IBM Model F keyboards

IBM's fifth generation of keyboards (aka, IBM Keyboard F, IBM Type F or IBM Model-F)

Contents

Background

IBM Keyboard F (or Model F as per their printed marketing designation) constitutes IBM's fifth generation of keyboards created in 1981 and produced until around 1994 to 1996. The Model F family shares strong design familiarity between its members and a single switch design much like the previous Model B family but unlike the following Model M family, as Model Fs are all buckling spring keyboards with capacitance sensing with a similar sort of internal assembly. In terms of general recognition, Model Fs are often overshadowed by their successor family; but whilst the average Model F keyboard layout is generally more archaic than the average Model M layout, Model Fs make up for it with their overall superior reliability and technical benefits both provided by the use of capacitance-sensing PCBs instead of membrane assemblies. The Model F's quality auditory and tactile feedback helped cement the original IBM PC as a quality and popular machine, and amongst people who have tried both Model F and Model M keyboards, you'd be hard-pressed to find someone who didn't prefer the key-feel of Model Fs.

History

In a nutshell, the Model F was the first group of keyboards to employ buckling spring key-switches. The idea of buckling springs by IBM was first patented as the "catastrophically buckling compression column switch and actuator" in 1971 and was invented by Richard Hunter Harris^[1][1]
IBM - Catastrophically buckling compression column switch and actuator [accessed 2022-07-04]., the man also partially responsible for inventing the beam spring key-switch^[2][2]
IBM - SCHALTTASTE MIT EINER SCHNAPPMECHANIK [accessed 2022-07-04]. of the previous Model B family. The original patent as-is was never employed on an actual production keyboard but it establishes the basic premise of a buckling spring used in a keyboard switch design and the goal of combining tactility, actuation, pre-travel and return force in one spring. The Model Fs actually use the 1977-patented IBM "buckling spring torsional snap actuator" switch^[3][3]
IBM - Buckling spring torsional snap actuator [accessed 2022-07-04]., a refinement of one of the three types of designs described in the original 1971 patent. The first Model F keyboard assembly can be found in July 1981's IBM System/23 Datamaster computer and [eventually] came in two forms; the more familiar integrated keyboard assembly (IBM 5322 "desktop" type) and the rarer separate keyboard unit (IBM 5324 "floortop" type)^[4][4]
Wikipedia - IBM System/23 Datamaster [accessed 2022-07-04].. Both had 83 keys.

A month after the Datamaster's launch, IBM released the original IBM Personal Computer (5150) that quickly far eclipsed the earlier system. The 5150 is the ancestor of all modern "x86" PCs^[5][5]
Wikipedia - IBM Personal Computer [accessed 2022-07-04]., but the system's initial success was undoubtedly aided by its included keyboard - the IBM PC Keyboard. In January 1982, Byte Magazine said "it is, by none, the best keyboard on any microcomputer"^[6][6]
Byte Magazine - Volume 07 Number 01 - The IBM Personal Computer [accessed 2022-07-04].. Today, this keyboard is referred to as the "Model F/XT" after March 1983's^[7][7]
Wikipedia - IBM Personal Computer XT [accessed 2022-07-04]. IBM PC/XT (5160) that also used this keyboard as a way to contrast it against later models. Its internal keyboard assembly is the same as the Datamaster's, just the controller electronics are different.

Outside of PCs, Model Fs also became IBM's keyboard of choice for its terminal and enterprise systems for the next 2 years. In January 1982, IBM released the 5291 Display Station^[8][8]
IBM - IBM 5291 Display Station Parts Catalog (#S131-0635-0) [accessed 2022-07-04]. featuring a keyboard unit very similar to the IBM 5324 Keyboard but slightly smaller and featuring its characteristic three-setting riser-style feet. This feet arrangement and its size gave it the nickname "bigfoot". By Q4 1982, IBM developed three new Model F keyboard assemblies for use with the IBM 4704 Display Terminal, a part of the IBM 4700 Finance Communication System. IBM first released the 50-key Model 100 Functional Keypad for the 4704-1 in October 1982, which was closely followed by the 62-key Model 200 Alphameric Keyboard and 77-key Model 300 Expanded Alphameric Keyboard in December 1982. Around a year later, the 107-key Model 400 Administrative Keyboard arrived for the 4704-2^[9][9]
kishy.ca - The IBM 4704 [accessed 2022-07-04].. All four IBM 4704 keyboards are known for their cast zinc outer casing, making the Model 400 the heaviest known Model F but even the smaller keyboards are heavy by general keyboard standards. Announced in December 1982^[10][10]
IBM - IBM 3104 Display Terminal Brief Description of Announcement, Charges, and Availability (#ZG82-0322) [accessed 2023-01-06]. and March 1983^[11][11]
IBM - IBM 3178 Display Station Brief Description of Announcement, Charges, and Availability (#183-034) [accessed 2023-01-06]. respectively, the IBM 3104 Display Terminal and IBM 3178 Display Station were released as cheaper replacements for earlier IBM 3270 series terminals and came in two models with slightly different keyboards - 3104-B1/3178-C1 with a 75-key data entry keyboard and 3104-B2/3178-C2 with an 87-key typewriter keyboard respectively^[11][11]
IBM - IBM 3178 Display Station Brief Description of Announcement, Charges, and Availability (#183-034) [accessed 2023-01-06].. For 3178 only, C1 and C2 would be followed by a 3178-C3 the following quarter and a 3178-C4 by February 1984^[12][12]
IBM - IBM 3178 Display Station Model C4 Announced Brief Description of Announcement, Charges, and Availability (#184-015) [accessed 2023-01-19]., both with 87-key EBCDIC typewriter keyboards. All IBM 3178 keyboards are known for having solenoids inside.

Also in 1983, Model Fs became the platform of significant keyboard layout development with the 104-key and 122-key terminal keyboards, both technically in the lineage of the Model B-based IBM 4978 122-key Extended Keyboard. The 104-key "function key keyboard" (aka, "unsaver") was announced in March 1983 and first shipped in July 1983 with the IBM 3290 Informational Panel^[13][13]
IBM - IBM 3290 Information Panel Brief Description of Announcement, Charges, and Availability (#183-033) [accessed 2022-07-04]., crucially sporting a layout very close to the modern ISO layout used by many regional layouts outside the United States. The "unsaver" also introduced IBM scancode set 3. Contrary to common belief, the 122-key Model F arrived later, being announced in October 1983 and made available by Q1 1984 for the IBM 3270 Personal Computer (5271)^[14][14]
IBM - IBM 3270 Personal Computer Brief Description of Announcement, Charges, and Availability (#183-129) [accessed 2022-07-04].. The "F122" added an 18-key numeric keypad area to the 104-key design and would later be followed on and developed further by four subsequent 122-key Model M types.

After 2 years of terminal keyboard releases, IBM finally released a new PC-orientated Model F in the form of an F/XT variant for the IBM Portable Personal Computer (5155) in February 1984. The 5155 was a luggable version of the PC/XT^[15][15]
Wikipedia - IBM Portable Personal Computer [accessed 2022-07-04]., thus it made sense the F/XT was reused for it. The internal assembly was largely the same mechanically and electronically, although 5155 F/XTs have an aluminium backplate instead of steel likely to reduce weight. The entire case is also plastic and the keyboard has a compartment for the cable to be stored in when the keyboard is folded up against the front of the host system. In August 1984, IBM introduced the last wholly new Model F design for the IBM Personal Computer/AT (5170)^[16][16]
Wikipedia - IBM Personal Computer/AT [accessed 2022-07-04].. Technically speaking, this so-called Model "F/AT" represented a big step towards the now-standard PC keyboard design with its introduction of the ANSI-style large left shift key, separated numeric keypad and LED lock-lights to the IBM keyboard family. It's also known for introducing IBM scancode set 2 to keyboards, which out of the three classic IBM scancodes turned out to have the most 'staying power' as even some desktop PCs today still support it via a PS/2 port.

After 1984, no new Model F assembly designs were introduced due to the family being supplanted by the then-new Model M family. Production for standard PC-orientated Model Fs was terminated by the end of the 1980s, however, some Model F keyboards remained in production at least as late as 1994. The 104-key Model F was produced as late as 1992 by IBM United States^[17][17]
kishy.ca - IBM 1387033: Space Unsaver [accessed 2022-07-04]., the 122-key Model F for the IBM 3270 PC was withdrawn from marketing in August 1994^[18][18]
IBM - Withdrawal: Selected PC Features, Options, and Publications (#194-263) [accessed 2022-07-04]., and the 5291 Model F was produced as late as 1994 by Lexmark^[19][19]
deskthority - IBM Model F 1397950 "Bigfoot" [accessed 2022-07-04]. (the company formed by IBM's divesture of their US-based keyboard, typewriter and printer production at Boulder, Colorado and Lexington, Kentucky in 1991^[20][20]
Los Angeles Times - IBM Planning to Set Up New Subsidiary : Industry: A buyout firm will be the majority owner of its typewriter and keyboard operations [accessed 2022-07-04].). Evidence for production after 1994 is minimal, but it's said Lexmark was at least refurbishing 5291/5292 Model Fs as late as 1996 (despite erroneously identifying them as "Model M" on their rear label)^[21][21]
Unicomp - IBM 5291 Model F Keyboard [accessed 2022-07-04].. There is no evidence Unicomp ever produced Model Fs, thus 1996 is likely the last possible year of Model F production.

Design

Capacitance-sensing PCB

All Model F keyboards sport a flexible capacitance-sensing PCB at the centre of their inner keyboard assembly. IBM referred to these PCBs as pad cards and they're made up of many pairs of capacitive contacts that the rest of the key-switch mechanisms (the rockers on the bottom of the buckling springs) are held above. When the above switch mechanism moves closer to the contacts, a change in capacitance is measured and eventually registers a key press when the capacitance reaches a certain threshold. This is in fact inverse to how the previous Model B keyboard family's beam spring switches operated, which rested at high capacitance and registered key-presses when the capacitance diminishes when its mechanism (the beam spring's capacitive plate) is raised from the pad card. The use of capacitance sensing allows for N-key rollover (provided the rest of the controller and possible hosts support it) and is extremely reliable.

Buckling spring key-switches

More information: IBM buckling spring#Capacitive

Buckling springs take the form of a spring that when pressed deforms (buckles) in a specific way that allows a flipper (also called rocker or hammer) to hit the circuit underneath to make a connection. In the case of Model F keyboards, pressing the switch will cause the flipper to rest atop a pair of capacitive contact pads and register a key-press. The flipper itself is made of a capacitive material. This contrasts with the buckling springs found on the later Model M keyboards that when buckling the flipper physically bridges two contacts on a membrane assembly. To differentiate the two implementations, the Model F's buckling springs are generally referred to as capacitive buckling springs to refer to its sensing method.

Buckling springs are a clicky-tactile switch considered by some to be the quintessential good clicky switch. The properties of both features are rather unique as there are seldom switches that feature a similar mechanism. It is best described as having a crisp, pingy click that perfectly matches the point of key-switch actuation, and having tactility suited for typing but also not over the top. Buckling springs on Model Fs are rated for 100 million key presses and are also on the heavier feeling side of switches, although they are a tad lighter and crisper than Model M buckling springs.

Internal assembly

All Model F keyboards are not monoblocks, instead featuring an inner keyboard assembly separate from the outer case. The typical Model F keyboard assembly is a sandwich of the following distinct layers:

Model F assemblies are secured together with several tabs surrounding the edges of the assembly, contrasting the plastic rivets most Model Ms employ. This means that the main longevity concern with Model Ms does not apply to Model Fs, but the foam layer is a possible cause for concern as it can invariably degrade with age. However, foam degradation typically doesn't result in a major technical fault with the typical side effect being that keys are more prone to rotating in their place. It only really becomes a significant issue if one opens up the assembly and allows the old foam to uncompress. Replacing the foam layer in a Model F is a documented procedure on deskthority.

Solenoid

IBM 3101, 3104 and 3178 Model F keyboards are known for having a solenoid inside the keyboard. These were called "clicker assemblies" (or some variation of) and were used for indicating when the keyboard was enabled by its host terminal/program and in some causes for issuing conditional cues. In recent times, it's also been theorised that it was used to enhance audible feedback, in some ways comparable to the sound pollution of a mechanical typewriter, but this hasn't been confirmed in literature. The practice of including solenoids inside keyboards was more widespread with the preceding Model B family and extinct for the succeeding Model M family, but for this handful of Model F keyboards it would engage for each key-press to generate a distinct sound. The practice was likely viewed as 'excessive' by the 1980s and these Model Fs only included them since they were for terminals that either had an earlier Model B keyboard with an included solenoid available for it or directly evolved from terminals that had Model B keyboards with included solenoids. As of late though, solenoids in keyboards have seen somewhat of a resurgence in popularity, thus IBM 3178 keyboards and Ellipse's reproduction F62 and F77 are sometimes sought after specifically for their solenoids or possible support of them.

PBT dye-sublimated keycaps

Model Fs are known for their high-quality unique-mount PBT dye-sublimated keycaps. Versus the most common keycap material, ABS^[25][25]
WASD Keyboards - Mechanical Keyboard Guide [accessed 2022-07-01]., PBT is more durable, does not degrade/yellow with age, UV or heat exposure, and will keep its texture for longer without shining^[26][26]
Switch And Click - ABS vs PBT Keycaps: What’s the Difference? [accessed 2022-07-01].. Dye-sublimation is also a very durable text printing method that sinks dye material into the keycap's plastic itself, meaning there is nothing to quickly wear off as would be the case with pad-printing or silk screening. This means many vintage Model F keycaps will still be in good condition, requiring at most a good cleaning.

Model F keycaps are uni-profile, meaning a given keycap can be swapped with another provided they are of the same unit size. This allows every Model F to have innate layout customisability without the user needing to worry about mismatches in keycap sculpting - sculpture is instead provided by the curved internal keyboard assembly. Furthermore, some Model Fs such as the 104-key and 122-key terminal keyboards have two-piece keycaps that allow the user to swap around their layout around without needing to completely dismount the entire keycap. The two pieces are known as the stem (the part that always stays in the barrel) and the keytop (the part that can be easily swapped). That said, most Model F variants that are easily accessible these days lack these. Model F and (buckling spring) Model M keycaps are fully interchangeable granted the correct unit size, thus Model F keycaps can be replaced with Model M keycaps including Unicomp keycaps. Today, Unicomp offers keycaps in a variety of colours and as blanks or with dye-sublimated legends on their website. They can be bought individually or as part of the many predefined sets they offer^[27][27]
Unicomp - Buttons [accessed 2022-07-26]..

Rear labels

More information: Keyboard Rear Labels topic

Model F keyboards can feature strong documentation of the keyboard's type and date of manufacture in the form of a real label sticker casually referred to as a 'birth certificate'. This practice is best associated with Model Ms as early Model Fs featured weaker documentation, but Model Fs produced after 1982 generally have external and internal labels of some sort.

External rear labels

The external rear label is used to display information about the keyboard as a whole and when present is stuck to the bottom outer case piece. As a summary of the main data points of interest presented on the external rear label:

Internal rear labels

The internal rear label is used to display information about just the inner keyboard assembly and its fitted keycaps rather than the whole keyboard and when present is stuck to the keyboard assembly's backplate. It doesn't represent the type or revision of controller or outer case of the whole keyboard. As such, multiple unique outer part numbers can share the same internal part number as evidenced by the fact the IBM Personal Computer Keyboard P/N 1501100 and IBM System 9000 Family Standard Keyboard P/N 4780898 share the same P/N 4584656 inner assembly. This is because both keyboards share the same layout and pad card, with the only differences being with the outer case and what host system the keyboard was bundled with.

Naming

Official

Somewhat like Model Bs, Model Fs were a keyboard family largely found in enterprise rather than in markets where marketing speak in the keyboard's name would be needed to drive sales or identity (ie, consumers, home, etc.). As such, many Model Fs [that were intended for one system only] were officially named after their host system with maybe an extra term referring to its intended operator use like "Data Entry" or "Typewriter" in the name. For example, IBM 3178-C3 EBCDIC Typewriter Keyboard or IBM 3180 Display Station Keyboard Element. Even for the early IBM PC keyboard releases, they were named after their host system like "IBM Personal Computer AT Keyboard". Model Ms would later start practices such as descriptive naming, the inclusion of marketing buzzwords and naming after a specific technology employed. The closest Model Fs got to this was referring to the IBM 3104/3178 keyboards as "IBM Base Keyboard" and the 104/122/127-key keyboards as "IBM Converged Keyboard"^[35][35]
Admiral Shark's Keyboards - Official names discovered for IBM 75/87/104/122 key terminal keyboards [accessed 2023-09-25]..

Some Model F lines employed sequential numbering for its members like Model Ms famously did under Lexmark in the 1990s, but it wasn't a universal or consistent practice. IBM 4704 Display Terminal keyboard models were numbered Model 100 (50-key keyboard) through 400 (107-key keyboard) and IBM 3178 Display Station keyboards took model numbers C1 through C4 after its host system. But both conventions are unrelated and limited to just those keyboards.

Community

Modern Model F naming is largely based on the host system's numbers or the number of keys a model has. For example, IBM 3178 keyboards are always simply called "3178" rather than writing or speaking their full name plus whether they're data entry or typewriter version. IBM 4704 and 122-key keyboards are almost always referred to simply by their number of keys plus an "F" at the start to differentiate against possible Model M versions of the same keyboard; "F50" (IBM 4704 Model 100), "F107" (4704 Model 400), or "F122". The IBM PC keyboards are generally referred to by the two letters IBM assigned to the two follow-ups to the original PC - XT and AT. Thus, the original IBM PC Keyboard is generally referred to as "F/XT" and the IBM PC/AT Keyboard as "F/AT" - both also with or without the "/", spoken as an initialism. To stress specific features or sizes, some nicknames are also given like "unsaver" for the 104-key Model F "unsaver" to describe the oxymoronic nature of it being a "space-efficient" version of an even-larger keyboard but still as large as some modern full-size keyboards, and "battleship" for 122-key Model Fs to highlight their sheer size.

Keyboards

System/23 Datamaster Keyboard (1981)

The IBM System/23 Datamaster was the first bearer of a Model F keyboard assembly and a buckling spring keyboard at large. The system could come in two versions; IBM 5322 "desktop" and 5324 "floortop". The 5322 was essentially a monocoque with the keyboard integrated into the computer's chassis and case, but the 5324 had a discrete keyboard although both are mechanically identical. The Datamasters were released in July 1981, one month ahead of the more famous IBM Personal Computer that reused the same keyboard assembly (albeit with a different controller board) and thus started the Model F/XT lineage. This keyboard's physical layout was based on the earlier Model B IBM 5251 and 5252 keyboards and would go on to be adapted for various other early Model F keyboards. Both keyboards are noted for their large bezels.

5150/5160 Personal Computer Keyboard (1981)

eg, P/Ns 1501100, 1501101, 1501102, 1501104, 1501105, 1503206, 1801449, 8116083, 8529297

The IBM 5150 Personal Computer was an Intel 8088-based microcomputer released in August 1981 that thanks to its open architecture and software support became the basis of the "x86" PC family that continues to dominate desktop and laptop PCs to this day^[5][5]
Wikipedia - IBM Personal Computer [accessed 2022-07-04].. The IBM Personal Computer Keyboard is the most common and widely considered to be the definitive Model F keyboard. After debuting with the 5150, it was later reused with the IBM 5160 Personal Computer XT released in March 1983^[7][7]
Wikipedia - IBM Personal Computer XT [accessed 2022-07-04]. which is what the the PC Keyboard derives its common nickname from - F/XT. The F/XT played an important role in establishing the PC as a high-quality computer and solidifying buckling spring-based keyboards as IBM's go-to for well over a decade after its release. Relative to the competition, the F/XT brought unsurpassed reliability and build quality to the mix but arguably suffered from a layout too different from others. Most notably, the F/XT along with its predecessor and successors are criticised for their use of stepped multi-unit keys to reduce the need for stabilisers outside of the spacebar.

Electronic Typewriter Models 65, 85 and 95 (1982)

The IBM Electronic Typewriter models 65, 85 and 95 were briefly available as IBM's Selectric successor using capacitive buckling spring keyboard assemblies. Introduced in 1982, they're essentially an intermediary step between the aforementioned Selectric typewriter family and Model M-based Actionwriter/Wheelwriter/Quietwriter family but are far less common than both. They replaced the Selectric's notable whiffletree mechanism with a low-power computer that drives the "golfball" print head with solenoids instead. They are the smallest alphanumeric Model Fs and use plastic rivets to hold their keyboard assembly together much like their Model M successors.

5291/5292 Display Station Keyboard (1982)

529X type Model F

The IBM 5291 Display Station (Models 1 and 2) was an IBM 5250-compatible terminal first released in January 1982 that was designed to be a low-cost replacement for the IBM 5251 Display Station Models 1 and 11 from the late 1970s. Model 1 and 2 differed on the monitor and lower-unit arrangement. The IBM 5292 Color Display Station is a variant of 5291 that adds 7-colour support to the display^[41][41]
IBM - IBM Data Communications Concepts (#GC21-5169-4) [accessed 2022-06-21].. The IBM 529X Keyboard was the earliest discrete terminal Model F keyboard in production, resembling the IBM 5324 Floortop Keyboard and using the same internal keyboard assembly as Type I Model F/XTs. Its physical and functional layouts are derived directly from the 525X-83 type Model B keyboard. The 529X is noted for its combined F1 to F24 row across its number keys originally used for inserting, deleting and moving data and controlling cursor position, and its "Cmd" (command) key used to access [host-stored] programmable command functions. A notch is present on the left side of the protrusion above the keyboard assembly to help old templates used for writing function names onto^[43][43]
IBM - IBM 5291 Models 1 and 2 Display Station Operator's Guide (#GA21-9409-2) [accessed 2023-01-21]. License/note: document archived by bitsavers.. The 529X Keyboard lacked a controller that could generate scancodes, making the keyboard essentially 'brainless' on its own. Compared to its stylistically similar 5324 counterparts, the 529X Keyboard is slightly smaller. But the 529X Keyboard famously features three-setting riser feet that is presently the largest known IBM keyboard feet, which coupled with its bezel size earns this keyboard the nickname "bigfoot" in the modern keyboard community. The original IBM 5291 Model 1 version of the keyboard connected internally to the terminal via a 14-pin IDC connector, whereas the 5291 Model 2 (and presumed 5292) versions used the more familiar external DA-15 connector.

System 9000 Family Standard Keyboard (1982)

The IBM Instruments Computer System 9000 Keyboard (P/N 4780898) is a variant of the Model F/XT introduced in May 1982 for use with the titular IBM CS/9000 laboratory computer. It's mechanically identical to the IBM PC Keyboard but lacks flip-out riser feet, traded the square IBM badge for a rectangular one reading "IBM System 9000", and its cable now sprouts out from the left side of the keyboard instead of the back. Due to IBM's repositioning of the CS/9000 as a family of computers in 1984 (the CS/9000 proper was also renamed System 9001), this keyboard later became known as the Standard Keyboard due to the availability of the System 9002's Hybrid Keyboard.

6580 Displaywriter System Type B Keyboard (1982)

The IBM 6580 Displaywriter System was a diskette-based word processing system that was originally released in June 1980^[46][46]
Wikipedia - IBM Displaywriter System [accessed 2022-12-19]. with a Model B-based keyboard. In November 1982, IBM announced this optional low-profile alternative designated the "Type B" keyboard with the original keyboard retroactively designated "Type A". The Model F-based Type B keyboard is plug-compatible with the original keyboard but is far thinner and is capable of being adjusted for 5-degree and 12-degree typing angles which IBM then touted as being "ergonomically designed"^[47][47]
IBM - Low Profile Keyboard for the IBM 6580 Displaywriter System Announced (#ZG82-0309) [accessed 2022-12-19].. The Type B keyboard features the same functional layout as the 96-character Type A keyboard. In a way, the keyboard's alphanumeric section provides an early glimpse into what would become the ISO layout with 1985's IBM Enhanced Keyboard, making the Type B one of the most modern-looking early Model F keyboards.

4704 Display Station Model 100 Functional Keypad (1982)

4704-100 type Model F

The 50-key IBM 4704 Display Station Model 100 was the first and smallest keyboard for the IBM 4700 Finance Communication System's 4704 Display Station, introduced in October 1982. It's the second smallest known alphanumeric Model F assembly behind the Model F-based IBM Electronic Typewriter models 65, 85 and 95. It's a matrix-style keypad with three key segments, usually featuring 45 transparent keys and 5 hard-set function keys. The Model 100 acted as a sort of macro pad for the system by allowing the user to map functions to those 45 transparent keys and put custom labels underneath them. It's colloquially referred to as the "F50". Its internal assembly design would later be altered to become the Model M-based IBM 50-key Keyboard.

4704 Display Station Model 200 Alphameric Keyboard (1982)

4704-200 type Model F

The 62-key IBM 4704 Display Station Model 200 is the smallest alphanumeric keyboard for the IBM 4700 Finance Communication System's 4704 Display Station, introduced in December 1982 alongside the 77-key Model 300. The Model 200 was intended to be the most basic full input device for the 4704, providing only limited user-assigned functions. Nicknamed "Kishsaver" after kishy.ca who introduced them to the modern keyboard community, these have become very desirable due to it being an example of an early 60%-layout keyboard. Starting in 2016, Model F Labs has developed and marketed a modernised recreation of the Model 200 designated as "F62".

4704 Display Station Model 300 Expanded Alphameric Keyboard (1982)

4704-300 type Model F

The 77-key IBM 4704 Display Station Model 300 is an intermediate-sized alphanumeric keyboard for the IBM 4700 Finance Communication System's 4704 Display Station, introduced in December 1982 alongside the 62-key Model 200. The Model 300 is essentially the same as the Model 200 but comes with an additional 15-key transparent-capped keypad on the right-hand side of the keyboard for user-assigned functions. Starting in 2016, Model F Labs has developed and marketed a modernised recreation of the Model 300 designated as "F77".

3104/3178 Data Entry Base Keyboard (1982)

31XX-75 type Model F

The IBM 3104 Display Terminal and 3178 Display Station were both low-cost terminals announced in December 1982 and March 1983 respectively. The IBM 3104 was intended for IBM 8100 Information System or IBM 4321 and 4331 Processor applications^[10][10]
IBM - IBM 3104 Display Terminal Brief Description of Announcement, Charges, and Availability (#ZG82-0322) [accessed 2023-01-06]., whereas IBM 3178 was designed to be used in a 'traditional' 3270 setting by connecting to an IBM 3274 Control Unit or 3276 Control Unit Display Station^[11][11]
IBM - IBM 3178 Display Station Brief Description of Announcement, Charges, and Availability (#183-034) [accessed 2023-01-06].. Despite that, both were IBM 3270 Information Display System family terminals and provided IBM 3278 Model 2 equivalent functionality but did not support many 3278 optional features.

Along with its typewriter-like counterpart, the 3104/3178 Data Entry Keyboard is a part of the IBM Base Keyboard family that originated in 1977 during the Model B keyboard era^[35][35]
Admiral Shark's Keyboards - Official names discovered for IBM 75/87/104/122 key terminal keyboards [accessed 2023-09-25].. Specifically, this 75-key keyboard uses the physical layout from the 327X-75 type Model B keyboard. It constituted only 1 of the 4 total 3104/3178 keyboard variants, which was used exclusively with 3104 Model B1 and 3178 Model C1. It lacked the right-most keypad that the typewriter version of the keyboard had, but whereas earlier IBM 3270 family keyboards were also physically smaller when they lacked one, the 75-key 3104/3178 keyboard was the same size as its 87-key counterpart but simply had a blanking plate covering where the keypad would normally go. The 75-key keyboard assembly's barrel plate is shorter than the 87-key's, meaning it cannot be 'upgraded' to an 87-key physical layout without replacement parts and a replacement barrel plate. Being a data entry keyboard, it had a functional layout similar to an IBM Card Punch Keyboard. B1 and C1 keyboards seem to share part numbers.

Amongst Model Fs, the 3104/3178 keyboard design was very distinct. They had a large area of unused space above the keys (a trait shared with only the 3101/7485 Terminal Keyboard), with only a single blue-coloured toggle switch and silver-square IBM badge consistently interrupting it. This switch was used for toggling the terminal's display between mixed-case or uppercase-only characters and gives these keyboards their common nickname "blue switch Model F". Some 3104/3178 keyboards may have what appears to be a compartment outline in this area, which was likely the result of shared tooling with the aforementioned 3101/7485 keyboard that had a compartment in this location for covering DIP switches - for 3104/3178 keyboards, it had no purpose. Just above the keys, a very pronounced raised section spanning the width of all the keys was present which can be used to hold small items or layout diagrams in place. Underneath the keyboard, there was a compartment used for storing the host terminals' Problem Determination Guide for convenience. Whilst 3104/3178 keyboards had no native retractable feet for adjusting typing angle, there were clip-on feet (P/N 5641299) available. Another notable feature of the 3104/3178 keyboards was their included solenoids used as a "keyboard clicker" that would engage as an audible confirmation for a registered key. The clicker could be toggled on or off with the bottom-right-most key of the left 4x2 key bank. 3104/3178 keyboards had a grey cable terminating in a male DA-15 plug.

3104/3178 Typewriter Base Keyboard (1982)

31XX-87 type Model F

The IBM 3104 Display Terminal and 3178 Display Station were both low-cost terminals announced in December 1982 and March 1983 respectively. The IBM 3104 was intended for IBM 8100 Information System or IBM 4321 and 4331 Processor applications^[10][10]
IBM - IBM 3104 Display Terminal Brief Description of Announcement, Charges, and Availability (#ZG82-0322) [accessed 2023-01-06]., whereas IBM 3178 was designed to be used in a 'traditional' 3270 setting by connecting to an IBM 3274 Control Unit or 3276 Control Unit Display Station^[11][11]
IBM - IBM 3178 Display Station Brief Description of Announcement, Charges, and Availability (#183-034) [accessed 2023-01-06].. Despite that, both were IBM 3270 Information Display System family terminals and provided IBM 3278 Model 2 equivalent functionality but did not support many 3278 optional features.

Along with its data entry counterpart, the 3104/3178 Typewriter Keyboard is a part of the IBM Base Keyboard family that originated in 1977 during the Model B keyboard era^[35][35]
Admiral Shark's Keyboards - Official names discovered for IBM 75/87/104/122 key terminal keyboards [accessed 2023-09-25].. Specifically, this 87-key [EBCDIC typewriter] keyboard uses the physical layout from the 327X-87 type Model B keyboard. It constituted 3 of the 4 total 3104/3178 keyboard variants, differing by how the right-most keypad and program function (PFxx) keys were utilised and taking their model name after their host; 3104 Model B2, 3178 Model C2, 3178 Model C3 and 3178 Model C4 (there was no 3104 equivalent to the latter two). B2/C2 used an typewriter-like keyboard with a 12-key keypad dedicated to PFxx keys, C3 used an typewriter-like keyboard with a combination 12-key numeric keypad with 24 PFxx legends (2 per key), and C4 used an typewriter-like keyboard with a combination 12-key numeric keypad with 12 PFxx legends^[50][50]
IBM - IBM 3178 Display Station Operator Reference Guide (#GA18-2128-3) [accessed 2022-11-27].. C3 and C4 were also only available in US English and uniquely sport decimal and tab keys on their 12-key keypads^[51][51]
IBM - IBM 3270 Information Display Station Character Set Reference (#GA27-2837-9) [accessed 2022-11-27].. B2 and C2 keyboards seem to share part numbers.

Amongst Model Fs, the 3104/3178 keyboard design was very distinct. They had a large area of unused space above the keys (a trait shared with only the 3101/7485 Terminal Keyboard), with only a single blue-coloured toggle switch and silver-square IBM badge consistently interrupting it. This switch was used for toggling the terminal's display between mixed-case or uppercase-only characters and gives these keyboards their common nickname "blue switch Model F". Some 3104/3178 keyboards may have what appears to be a compartment outline in this area, which was likely the result of shared tooling with the aforementioned 3101/7485 keyboard that had a compartment in this location for covering DIP switches - for 3104/3178 keyboards, it had no purpose. Just above the keys, a very pronounced raised section spanning the width of all the keys was present which can be used to hold small items or layout diagrams in place. Underneath the keyboard, there was a compartment used for storing the host terminals' Problem Determination Guide for convenience. Whilst 3104/3178 keyboards had no native retractable feet for adjusting typing angle, there were clip-on feet (P/N 5641299) available. Another notable feature of the 3104/3178 keyboards was their included solenoids used as a "keyboard clicker" that would engage as an audible confirmation for a registered key. The clicker could be toggled on or off with the bottom-right-most key of the left 4x2 key bank. 3104/3178 keyboards had a grey cable terminating in a male DA-15 plug.

4704 Display Station Model 400 Administrative Keyboard (1983)

4704-400 type Model F

The 107-key IBM 4704 Display Station Model 400 is the largest keyboard for the IBM 4700 Finance Communication System's 4704 Display Station, introduced in December 1983 with the IBM 4704-2. The Model 400 features an additional 30-key transparent-capped keypad on top of the Model 300's 77-key design, making it the most versatile and capable keyboard for the 4704 series. It also has an Alps-made counterpart for the Far Eastern markets.

104-key Converged Keyboard (1983)

eg, P/Ns 1386965, 1387033, 6016730, 6016732, 6248412, 6248413

The 104-key Model F terminal keyboard was the first in a long line of IBM Converged Keyboards with a distinct 24-key program function key bank placed above the keyboard's alphanumeric keys. Despite a common misconception stating the contrary, the 104-key keyboard came before the more common 122-key Model F ("F122"), beating it to market by several months. The original host terminal for the 104-key keyboard was the IBM 3290 Information Panel, a unique plasma-screen terminal in the IBM 3270/coaxial display station family announced in March 1983^[13][13]
IBM - IBM 3290 Information Panel Brief Description of Announcement, Charges, and Availability (#183-033) [accessed 2022-07-04]. (the first "F122" host was the IBM 3270 PC, which was announced in October 1983^[14][14]
IBM - IBM 3270 Personal Computer Brief Description of Announcement, Charges, and Availability (#183-129) [accessed 2022-07-04].). This retroactively named "model 1" was replaced by the 3290 Model 2 series in October 1985, which included the models 220 (with 104-key keyboard) and 230 (with 122-key keyboard)^[56][56]
IBM - IBM 3290 Information Panel Models 220 and 230 Replace IBM 3290 Model 1 Brief Description of Announcement, Charges, and Availability (#185-115) [accessed 2023-04-11].. Another host system, the IBM 5080 Graphics System, was announced in November 1983 as a compatible replacement to the IBM 3250 Graphics Display System that was suited for CAD/CAM work and capable of attaching to IBM System/370, 30xx and 43xx processors using 3270 protocol^[57][57]
IBM - IBM 5080 Graphics System for High Performance CAD/CAM, Data, and Engineering/Scientific Graphics Brief Description of Announcement, Charges, and Availability (#183-145) [accessed 2023-07-31]..

In addition to the 24-key program function key bank with "PFxx" nomenclature legends, the "F104" has a left-hand side 10-key function key bank similar to previous IBM 3270 keyboard designs such as the 327X-75 type and 327X-87 type Model B keyboards but with 2 extra keys. As a first for 3270-family keyboards, the "F104" sported a layout similar to what would become the "ISO" layout popularised by the IBM Model M Enhanced Keyboard. To adjust the typing angle, the keyboard had two-setting riser feet that were accessible by pushing large buttons on the keyboard's sides. Early press releases and IBM documentation photos of the IBM 3290 Model 1 typically showed a version of the "F104" with a raised border surrounding the rim of the 24-key bank section's raised platform and its silver-square IBM badge placed in the top-left corner down from it. It's unclear if this early version made it into production as no modern examples have been documented. For confirmed production examples, however, the "F104" can be divided into two types based on how they connect to their hosts. As shipped with the IBM 3290-1 and 5080, the Type I "F104" had a modular cable system consisting of a female DA-15 and male DB-25 port - the DA-15 port was for connecting either a 24/25-key Numeric or Program Function Keypad or a lighted program function keypad (LPFK), whilst the DB-25 port was for connecting the keyboard to the host terminal or graphics system. When the IBM 3290 Model 2 was introduced, the Type II "F104" was released with the same 240-degree 5-pin DIN plug "F122s" were introduced with and the DA/DB port area was blocked off with a blanking panel (users who wanted to use the 24/25-key keypad with their 3290 Model 2 was directed to purchasing the 3290-230 with a Type I 122-key Model M instead). It's unclear if the 5080 keyboard was updated the same way. Other minor differences between Type I and II is that Type I "F104s" had an adjustable clicker assembly that can be triggered when pressing keys and 4-pin DIP switch bank, whilst Type IIs lack the clicker and have an 8-position DIP switch bank in a different location to Type I's 4-pin one. The "F104" is colloquially referred to as the "unsaver" by keyboard enthusiasts either for (stemming from the misconception that "F122s" came first) to describe the oxymoronic nature of this keyboard supposedly being a 'space-efficient version' of an even larger ["F122"] keyboard despite the fact "F104" was as large as some modern full-size keyboards, or for simply being a keyboard larger than its layout needed.

24/25-key Numeric & Program Function Keypads (1983)

eg, P/Ns 6018100, 6018105, 6018109

The 24/25-key Model F keypad was a peripheral component to 104-key Model F Converged Keyboards, designed to work in tandem with such host keyboards. They are the smallest known Model F based keyboards. They were first introduced for the IBM 3290 Information Panel, a unique plasma-screen terminal in the IBM 3270/coaxial display station family announced in March 1983^[13][13]
IBM - IBM 3290 Information Panel Brief Description of Announcement, Charges, and Availability (#183-033) [accessed 2022-07-04].. In November 1983, the IBM 5080 Graphics System - another host system - was announced as a compatible replacement to the IBM 3250 Graphics Display System that was suited for CAD/CAM work and capable of attaching to IBM System/370, 30xx and 43xx processors using 3270 protocol^[57][57]
IBM - IBM 5080 Graphics System for High Performance CAD/CAM, Data, and Engineering/Scientific Graphics Brief Description of Announcement, Charges, and Availability (#183-145) [accessed 2023-07-31].. When IBM announced the 3290 Model 2 in October 1985, the company directed customers to choose the Model 230 version with a 122-key Model M Converged Keyboard if they wished to continue receiving the 24/25-key Model F's functionality^[56][56]
IBM - IBM 3290 Information Panel Models 220 and 230 Replace IBM 3290 Model 1 Brief Description of Announcement, Charges, and Availability (#185-115) [accessed 2023-04-11]..

The 24/25-key Model F was designed to match the same depth profile of the 104-key Model F ("F104"), resulting in a tall, skinny keypad. The keypad was available in two functional layouts, program function and numeric (also referred to as "calculator layout"), with the latter also having several regional and World Trade Country (WTC) variants. All program function and WTC numeric 24/25-key Model Fs had 25 keys, whereas standard numeric keypads had a 2-unit width "0" key resulting in 24 usable keys. Like the "F104", the 24/25-key Model F also had two-setting feet to adjust typing angle, but they were wider and spun most of the keypad's width and weren't side-accessible like the F104's. The keypad had a short, fixed cable with a DA-15 plug, which allowed it to connect to a host 3290-1 or 5080 keyboard (the keypad never connected to a host terminal or graphics system directly). In 1988, IBM introduced the Model M-based IBM Screen Reader Keypad (SRK) that was believed to been produced using modified (cut-down) 24/25-key Model F keypad assembly tooling as the newer keypad's assembly design bears many shared traits such as the barrel plate retaining the holes needed for the 24 or 25-key layout despite the SRK not requiring them.

4980 Display Station Typewriter Keyboard (1983)

P/N 4178208

The IBM 4980 Display Station was a twinaxial terminal for IBM Series/1 minicomputers, announced and released in October 1983. It was designed to be functionally similar to the earlier IBM 4978 Display Station whilst sporting "significantly enhanced ergonomics, expanded keyboard flexibility, reduced cabling and attachment costs and extended cable lengths"^[62][62]
IBM - IBM 4980 Display Station Model 1 Announced Attaches to Series/1 via New Feature (#1250) Brief Description of Announcement, Charges, and Availability (#183-136) [accessed 2023-08-03]..

The IBM 4980 used a IBM Converged Keyboard based 127-key Model F, a sibling design to the more common 122-key Model F Converged Keyboard. Both the IBM 4980 and the IBM 3270 Personal Computer (the first terminal/system to use an "F122") were announced the same day (18th October), but whilst the 4980 was made available the same month, 3270 PCs didn't ship until 1984 Q1^[14][14]
IBM - IBM 3270 Personal Computer Brief Description of Announcement, Charges, and Availability (#183-129) [accessed 2022-07-04].. On this technicality, the 4980's "F127" was the first "battleship" or "battleship-sized" (as modern enthusiasts call them) Model F keyboard to make it to market. Like the "F122", the 4980 keyboard at its core was an expanded version of the 104-key Model F Converged Keyboard. It's a "function key keyboard" with 24 program function keys with "PFxx" nomenclature legends placed in two rows above the keyboard's main alphanumeric keys. Like the "F104" and "F122", the "F127" came with a left-hand side 10-key function key bank similar to previous IBM 3270 keyboard designs such as the 327X-75 type and 327X-87 type Model B keyboards but with two extra keys. Unlike those keyboards, the "F127" used all usable capacitance-sensing pad pairs on the keyboard's pad card to accommodate its expanded layout. For adjusting typing angle, two-setting riser feet were present and accessible by pushing large buttons on the keyboard's sides. Although unique for "F127" was that the aforementioned buttons were pearl coloured to match the rest of the keyboard's case instead of being grey. The "F127" doesn't feature DIP switches and utilises 240-degree 5-pin DIN plugs on their coiled cables, but unlike "F122s", this keyboard doesn't seem to use IBM scancode set 3 like the "F122" as the keyboard doesn't work with Soarer's Converters^[61][61]
Wazrach @ deskthority - IBM 4980 Model F Battleship (DONE) [accessed 2023-08-03]. License/note: permission to use photos requested and given via DMs..

122-key Converged Keyboard (1983)

eg, P/Ns 1385151, 1385167, 6110344, 6110345, 6110346, 6110347, 6110668

The 122-key Model F Converged Keyboard was an expanded and prevalent version of the 104-key Model F Converged Keyboards. A sibling of the 127-key 4980 Display Station Typewriter Keyboard, the "F122" could be considered a convenient combination of the "F104" and the 24/25-key Model F keypad that was designed to operate alongside them. The first "F122" to market was the IBM 5271's Converged Keyboard for the IBM 3270 Personal Computer announced in October 1983 and available from Q1 1984, an IBM Personal Computer (5160 PC/XT based) with additional hardware and software to emulate an IBM 3270 terminal^[14][14]
IBM - IBM 3270 Personal Computer Brief Description of Announcement, Charges, and Availability (#183-129) [accessed 2022-07-04].. As such, the "F127" (which was announced and released in October 1983^[62][62]
IBM - IBM 4980 Display Station Model 1 Announced Attaches to Series/1 via New Feature (#1250) Brief Description of Announcement, Charges, and Availability (#183-136) [accessed 2023-08-03].) technically beat the "F122" to market. By March 1984, the "F122" was adopted for IBM's then-new generation of lower-cost terminals - the 3179 and 3180 series. The IBM 3179 Model 1 Color Display Station was a low-price but plug-compatible replacement for the IBM 3279 Color Display Station Models S2A and S2B^[64][64]
IBM - IBM 3179 Color Display Station Brief Description of Announcement, Charges, and Availability (#184-039) [accessed 2023-01-23].. The IBM 3180 Display Station was a monochrome counterpart to 3179 and was available in a 3270-compatible Model 1 and 5250-compatible Model 2. The 3180-1 was designed to provide IBM 3278 Model 2 through 5 Display Station functionality, and the 3180-2 provided 5251 Model 11 Display Station functionality^[65][65]
IBM - IBM 3180 Display Station Models 1 and 2 Brief Description of Announcement, Charges, and Availability (#184-040) [accessed 2023-01-23]..

Besides its sheer size (for which this keyboard earned the modern nickname "battleship" or "battleship-sized" keyboard), the "F122" is recognisable for its 24-key program function key bank inherited from the "F104". Those keys will generally have a "PFxx" nomenclature on 3270-family keyboards and "Cmdxx" nomenclature on 5250-family keyboards, with some isolated examples sporting simply "Fxx". The "F122" also retained the left-hand side 10-key function key bank similar to previous IBM 3270 keyboard designs such as the 327X-75 type and 327X-87 type Model B keyboards but with 2 extra keys. "F122s" had two-setting riser feet that were accessible by pushing large buttons on the keyboard's sides, allowing users a choice of 6-degree, 12-degree or 18-degree typing angle^[64][64]
IBM - IBM 3179 Color Display Station Brief Description of Announcement, Charges, and Availability (#184-039) [accessed 2023-01-23].. Unlike the "F104" however, most "F122s" used 240-degree 5-pin DIN plugs on their coiled cables. 3270 PC, 3179-1 and 3179-G^[66][66]
ASK Keyboard Archive - P/N 1385151 (1985, IBM-US) [accessed 2023-08-01]. License/note: photos donated by theMK#1822, CC BY-NC-SA 4.0. "F122s" generally have an 8-position DIP switch bank present, whilst 3180-1^[67][67]
kishy - IBM 6110345: 122-key Model F [accessed 2023-08-01]. and 3180-2^[68][68]
ASK Keyboard Collection - SNKB-F1986-FBS-122 [accessed 2023-08-01]. License/note: CC-BY-NC-SA 4.0. keyboards lack them. Besides the "F127", two distinct variants in utility and features exist - the IBM 3205 Color Display Console Keyboard (3270-family operator console version of "F122") and IBM TPC Keyboard III (TEMPESTed version of the IBM 5271's Converged Keyboard).

System 9002 Hybrid Keyboard (1984)

The IBM System 9002 Hybrid Keyboard was a Model F/XT-based keyboard designed for the IBM CS/9000. It served as a counterpart to the original System 9000 Family Standard Keyboard that integrated a similar keyboard assembly with a 57-key functional membrane touch panel, replacing the dedicated touch panel found on previous IBM System 9000 family computers. The name "Hybrid" refers to the use of both capacitive buckling spring key-switches and a membrane touch panel for the keys, which contrasts the Standard Keyboard which was simply a rebadged IBM PC Keyboard with minor modifications. The housing for the keyboard is likely a variation of the IBM 104-key terminal keyboard's case, meaning this is in fact also a hybrid of two Model F keyboard designs. It is very likely the Hybrid Keyboard is the rarest Model F presently known.

5155 Portable Personal Computer Keyboard (1984)

The IBM Portable Computer Keyboard was a rehoused Model F/XT made for IBM's first luggable PC - the IBM 5155. Due to its intended use for a portable PC system, the design was lightened by using an all-plastic case and an aluminium keyboard assembly backplate instead of a steel one. The keyboard is also intended to fold up on the front of the host 5155, so there are now two mechanisms on the bottom of the keyboard used for releasing the keyboard so that it can fold down and for detaching the keyboard completely. The keyboard retains a form of riser-style feet, but handles used to fold them down now serve as hinges when the keyboard is coupled to its host and now are also spring-loaded to allow them to be the release mechanism for decoupling the keyboard entirely.

5170 Personal Computer AT Keyboard (1984)

eg, P/Ns 1503092, 6450200, 6450221, 6450222, 6450223, 6450225, 8286165

The IBM Personal Computer AT Keyboard was the successor to the IBM PC and PC/XT Keyboards (Model F/XT) as IBM's main PC keyboard and is the last wholly unique Model F design and capacitive buckling springs host introduced. It was released at the same time as its host PC, the IBM Personal Computer AT (PC/AT) in August 1984, which was the final major release of the original IBM PC series^[16][16]
Wikipedia - IBM Personal Computer/AT [accessed 2022-07-04].. What's now commonly referred to as the "Model F/AT" represented a big step towards the now-standard PC keyboard design with its introduction of the ANSI-style large left shift key, separated numeric keypad and LED lock-lights to the IBM keyboard family. However, it would be quickly supplanted by the IBM Model M Enhanced Keyboard within two years. As the name implies, the F/AT uses the "AT" protocol (IBM scancode set 2) like later PS/2 keyboards. This meant that until the 2010s, F/ATs were considered the most valuable Model F keyboards as were amongst the few Model F variants that were easily adaptable to modern systems.

3101/7485 Terminal Keyboard (1984)

The IBM 3101/7485 Display Terminal Keyboard was a low-profile replacement for the original Model B-based IBM 3101/7485 keyboard and was introduced in August 1984^[70][70]
IBM - IBM 3101/7485 Display Stations Enhanced Brief Description of Announcement, Charges, and Availability (#184-154) [accessed 2023-01-20].. The IBM 3101 ASCII Display Terminal was a serial-based terminal that used RS-232C and RS-422 for short and long-distance communication respectively^[71][71]
Wikipedia - IBM 3101 [accessed 2022-11-27].. The 3101 was originally rolled out in October 1979^[72][72]
IBM - DPD chronology page 5 [accessed 2022-11-27]. and was used with IBM System/1 minicomputers and IBM 8100 Information Systems^[49][49]
IBM - An Introduction to the IBM 8100 Information System (#GA27-2875-7) [accessed 2022-11-27]. License/note: photos used under fair dealing.. The IBM 7485 Display Station is believed to be a 3101-based terminal available under RPQ. The low-profile 3101/7485 keyboard is based on the IBM 3104/3178 Typewriter Keyboard (31XX-87 type Model F) which happens to already use essentially the same physical layout as the original 3101 keyboard and has a compartment useful for the 3101 keyboard's dip switch bank. Notably, the low-profile 3101/7485 keyboard lacks the 3104/3178 keyboard's characteristic blue-coloured switch used for toggling the terminal's display between mixed-case or uppercase-only characters, giving these their nickname "blue switchless" Model F. However, the 3101/7485 keyboard retains a solenoid.

3205 Color Display Console Keyboard (1984)

eg, P/Ns 1385082, 1385490, 1385492, 1385494, 1385495, 1385497, 1385498, 1385499, 1385503, 1385504

The IBM 3205 Color Display Console was a colour terminal announced in October 1984 intended for operator console usage for the System/370 compatible IBM 4361 and 4381 processors. It replaced the IBM 3278 Model 2A Display Console and IBM 3279 Model 2C Color Display Console used for earlier IBM 4300 series processors^[74][74]
IBM - IBM 3205 Color Display Console Brief Description of Announcement, Charges, and Availability (#184-149) [accessed 2022-12-19]..

The 122-key console keyboard for the IBM 3205 was a cosmetic variant of the regular 122-key Model F Converged Keyboard and technically a successor to the 327X-OC type Model B keyboards the IBM 3278-2A and 3279-2C used (which in turn was also a modification of another keyboard). The 3205 "F122" sported characteristic green "Start" and yellow "Stop" keys, reminiscent of the earlier 327X-OC type Model B (albeit those had a red "Stop" key instead). In other respects, the 3205 "F122" is the same as a regular "F122" including having the characteristic 24-key program function key bank with "PFxx" nomenclature, two-setting riser feet for adjustable typing angle, and 240-degree 5-pin DIN plugs on their coiled cables. The 3205 "F122" also had an 8-position DIP switch bank that must be set when the 3205 is connected to a host processor, with the latter 5 switches used in combination to set language. A 124-key Japanese/Katakana version of the keyboard for the IBM 3205 also existed^[75][75]
IBM - IBM 3205 Color Display Console Maintenance Information (#SY18-2121-1) [accessed 2022-12-19]..

EMR, EMR II & TPC I Keyboards (1985)

The IBM EMR and TPC I Keyboards were late variants of the Model F/XT featuring different cables and shielding around the internal logic board. These keyboards were designed to be compliant with the shielding specification of codename TEMPEST, a NATO-recognised U.S. National Security Agency specification regarding protecting against spying with electronic equipment. In particular, these keyboards were designed to not radiate electromagnetic emanations to counter Van Eck phreaking. IBM referred to them as 'TEMPESTed' keyboards. The host systems for the EMR Keyboards are unclear, however, the IBM TPC Keyboard I was designed for the IBM 4450 TPC I, a TEMPESTed version of the IBM 5150 PC^[77][77]
IBM - IBM Personal System/2 and IBM Personal Computer Product Reference Version 4.0 (#102682986) [accessed 2022-07-04].. EMR "one" Keyboard features a shielded 5-pin DIN plug, however, EMR II Keyboard and IBM TPC Keyboard I have a DE-9 plug. Known part numbers are limited and only US English TEMPESTed Model F keyboards have been found. P/Ns 100A535 and 100A536 are EMR II Keyboards and P/N 4003444 is the TPC I Keyboard.

TPC Keyboard III (1986)

P/N 1385072

The IBM 4456 TEMPEST PC III (aka, TPC III or TPC3) was a version of the IBM 3270 Personal Computer^[77][77]
IBM - IBM Personal System/2 and IBM Personal Computer Product Reference Version 4.0 (#102682986) [accessed 2022-07-04]. that had been 'TEMPESTed' to be compliant with the shielding specification of codename TEMPEST, a NATO-recognised U.S. National Security Agency specification regarding protecting against spying with electronic equipment. In particular, they were designed to not radiate electromagnetic emanations to counter Van Eck phreaking. It's presently unclear when the 4456 was released, but the sole keyboard example found was made in 1986^[79][79]
WorthPoint - RARE VERSION IBM Model F TPC Keyboard iii 1385072, Vintage 1986 with Cover [accessed 2022-07-04]. License/note: used under fair dealing..

As its host system is a variant of an existing IBM terminal emulator PC with a 122-key Model F Converged Keyboard (the IBM 5271's Converged Keyboard), the TPC Keyboard III retains the general characteristics of that keyboard. It was a 122-key Model F Converged Keyboard variant with a 24-key program function key bank with "PFxx" nomenclature legends. It also retained the two-setting riser feet that are side accessible to allow the user to change typing angle. However, instead of using a coiled cable terminated with a 240-degree 5-pin DIN plug, the TPC Keyboard III has a straight cable with a DE-9 connector much like other TPC keyboards. Despite the different connector, it's possible the TPC Keyboard III still uses IBM scancode set 3 as EMR II/other TPC keyboards can be passively adapted to the connector of their non-TEMPEST counterparts^[80][80]
daneli @ deskthority - Using the EMR II keyboard [accessed 2023-08-03].. The original IBM 5271 keyboard had an 8-position DIP switch bank and it appears that was retained for the TPC Keyboard III, albeit with an additional cover piece. Another difference compared to other "F122s" is that TPC Keyboard III used a 1-unit backspace key and a 2.25-unit left shift key instead of 2-unit and 1.25-unit keys respectively.

TPC Keyboard IV

The IBM TPC Keyboard IV was a TEMPESTed version of the Model F/AT. The IBM 4459 TPC IV was a TEMPESTed version of the IBM 5170 PC/AT^[77][77]
IBM - IBM Personal System/2 and IBM Personal Computer Product Reference Version 4.0 (#102682986) [accessed 2022-07-04].. Like other TPC keyboards, the TPC Keyboard IV has a DE-9 plug and was designed to be compliant with the shielding specification of codename TEMPEST, a NATO-recognised U.S. National Security Agency specification regarding protecting against spying with electronic equipment. The only known part number is 4010504.

Model F Labs F62 & F77 Reproductions (2015)

Starting in 2015, Model F Labs has created and sold replicas of two IBM 4704 keyboard designs marketed under their common nicknames; F62 (Model 200) and F77 (Model 300). Model F Labs is solely run by deskthority regular Ellipse. There's a "classic" and modern-esque styled "ultra compact" version of either model available. From most viewable angles, the classic keyboards are largely faithful replicas but there are some changes under the hood and on the bottom. The ultra compact keyboards sports an original case design. In terms of changes from the original IBM 4704 keyboards, these have natively USB-compatible controllers that support xwhatsit or QMK firmware. Vial firmware can also be flashed to allow for easy key remapping and macro creation. The long bottom foot that the original keyboards had has been deleted, replaced by the option to have F/XT-style cork pads to simply prevent the keyboard from sliding around and prevent scratching, or threaded or screwed bumper-style feet for which the classic keyboards have two holes and the ultra compact keyboards have four. The default inclusion varies between the classic and ultra compact^[82][82]
Model F Labs - Keyboard Feet / Bumpers [accessed 2022-08-21].. Also gone is the buzzer and control dial for it, replaced by the option to fit a solenoid. Finally and most obviously, the keyboard's default layout has been modernised whilst options for many alternative layouts are given.

Further reading & resources

Internal

External

Sources

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

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