Editing IBM 122-key terminal keyboards

{{TODO finish}}
{{infobox dkeyboard
| image name   = M122 Type III.png
| name         = Model M122
| pn           = Various (see main text)
| fcc          =
| branding     = IBM, Lexmark, Unicomp, others
| manufacturer = [[IBM]], [[Lexmark]], [[Unicomp]]
| switch       = [[IBM buckling spring#Membrane|Buckling spring over membrane]]
| layouts      = 122 [[ISO]]
| interface    = [[PS/2 interface|PS/2]], [[AT keyboard interface|AT]], [[USB]], Terminal
| weight       = 2.0–2.5 kg
| dimensions   = 557 × 232 × 59 mm<br />(21.9 × 9.13 × 2.32 in)<br />Type I & II<br />533 × 215 × 64 mm<ref name="3477announcement" /><br />(21.0 × 8.5 × 2.5 in)<br />Type III & IV with feet raised
| introduced   = 1985
| price        = $295 (1988)<ref name="3192announcement" /><br />$250 (1989)<ref name="3477announcement" />
}}

The '''IBM Model M 122''', first produced in 1985, is a 122 key keyboard originally designed by IBM for a range of their terminals and computers. It is a sibling to the 101-105-key Model M [[IBM_Enhanced_Keyboard|Enhanced Keyboard]]. It shares the Enhanced Keyboard’s Membrane [[IBM_buckling_spring|Buckling Spring]] technology, and the internal construction is very similar. M 122s used a variety of protocols, but most common is the terminal set 3 protocol. They are still produced by [[Unicomp]] today for consumers and for companies such as [https://www.affirmative.net/CustomPages/Home.aspx Affirmative Computer Products]. 

Like the Enhanced Keyboard, its manufacturing designation is Model M. It was manufactured by IBM at its plants in the US, UK and Mexico; by [[Lexmark]] and [[Maxi_Switch|Maxi Switch]]; and today by Unicomp. Like the layout of the Enhanced Keyboard, the 122 key layout was copied by number of other OEMs, appearing in keyboards such as the [[Cherry_G80-2100|Cherry G80-2100]] and the [[NMB_Hi-Tek_PC122_REV_C|NMB PC122]].

The M122 went through several major design changes throughout its life. There is no official IBM designation for the differences in designs, so users have created their own terminology to differentiate between them. The most significant design change was that from cases nearly identical to the Model F 122 to cases that are more compact and draw inspiration from the 101-105 key Enhanced Keyboard. Many users refer to the earlier, larger M122s as “battleships” and the later, smaller M122s as “battlecruisers”. To keep track of further variations, some users have adopted a system of Types: I, II, III, and IV.<ref name="shark122typecomp" />

==Design Details==

The 122 key layout is identical to that of the earlier Model F 122. Compared to a 101 key layout, it has a standard ISO alpha block, 10 additional function keys to the left of the alpha block, no Esc key, 12 additional function keys on top, a cross navigation block, and a split Numpad +. The physical layout of the M122 has remained the same throughout its life, although the functions assigned to each key vary depending on the terminal’s usage. For example, the 24 function keys can be labeled F1-24, PF1-24, or Cmd1-24 depending on the model.

Although the vast majority of M122s use IBM's Membrane Buckling Spring technology, some later M122s were made with rubber dome over membrane switches.

==Functions==

===Data Entry (DE)===

===Data Typewriter (DP)===

===Host Connected/Emulator===

==Types==
Like the Enhanced Keyboard, the M122 went through many design changes during its life. The case, keycaps, controllers, membrane layouts, lock lights (or lack thereof), and other small details all changed at some point. There are no designations of the differences in M122s in any official IBM, Lexmark, or Unicomp literature, so the "Type" classification was invented by enthusiasts to keep track of the major changes. It should be noted that "Types" are not the same as "Generations" - for example, some types were produced long enough to have different backplate thicknesses despite the outward appearance not changing<ref name="shark122typecomp" />, unlike Enhanced Keyboards. The types are in approximately chronological order.

===Type I===
The first type of M122, the Type 1, is the earliest observed. It strongly resembles the IBM Model F 122 keyboard. From the top and sides, a Type I M122 is indistinguishable from an F122. It shares the F122’s top case, large 2-level flip-down feet, and square metal badge. The top case of the F122 is made of more brittle, painted plastic, and the M122’s case is made of the same plastic used in the Enhanced Keyboard. However, it is impossible to accurately distinguish between the two from photos. The biggest external difference is the bottom case. An F122 has a black stamped-metal bottom case with a separate plastic piece on the back, while the Type I M122 has a one-piece beige plastic bottom case. There is a blanking plate on the bottom case to which dip switches are sometimes fitted.

The top case of a Type I M122, with a little modification to the inside, can be fitted to replace the top case of an F122. Many F122 owners do this because the Type I M122’s case is made of a much more durable plastic.

The Type I M122 is generally the earliest version of M122, but some examples were produced by Lexmark in the 1990s. These Lexmark-produced examples have a unique bottom case with cutouts for drainage channels not seen on early IBM-produced Type I M122s.

Type I M122s usually have the thick, rainbow-colored backplate also found on early Enhanced Keyboards. Type I M122s also feature fixed, coiled cables with 240 degree 5-pin DIN connectors.

<gallery widths=250 heights=147>
File:IBM_1389262_31MAR94.jpg|Type I M122, P/N 1389262, made by Lexmark in 1994.
File:IBM_1389262_31MAR94_back.jpg|Back view, showing large flip-down feet
</gallery>

===Type II===
The second type, the Type II, represents a cost-saving simplification of the Type I. The overall shape of the case is the same, but the F122-style flip-down feet are replaced with small Enhanced-Keyboard style feet integrated into the bottom case. Virtually everything else about the keyboard remained the same.
Type II M122s generally feature fixed, coiled cables with right-angle 240 degree 5-pin DIN connectors.

One of the most common Type II M122 part numbers was 1390702, a typewriter keyboard associated with the 3192 Display Station.<ref name="3192announcement" />

<gallery widths=250 heights=147>
File:IBM_1390702_08AUG89.jpg|Type II M122, P/N 1390702, made by IBM in 1989.
File:IBM_1390702_08AUG89_back.jpg| Back view, showing the small flip-down feet.
</gallery>


===Type III===
The third type, the Type III, included a major redesign of the case. The new case for the Type III M122 was strongly influenced by the Enhanced Keyboard, with sharp corners, small bezels, and an oval-shaped grey or blue plastic IBM badge. The bottom case has a slot running across the back allowing the user to route the cable closer to the left or ride side. Most Type III M122s have thinner, fixed, coiled cables with RJ45 connectors. Some Type III M122s have blanking plates for a lock light sticker, similar to terminal versions of the Enhanced Keyboard.


Many Type III M122s came with with IBM's Infowindow line of terminals.<ref name="3477announcement" />

<gallery widths=250 heights=147>
File:IBM_1394308_03OCT89.jpg|Type III IBM M122, P/N 1394308, made by IBM in 1989.
File:IBM_1394308_03OCT89_back.jpg|Type III IBM M122, P/N 1394308, back view.
</gallery>

===Type IV===
The fourth type, the Type IV, has several minor changes from the Type III. Type IV M122s generally have PS/2 connectors, and they feature lock lights similar to the Enhanced Keyboard. Unicomp manufactures the Type IV M122 to this day.

Some Type IV M122s have rectangular Lexmark logos or the corresponding blanking plate, similar to Lexmark produced Enhanced Keyboards and Unicomp Classic 101s. Type IV M122s were manufactured with many different badges besides IBM, Lexmark, and Unicomp, including [https://deskthority.net/viewtopic.php?f=62&t=13518&p=300401&hilit=lynk#p300401 Lynk], [https://deskthority.net/wiki/File:UNICOMP_LYNX_301-5522-01.jpg Lynx Technologies], [https://deskthority.net/wiki/File:Decision_Data_Terminal.jpg Decision Data], [https://deskthority.net/wiki/File:ComputerLab_International_M122.jpg ComputerLab International], and [https://www.affirmative.net/CustomPages/Home.aspx Affirmative Computer Products].

<gallery widths=250 heights=147>
File:AFFIRMATIVE_AC40956.jpeg| A Unicomp Made, Affirmative branded M122.
File:AFFIRMATIVE_AC40956_back.jpeg|Back view.
</gallery>


==Gallery==
===1389162===
One of the earliest documented M122s, manufactured 06 NOV 85.

<gallery widths=250 heights=147>
File:IBM_1389162_06NOV85.jpg|Front view.
File:IBM_1389162_06NOV85_back.jpg|Back view.
File:IBM_1389162_06NOV85_sticker.jpg|Sticker.
</gallery>

===1389262===
An M122 featuring rare Data Entry keycaps. It uses the 5250 layout for AS/400 and iSeries computers.
<gallery widths=250 heights=147>
File:IBM_1389262.jpg|Front view.
</gallery>

==External links==
* Admiral Shark's Keyboards [https://sharktastica.co.uk/topics/m122_diffs Comparison & classifications of 122-key Model M keyboards]
* [https://www.affirmative.net/Search/ProductView.aspx?partid=244071805&iscustom=1 Affirmative 1225T 5250/PC Keyboard]
* Unicomp [https://www.pckeyboard.com/mm5/merchant.mvc?Screen=CTGY&Category_Code=PC122 PC 122]

==References==
<references>
<ref name="shark122typecomp">Admiral Shark's Keyboards—[https://sharktastica.co.uk/topics/m122_diffs  Comparison & classifications of 122-key Model M keyboards]. Accessed 2022-03-24.</ref>
<ref name="3192announcement">IBM—[https://www.ibm.com/common/ssi/ShowDoc.wss?docURL=/common/ssi/rep_ca/7/897/ENUS188-007/index.html IBM 3192 DISPLAY STATION W MODELS]. Accessed 2022-05-12.</ref>
<ref name="3477announcement">IBM—[https://www.ibm.com/common/ssi/ShowDoc.wss?docURL=/common/ssi/rep_ca/1/897/ENUS189-131/index.html IBM INFOWINDOW 3477]. Accessed 2022-05-12.</ref>
</references>

[[Category:List of all keyboards]]
[[Category:IBM keyboards]]
[[Category:Vintage keyboards]]