31XX-75, 31XX-87, 3178, 340X and 380X type Model Fs

The 75-key IBM 3104/3178 Data Entry Keyboard and 87-key IBM 3104/3178 Typewriter Keyboard (collectively the IBM 3104/3178 Base Keyboards) are a series of 3270-style terminal keyboards first announced in December 1982 for the IBM 3104 Display Terminal and reused the following year for the IBM 3178 Display Station. They are casually known as IBM's "blue switch" keyboards due to their prominent blue toggle switch. Both are ultimately within the IBM Model F keyboard family, but they also belong to the overarching IBM Base Keyboard lineage that began during the IBM Model B era with 1977's 327X-75 type and 327X-87 type Base Keyboards for IBM 3276, 3278 and 3279 Display Stations (amongst others). The 75-key and 87-key 3104/3178 keyboard designs constitute the 31XX-75 and 31XX-87 type Model Fs, respectively.

Their layouts and use of a solenoid as a clicker assembly were products of this relation to earlier Base Keyboards. However, to suit the 1980s' refined ergonomic demands, these keyboards are much lower profile than their '70s counterparts thanks to the use of clicky capacitive buckling spring keyswitches instead of beam springs. They were also amongst the last of IBM's terminal keyboards before they employed their more modern and refined 104-key and 122-key IBM Converged Keyboards. The keyboards existed as at least five submodels designated B1 and C1, B2 and C2, C3, C4, and C8 that primarily differed by their lack/inclusion of a 12-key program function keypad and what functional layout it may have. The 87-key design was ultimately modified to become the IBM 3101/7485 "blue switchless" keyboard.

Contents

Summary

History

The 3104/3178 keyboard family initially appeared with the IBM 3104 Display Terminal. The 3104 was announced on 6^th December 1982 with a planned first customer shipment for January 1983. 3104 is a 3270-style terminal that is functionally equivalent to an IBM 3278 Model 2 Display Station or 8775 Model 1 Display Terminal, but it does not connect coaxially to typical IBM 3270 control units such as a 3274 Control Unit or a 3276 Control Unit Display Station, nor does it support all of 3278-2's and 8775-1's accessories. Instead, it connects serially via Synchronous Data Link Control (SDLC) to an IBM 8100 Information System or an IBM 43X1-family System/370 compatible processor via an IBM 3843 Loop Control Unit. It was available in two major models: B10 (often shortened to just B1) with a 75-key data entry keyboard and B20 (B2) with an 87-key EBCDIC typewriter keyboard.^[1] Submodels B1A, B1C, B1K, B1S, B2C, B2D, B2K and B2S are also known.^[15]

On 8^th March 1983, IBM announced the IBM 3178 Display Station as the other, more prominent host for these keyboards with a planned first customer shipment for April 1983. 3178 is also a 3270-style terminal, but compared to 3104, it is of a more traditional 3270 design as it attaches coaxially to the aforementioned control units 3274 and 3276. Via a display printer adapter, 3178s could also be attached to IBM 43X1 family System/370 compatible processors.^[2] 3178 is plug compatible with the IBM 3278 Model 2 Display Station, but it does not support every 3278 feature such as programmed symbols or selector light pen attachment.^[3] The 3178 was available in two launch models that mirrored 3104's; C1 with a 75-key data entry keyboard and C2 with an 87-key typewriter keyboard.^[2]

The 3178 received at least three further models. On 7^th June 1983, IBM announced the 3178 Model C3 Display Station for a planned first customer shipment in September 1983.^[5] On 7^th February 1984, IBM announced the 3178 Model C4 for a planned first customer shipment in April 1984.^[6] Both are similar to 3178-C2, but are U.S. English only and both port a Model B-era RPQ layout to the 31XX-87 design. The C3 layout is identical to the RPQ 8K1038 327X-87 type Model B for 3278 Model 2s, whereas the C4 layout is identical to the RPQ 8K0932 327X-87 type Model B for 3278 and 3279.^[6] By May 1985, an IBM 3178 Model C8 Display Station had also been ++released and used a keyboard with the same keyboard ID as C3.^[18] It was as an entirely RPQ release^[19], and it is presently unseen.

It is unclear exactly when production for 3104 or 3178 keyboards stopped, but there are some potential indications for when the 3178 was considered obsolete by IBM and production of parts for it slowed. It is at least known that IBM 3178 models C1 through C4 were still on the market as of December 1987.^[20] But by the end of the decade, IBM started trade-in programs to allow customers to turn in their old IBM 3270 or 5250 family terminals for a discount on more modern systems on a one-for-one basis. On 21^st February 1989, such a program was started for customers of selected Personal System/2 or RT PC models to receive $100 USD credit (~$253 adjusted for inflation for 2024) for turning in various terminals, including 3178.^[21] On 20^th March 1990, another program was started for customers of InfoWindow 3471 or 3472 Display Stations to receive $90 USD credit (~$216 in 2024) for turning in 3178s.^[22]

1991 is currently the latest observed production year for a 3178 keyboard.^[23] It is also known that IBM withdrew 3104 models B1A, B1C, B1K, B1S, B2C, B2D, B2K and B2S from marketing as late as 6^th December 1997^[15], but it is unclear how this relates to their keyboard production timeline.

Design

Keyswitches

More information: IBM buckling spring#IBM capacitive-type

3104/3178 keyboards use IBM capacitive buckling spring keyswitches like all other Model Fs. In fact, they were also the first IBM 3270-family terminal keyboards to use them. The IBM buckling spring is a family of clicky keyswitches that served as IBM's primary keyswitch technology from 1981 to about 1996 across the Model F and Model M keyboard families. The buckling spring itself is an actuator design comprised of a metal coil spring and a pivot plate, where force applied to the coil spring will eventually cause it to kink, which moves the pivot plate into a position that can be sensed. There is some key travel remaining after sensing, allowing for part-way actuation. The design also allows the actuation point and peak tactility to be matched. Its feel and sound profile they can produce are completely unique since buckling springs are just so different to other, typical keyswitches.

This capacitive variant of IBM buckling springs was exclusively used by Model F family keyboards, using a capacitance-sensing PCB known as a pad card to sense when the pivot plate is pressed parallel to it. This coupling of buckling spring and pad card is very advantageous, allowing for a minimum reliability of 100 million key presses and inherent N-key rollover. Key travel is approximately 4.2mm^[26] (~0.165"). Capacitive buckling springs are known for their linear-like smoothness that is interrupted by a sharp, precise tactile event.

3104/3178 keyboards also use what are known as "XT-style" barrels.

Cover set

3104/3178 keyboards use an all-plastic cover set. It is presently unknown what plastic they use. Besides part numbers, the only other markings inside are "A.P.M.", but its meaning is also unclear. The plastic is at least known to be weaker than that of most other Model Fs, so special attention and care are required when shipping the keyboard and when taking it apart.

The cover set is held together with two 3/16" (~5mm) flanged hex-head with slot screws. On the front lip, there is a single clip from the top piece to the bottom, roughly centred. On the back, there are three tabs from the top piece to the bottom. Once unscrewed, the clip can be pushed to release the top piece from the bottom. The top piece can then be lifted from the front until it clears the monocase/dualcase switch, and then it can be pulled away so the tabs at the back can clear.

Guide access panel

All 3104/3178 keyboards have a guide access panel (known as a pocket) via their bottom cover piece. It is approximately 225mm wide.^[ASK-M] This pocket would typically house some sort of guide for the host terminal for easy access when needed. Known documents include:

Keypad cover piece (31XX-75 only)

3104-B1/3178-C1 keyboards lack a dedicated keypad as it is not required for their data entry layouts. Whereas the previous Model B Base Keyboards existed in two different sizes to accommodate this, the Model F Base Keyboards instead use one cover set size and the B1/C1 keyboard's disused keypad is covered up by a blanking plate instead. The top cover piece for any 3104/3178 keyboard has three plastic poles for holding a keypad cover piece in place, which is then fastened by metal when fitted.

Setup switch access panel (3104 only)

3104 keyboards have an access panel surrounding the monocase/dualcase switch that can lift to access their setup switch compartment. On the inside of the door, there should also be a sticker with a key describing what each switch does. Due to shared tooling, some 3178 keyboards (typically the earlier ones) may have the compartment as well, but it is likely shut from the inside-out via a screw or a piece of metal holding the latch in place. A lot of later 3178 keyboards may lack the compartment altogether.

Assembly

Inside a 3104/3178 keyboard is a curved keyboard assembly called a complete sub-assembly (CSA) that is comprised of four layers: the keyboard frame, the foam layer, the pad card, and the base plate.

Removal

The CSA is secured to the bottom cover piece via two nut-fastened flanged hex-head screws and two plastic retainer clips. It can be removed by unscrewing them with a flat-head screwdriver whilst ensuring the nut below does not move, and then sliding the CSA off the clips. Due care is required as both the screw holes and the retainer clips are known potential breakage points.

Keycaps

More information: IBM Model F keyboards#PBT dye-sublimated keycaps

3104/3178 keyboards use dye-sublimated PBT keycaps in a pearl and pebble scheme, typical for most Model F family keyboards.

Feet

Whilst 3104/3178 keyboards do not possess any built-in feet for adjusting typing angle, they at least have holes on their bottom cover piece to allow two clip-on feet to be attached. Such feet had part numbers 5641297^[27], 5641298^[18] (a pair of), and 5641299 (singular).

Controller card

3104/3178 keyboards have used several controller card variants that could differ in size, colour, jumper configuration and setup switches. Four controller card part numbers are currently known:

The large controller cards are the older of the two styles and are universal to both 3104 and 3178 keyboards. As 3104 requires setup switches, all three known variants have at least pin footprints for up to three DIP switch banks and up to three Texas Instruments 5615947s or 74155s. No spec sheet has been found for the former TI chip, but the latter is a decoder/demultiplexer.^[38] The largest chip is an Intel 8310354 (likely 8049 compatible^[39]) microcontroller with a 1977 copyright date, sometimes adorning a sticker with the part number "1385377" on it. It is not uncommon to see these PCBs with yellow patch wires applied on one or both sides. At present, only one part number of the small-style controller card is known. Due to its lack of any DIP switch support, this one is likely a 3178 exclusive. It otherwise uses the same Intel 8310354 microcontroller.

Layout jumper header

As many of the 3104/3178 controller card designs are shared by various models, they all have a 7-position (7x2-pin) jumper header used for keyboard ID (KBDID) purposes. They are used to indicate the exact keyboard layout style (87-key versus 88-key, data entry versus typewriter, etc.) On the small controller card variant, this header is located in the top right corner of the PCB (closest edge to the clicker assembly). On the large controller card variants, this header is located relatively close to the bottom-left corner of the PCB.

3104/3178 keyboards may have a "KEYBOARD WSE MAINTENANCE INFORMATION" sticker somewhere on the inner side of its bottom cover piece that indicates some possible jumper options. The known configurations are:^[18]

X indicates a jumper present, * indicates a jumper can be used to inhibit the numeric lock feature

Setup switches

3104 keyboards uniquely have two banks of eight DIP switches present under an access panel above the keys and surrounding the monocase/dualcase switch. 3104 keyboards will also only have one of the large controller card variants to provide them. Due to shared lineage, 3178 keyboards may inherit some nuances for would-be DIP switch support. 3178 keyboards with one of the large controller card variants will have footprints and traces for the DIP switches, though usually unused. Some 3178 keyboards may have the DIP switches, but they will serve no purpose when used with a 3178 Display Station and are often inaccessible even if an access panel is present.

3104 keyboards should have a sticker on the inside of the access panel's door with a key indicating the switches' functions. All switches of the first bank are used for setting a Synchronous Data Link Control (SDLC) address field value, with each switch setting a bit to make a 1-byte address. SDLC is the serial protocol used by IBM Systems Network Architecture (SNA), which is what the IBM 8100 Information System is primarily intended to use and how 3104 communicates with 8100. SDLC was designed to supersede older standards like Binary Synchronous Communication (BSC) and Start-Stop (S/S).^[41] After a beginning flag, the address field is the first byte transmitted in an SDLC transmission frame and is used to identify the device sending or receiving a given frame.^[42]

The second bank is used for setting carrier/data rate (switches 1 through 4), NUM LOCK (switch 5), and system copy (switch 6). Switches 7 and 8 are unused. NUM LOCK is a feature of IBM 3270-style data entry keyboards that allows the user to lock the keyboard into numeric mode, which will cause the keyboard's overlay numeric keypad to always be active whilst it is on.^[43] System Copy is a feature carried over from IBM 8775 Models 1 and 2 Display Terminals, allowing the terminal screen's contents to be printed when a user presses the "Print" key or when the application program requests the function.^[44]

Monocase/dualcase switch

The characteristic blue toggle switch 3104/3178 keyboards have is used as a monocase/dualcase switch. Such a switch was originally introduced for the 3270 terminal family in 1977 on the IBM 3276 Control Unit Display Station and 3278 Display Station, but placed on the terminal itself to the right of their CRT^[45] instead of their keyboards.

When the switch is set to the "monocase" position (A), the terminal will show all letters in uppercase. When the switch is set to the "dualcase" position (A, a), the terminal will show letters in their proper, original case (mixed case). The switch does not affect stored data saved on the host processor or in the terminal's character buffer, only what is rendered on screen. The switch was excluded from 76-key and 88-key Japanese (Katakana) versions of the 3104/3178 keyboards^[3], presumably as Katakana does not have different letter casing/capitalisation.

Clicker assembly

3104/3178 keyboards are noted for being one of the few Model F keyboard designs that included an internal solenoid used as a clicker assembly. Clicker assemblies were a common internal component during the Model B era, used primarily to deliver some audible cues to the operator and increase key stroke audibility.

When connected to their original host terminals, 3104/3178 keyboards could toggle the clicker function on or off via its Click key at the bottom-right of the leftmost 4x2 key bank. The clicker will never sound when in particular the Alt, Lock, Reset and Shift keys are pressed. The clicker was also used to deliver a notice to the operator if they tried to press a key when the terminal/program was under input-inhibited ("Do-Not-Enter") conditions.^[3]

Branding

3104/3178 keyboards sport a silver-square "IBM" badge in the keyboard's top-right corner. Its size is approximately 2.4cm x 2.4cm (~0.95" x ~0.95").^[ASK-M]

Rear labels

3104/3178 should have at least one rear label that describes the keyboard quite thoroughly. Besides the expected part number and country of origin, a manufacture date, the plant they were made in, their type number and their host terminal's model number could also be present. IBM U.S. rear labels typically format the date in their "DATE" field as a week number followed by the year (WW-YYYY), though some late Lexington-made examples might format it as DD-MMM-YYYY instead. IBM U.K. rear labels will always format the date in their "DATE OF MFG" field like DD-MM-YYYY.

IBM U.S. rear labels often portrayed the plant they were made at via their "PLT" field, indicating "23" for Raleigh, North Carolina and "11" for Lexington, Kentucky. Earlier 3104/3178 keyboards made in the USA are more likely to be made in Raleigh than in Lexington. IBM U.K. rear labels portray their plant via their ID number instead, indicating "55" for Greenock, Spango Valley, Scotland. The ID field for either country could also indicate a type number like "3178", "340X", or "380X". 3104/3178 rear labels also often indicate their host terminal's model via their "MODEL" (IBM U.K.) or "MOD" (IBM U.S.) field as either an abbreviated two-character value like "B2" or a full three-character one like "C30". However, IBM U.S. could sometimes leave this blank or have "F" written to indicate the keyboard is a part of the Model F keyboard family instead. IBM U.K. could also have values like "BF", which does not match any currently known 3104/3178 terminal model.

Layout

As a continuation of the IBM Base Keyboard design^[47], both the 75-key and 87-key keyboards' physical and functional layouts are based on IBM 3270 family keyboards that came before - namely the 327X-75 and 327X-87 type Model B keyboards respectively. IBM 3251, 3276, 3278, 3279 and 8775 all shared and contributed their own unique variants to the pool of '70s Base Keyboards available. 3104 and 3178 makes some omissions compared to the Base Keyboards available for them though, likely as 3104 and 3178 were intended as a low-cost terminals with only 3278 Model 2 and 8775 Model 1 functionality, and they both sat in between the 3276/3278/3279 era, and the 3179/3180/3290 era that used more versatile IBM Converged Keyboard designs.

Firstly, 3104 and 3178 have no counterpart to the earlier 75-key typewriter keyboard, only the 75-key data entry and 87-key typewriter keyboards. Functional layouts for the 87-key typewriter keyboard was also cut down to just the standard EBDBIC typewriter layout at launch and later two specific RPQ layouts via C3 and C4, meaning 3104 and 3178 have no counterparts for the ASCII Typewriter, Attribute Select Typewriter, Attribute Select Typewriter/APL, Typewriter/APL, Typewriter/Text Entry, Typewriter/Text Entry and Edit and Typewriter Overlay Keyboards. The 75-key data entry keyboard also lacks a counterpart for the Data Entry Keypunch/High Volume Keyboard.

75-key data entry layout

The 75-key physical layout was used for IBM 3104s (Model B1) and 3178s (Model C1) intended for data entry usage. The functional layout was IBM's 3270 EBCDIC Data Entry layout^[3], which can be considered a compromise between a typewriter-style keyboard and the layout previous IBM Card Punch Keyboard (024/026, 029, 129, etc.) operators would be familiar with. This layout notably has an overlay numeric keypad for easier numerical data entry and scattered program function ("PFxx") keys. Such keyboards are not designed to input different case letters; instead, it has two different shift keys for numeric mode (left shift key) and alphabetic mode (right shift key). They are also known as "upper" and "lower" shift, respectively: numeric shift accesses numbers, operators and symbols printed on the top of the keycap's face; alphabetic shift accesses the characters printed at the bottom of the keycap's face. The B1/C1 keyboard was the only variant of this style of keyboard, but was available for many locales.

87-key typewriter layout

The 87-key physical layout was used for IBM 3104 (Model B2) and 3178 (Models C2, C3, C4 and C8). The functional layout was IBM's 3270 EBCDIC Typewriter layout.^[3] Compared to data entry keyboards, typewriter-style keyboards are intended for more general purpose applications. Typewriter-style keyboards are also intended to type letters in upper or lowercase, so they have single-purpose shift keys like modern PC keyboards instead of separate numeric and alphabetic ones like data entry ones. B2/C2, C3, C4 and C8 are overall similar but primarily differ in how their 12-key program function keypad is used and in the case of C3, some minor legend changes. C3 and C4 were only available with a U.S. English functional layout, whereas B2/C2 were also available in many other locales. C8 is believed to be like C3 as they share the same keyboard ID.

Japanese (Katakana) variants

For Japan and at least for IBM 3178s, versions of the C1 and C2 keyboard designs were available with a unique physical layout and Katakana functional layout. Both gain an extra key to become 76-key and 88-key layouts, respectively.^[3] It is presently unclear if these layouts were available for the IBM 3104. The layout changes included an extra column of keys in between the alphabetic/symbol keys and the Backspace and Return keys, enlarging of said Return key to 3 units vertically, and enlarging of the left shift (at the expense of the key to its right for 75/87-key layout), number row 1 (at the expense of the key to its left for 75/87-key layout), Alt and Enter keys horizontally.

Connectivity

More information: Keyboard Connectors#3104/3178 Model F and Keyboard Scancodes#IBM 3104/3178 style scancodes

Both 3104 and 3178 keyboards use the same plug, a screwable male DA-15 plug typically with a "5" embossed on its plastic jacket. Both of their cables are also straightened (no coils) and rather thick, but can either be black (typically 3104^[9]) or grey (typically 3178) coloured. The controller card (PCB side) of the cable terminates in a 16-pin, 2.54mm IDC-style connector. The fifteenth pin on the connector and PCB header is blocked off and missing (respectively), allowing it to be used as a key. A cable tie is used to retain the cable onto the bottom cover piece.

The following describes the keyboard cable's pinout on both ends, the individual wire colours, and their functions:^[18]

Protocol

The 3104/3178 keyboard protocol does not have a specific name, but it has the distinction of the first serial-based keyboard interface in the IBM 3270 family. It transmits scancodes in 8-bit packets through the "Data" line. Basic, 2-bit host-to-keyboard commands can be sent via the "Cmd 0" and "Cmd 1" lines, though only an "initialise" command is presently documented for it.^[48]

3104/3178 keyboards use the provisionally but aptly named "IBM 3104/3178 style" scancode set as they were the first keyboard designs to use it. Whilst some scancodes (e.g., the return and forward-tab keys) are the same as the Model B-era Base Keyboards' "IBM 3276/3278 style" scancodes, most other keys are different. The 3104/3178 codeset was also adapted for use on the Type 1 104-key Model F Converged Keyboard for the IBM 3290 Model 1 Information Panel and IBM 5080 Graphics System, albeit transmitted by a parallel-based interface instead. For all later IBM 3270-style keyboards, it was succeeded by a combination of IBM PC Mode 2 keyboard protocol (Display Station variant) and IBM scancode set 3.

3104-B1 & 3178-C1

The 3104 Model B1 (3104-B1) and 3178 Model C1 (3178-C1) keyboards were one of two launch keyboard designs, alongside 3104-B2/3178-C2. The 3104-B1 was announced on 6^th December 1982^[1], whereas the 3178-C1 was announced on 8^th March 1983.^[2] The B1/C1 keyboard solely constitutes the 31XX-75 type Model F as it has the distinction of being the only 75-key (most) or 76-key (Japanese/Katakana) design for this IBM Base Keyboard generation. It was intended for data entry purposes, and IBM dropped the 75-key typewriter layout that was available for the previous generation of Base Keyboards for IBM 3276, 3278 and 3279 (etc.) Display Stations.

Typical for an IBM data entry keyboard, the layout resembles that of an IBM Card Punch Keyboard's with its lack of a dedicated keypad area and inclusion of two shift key types - a numeric shift (left) and an alphabetic shift (right). Though unlike previous Base Keyboards, IBM did not use a unique reduced form-factor cover set for this design compared to the 87-key ones, instead opting for a universal one and to use a blanking plate to cover up where a dedicated keypad could go.

3104-B2 & 3178-C2

The 3104 Model B2 (3104-B2) and 3178 Model C2 (3178-C2) keyboards were one of two launch keyboard designs, alongside 3104-B1/3178-C1. The 3104-B2 was announced on 6^th December 1982^[1], whereas the 3178-C2 was announced on 8^th March 1983.^[2] The B2/C2 keyboard was one of four keyboard designs constituting the 31XX-87 type Model F, with this one being the only one that shipped with layouts besides U.S. English. An 87-key layout was used for most, but the Japanese/Katakana layout had 88 keys.

This was the standard typewriter-style offering, designed to enable typing in both lower and upper case when the data-entry B1/C1 could not. Compared to other 87-key designs, the B2/C2 keyboard can be identified by:

3178-C3

The 3178 Model C3 (3178-C3) keyboard was a variant of the 3178-C2 Typewriter Keyboard and a part of the 31XX-87 type Model F. It was announced on 7^th June 1983, with first customer shipments expected that September.^[5] The 3178-C3 Display Station itself functions similarly to 3178-C2, just the keyboard is different and it has no 3104 counterpart. The C3 keyboard's layout was only available for U.S. English and implements a layout previously available for at least IBM 3278 Model 2 Display Stations via the RPQ 8K1038^[3] 327X-87 type Model B Base Keyboard.

Like C2's keyboard, the C3 keyboard is still typewriter style, but it has been given a dedicated numeric keypad with an adding machine arrangement and a tab key. Program function keys that were once laid across the number keys within the main keyboard area were migrated to the dedicated keypad and various shift key combinations were altered compared to B2/C2; the "PA1" and "PA2" keys were now accessible via lower shift (absence of using the Shift keys) instead of alternate shift (holding the Alt key), the "Dup" and "Field Mark" keys were now accessible in upper shift (holding a Shift key) only, and the "Clear" key became a dedicated key instead of requiring alternate shift. A "Sys $" key was added and the "Cursr Sel" key was moved down one row to make space for the aforementioned "Clear" key.^[5] In summary, C3 keyboards can be identified by:

3178-C4

The 3178 Model C4 (3178-C4) keyboard was a variant of the 3178-C2 Typewriter Keyboard and a part of the 31XX-87 type Model F. It was announced on 7^th February 1984, with first customer shipments expected that April.^[6] Like 3178-C3, the 3178-C4 Display Station functions similarly to C2 and it has no 3104 counterpart. The C4 keyboard's layout was only available for U.S. English and implements a layout previously available for IBM 3276, 3278 and 3279 Display Stations via the RPQ 8K0932 327X-87 type Model B Base Keyboard.^[6]

The C4 keyboard is still typewriter style and even has an adding machine style numeric keypad with tab key like C3's keyboard, but it instead uses the C2-style number row with PFxx legends and does not have any of the C3 keyboard's shift key combination changes. In summary, C4 keyboards can be identified by:

3178-C8

The 3178 Model C8 (3178-C8) and its keyboard are present unseen, but their existence is confirmed in IBM literature and appeared by May 1985. C8 was an RPQ unit used alongside the RPQ 8K1377 IBM 3174 Subsystem Control Unit Multiple Logic, and was available in at least submodels C80, C81 and C83.^[19] The keyboard itself (RPQ 7L0587) has a typewriter-style layout, was a part of the 31XX-87 type Model F, and uses the same KBDID as 3178-C3.^[18]

Gallery

Keyboard part numbers

48 keyboard part numbers have been found in the ASK Keyboard Part Number Database. If you believe a relevant part number is missing, you can help improve this list by requesting a submission for it to be added.

Component part numbers

Directory entries

4 keyboards have been found in the ASK Keyboard Directory.

Sources

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

ASK-M. Admiral Shark's Keyboards original measurement. Assume ± 1mm (length) or ± 10g (mass) accuracy.

ASK-T. Admiral Shark's Keyboards original terminology. This term was created to categorise, describe and/or label something that has not been clearly done so before.

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