Rubber dome | PS/2 | Unicomp logo on LLP | Unicomp | ?-2000-? | - | Model M5-2 w/trackball, L/R "click" and "drag" buttons above LLP | - | - | - | - | - | - | - | - | - | - | - | |||
| UB40416 | Buckling spring | PS/2 | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 101-key, black w/light gray keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UB4041A | Buckling spring | USB | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 101-key, black w/light gray keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UB40446 | Buckling spring | PS/2 | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key, black w/light gray keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UB4044A | Buckling spring | USB | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key, black w/light gray keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UB40P36 | Buckling spring | PS/2 | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 103-key Ultra Classic, black w/light gray keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UB40P3A | Buckling spring | USB | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 103-key Ultra Classic, black w/light gray keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UB40P46 | Buckling spring | PS/2 | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key Ultra Classic, beige w/classic light/dark beige keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UB40P4A | Buckling spring | USB | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key Ultra Classic, beige w/classic light/dark beige keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UB40R46 | Buckling spring | PS/2 | Unicomp | Unicomp, Inc. 1984 | 104-key | - | - | - | - | - | - | - | - | - | - | - | |||||
| UB4ZPHA | Buckling spring | USB | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key Ultra Classic, black with light/dark beige keys, for Apple Mac OS | - | - | - | - | - | - | - | - | - | - | - | |||
| UNI041A UNI0416 | Buckling spring | USB | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 101-key, beige w/classic light/dark beige keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UNI0446 | Buckling spring | PS/2 | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key, beige w/classic light/dark beige keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UNI044A | Buckling spring | USB | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key, beige w/classic light/dark beige keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UNI0P46 | Buckling spring | PS/2 | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key Ultra Classic, beige w/classic light/dark beige keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UNI0T56 | Buckling spring | PS/2 | None | Unicomp | ?-2003-? | 122-key, for PC/5250 emulators; produces standard 101-key scancodes mapped to standard keys with modifiers | - | - | - | - | - | - | - | - | - | - | - | ||||
| UNIZPHA | Buckling spring | USB | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key Ultra Classic, beige with light/dark beige keys, for Apple Mac OS | - | - | - | - | - | - | - | - | - | - | - | |||
| UNZ2416 | Buckling spring | PS/2 | White GE/Marquette logo on dark gray rectangle, ULC; Unicomp logo on LED panel | Unicomp | ?-2002-? | - | For GE/Marquette medical imaging systems; features similar to 2003809 | - | - | - | - | - | - | - | - | - | - | - | |||
| UW40P4A | Buckling spring | PS/2 | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key Ultra Classic, black w/white keys | - | - | - | - | - | - | - | - | - | - | - | |||
| UW4ZP4A | Buckling spring | USB | Unicomp logo on LLP | Unicomp | ?-Present | Unicomp, Inc. 1984 | 104-key Ultra Classic, black w/white keys, for Apple Mac OS | - | - | - | - | - | - | - | - | - | - | - | |||
| XR4R4G6 | Buckling spring | PS/2 | Unicomp logo on LLP | Unicomp | ?-2008-? | - | Black trackpoint w/two connectors for keyboard and mouse | - | - | - | - | - | - | - | - | - | - | - | |||
| Part number | Switch type | Detachable keycaps | Detachable cable | Interface | Drainage channels | Logo type/position | Manufacturer | Dates of manufacture | Copyright | Features | - | - | - | - | - | - | - | - | - | - | - |
| Part number | Switch type | Detachable keycaps | Detachable cable | Interface | Drainage channels | Logo type/position | Manufacturer | Dates of manufacture | Copyright | Features | Key Caps | Cable | - | - | - | - | - | - | - | - | - |
Note: Manufacture dates are approximate.