Original specs/details

Full Name IBM 3178-C4 Display Station Typewriter Keyboard
Part NumberPart Number
The number used to describe this keyboard's specific release; usually specific for a target region, language or SKU, etc.
A designation from my own type naming scheme used to categorise this keyboard with or from others by their common features and market intent but may/may not be derived from official names.
Model F 3104/3178 Typewriter Base Keyboard
A [keyboard enthusiast] community given name for this keyboard. It can be a shortening of its name and properties, a more abstract term, a real-life reference, or metonymy.
Blue Switch
The name of the known switching mechanism that lies under this keyboard's keys.
IBM capacitive buckling springs
Original KeycapsOriginal Keycaps
The keyboard's original keycaps' material and text/symbol printing technique.
PBT with dye-sublimated legends
The style of this keyboard's flip-out or extendable feet. If applicable, this may also state how many levels of height adjustment are available and whether the feet could be rubberised.
Removable feet
The protocol(s) this keyboard can use to speak to the host computer (eg, scancode sets).
IBM 3178-specific
The keyboard-to-host connection. This is could be a description of a cable (its colour, whether its coiled, whether its detachable, and what connector is at its end) or the name of a wireless technology.
Grey straightened-style fixed DA-15 cable
Form FactorForm Factor
The standardised or universally acknowledged name for this keyboard's layout form factor.
Production Date 1985 Week 2
Acquisition Date 2021-10-25

About this keyboard type

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, 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. 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. 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. C3 and C4 were also only available in US English and uniquely sport decimal and tab keys on their 12-key keypads. 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.