Official names discovered for IBM 75/87/104/122 key terminal keyboards

On 22nd September 2023, Admiral Shark's Keyboards [re]discovered that IBM had official names for two large families of keyboards thanks to documentation on the IBM 3174 Establishment Controller (a component of the IBM 3270 Information Display System used for connecting terminals, PCs and printers to IBM host processors such as IBM System/370 mainframes). As a result, ASK content will be edited to include references to them (but will retain more common names where appropriate). This announcement will discuss my findings. For discussion, please see my /r/modelm thread on the subject.

The documents instrumental to this discovery were:

Supporting evidence:

IBM Base Keyboard

"Base Keyboard" refers to IBM 3270 terminal keyboard designs that came after the original IBM 3275/3277 (66-key and 78-key) designs but before any IBM 'function key keyboard' (104 to 127 key) designs. Previously, these designs have been referred to on ASK as 'late 3270' keyboard designs with 'early 3270' being the aforementioned 3275/3277 era keyboards. Primarily, they were Model B keyboards:

IBM 3276/3278/3279 Display Station 75-key Keyboard

Typewriter variant shown[1][1]
TheMK#1822 - donated photos. License/note: CC-BY-NC-SA 4.0.

327X-75 type Model B

IBM 3276/3278/3279 Display Station 87-key Keyboard

RPQ 8K0932 variant shown[2][2]
TheMK#1822 - donated photos. License/note: CC-BY-NC-SA 4.0.

327X-87 type Model B

It's unclear if the terminal also includes the 3276/3278-2A/3279-2C Operator Console Keyboard (327X-OC type Model B), which is a version of the 75-key IBM Base Keyboard with an integrated Operator Control Panel (OCP). Typically, the 327X-OC type was referred to as simply the "Operator Console Keyboard" in literature. However, the documents explicitly state that the Model F versions of these keyboards for IBMs 3178 were also IBM Base Keyboards:

IBM 3178 Models C2, C3 & C4 Typewriter Keyboard

C2 variant shown[ASK]

31XX-87 type Model F

As these designs were shared across many of them, terminals that used an IBM Base Keyboard by name or association include:

Converged Keyboard

"Converged Keyboard" refers to keyboards typically referred to on ASK as IBM 'function key keyboards' (keyboards with 24 function keys and a plus-shaped navigation cluster). The lineage was introduced in 1983 with the IBM 3290 Information Panel's 104-key "unsaver" Model F keyboard. "Converged" is a term I've heard before and wrote about on ASK, but I only believed it applied to IBM 3270 PC keyboards (IBM 5271/5273 Converged Keyboards). This term ultimately applies to a lot of keyboards:

122-key Model F terminal keyboard

3180 variant shown[ASK]

"F122" or "battleship"

Type I 122-key Model M terminal keyboard

3179-1 variant shown[ASK]

"M122" or "battleship"

Type II 122-key Model M terminal keyboard

3197 variant shown (note this is a 5250 keyboard)[ASK]

"M122" or "battleship"

Type III 122-key Model M terminal keyboard


"M122" or "battlecruiser"

It's unclear if the Micro Switch made 104-key Quiet Touch Keyboard, 127-key Model F, 122-key operator console Model F and Type IV 122-key Model M are included under this moniker. For example, the 127-key Model F was very specifically the IBM 4980 Display Station 127-key Typewriter Keyboard and the [IBM-branded] Type IV 122-key Model M was the IBM PS/2 Host Connected Keyboard, but the physical properties of their layout may still be considered a part of the "Converged" family for all I know (pending further clarification).

As these designs were shared across many of them, terminals that used an IBM Base Keyboard by name or association include:


It's clear these terms were used across keyboard families, with "Base Keyboards" from the Model B and Model F families existing and "Converged Keyboards" from the Model F and Model M families existing. As such, these terms seem to more describe the layout and intent of the keyboard grouped together than individual keyboards. Furthermore, "Based Keyboard" at least seemed to have only appeared once IBM Enhanced Keyboards (101-105 key Model Ms) appeared, so that term at least may have been retroactively created. Anyway, it's a nice insight into how IBM saw these keyboards and in my opinion is confirmation IBM saw "unsavers" and 122-key within the same lineage.

For ASK content, these terms will now be used to describe the two lineages. Most instances of 'function key keyboard' will likely be changed to "Converged Keyboard", and the 75-key and 87-key 'late 3270' layouts will be referred to as "75-key Base Keyboard" and "87-key Base Keyboard" respectively. If differentiating between families is needed, they may also be referred to as (for example) "75-key Model B Base Keyboard", "122-key Model M Converged Keyboard", etc.


ASK. Admiral Shark's Keyboards original content. License/note: CC BY-NC-SA 4.0.

  1. TheMK#1822 - donated photos. License/note: CC-BY-NC-SA 4.0.
  2. TheMK#1822 - donated photos. License/note: CC-BY-NC-SA 4.0.
  3. webwit - Index of /input/ibm_misc [accessed 2023-01-06]. License/note: public domain.
  4. Joe/Ellipse @ - 500+ photos of my IBM Keyboards [accessed 2022-05-02]. License/note: permission requested and explicitly given via direct correspondence.