This keyboard originally came into my possession with worn case texture and a yellowed set of Unicomp's sparkly blue-grey keycaps with IBM 5250 US English legends. The keyboard has been partially restored with a brand-new Unicomp PC-122 case (original lock-light overlay also transferred to the new case) and a combination of Unicomp's pearl/pebble US and 3270 PC keycap sets, and several UK ISO and custom (Fn and 1u backspace) keycaps. I plan to purchase and install a more authentic grey 5250 keycap set at the earliest convenience. This keyboard was also featured in my Differences between and classifications of 122-key Model Ms comparison topic.

Original specs/details

Full Name Affirmative Computer Products 5250 Emulation Keyboard
Part NumberPart Number
The number used to describe this keyboard's specific release; usually specific for a target region, language or SKU, etc.
Market Model Name/Feature CodeMarket Model Name/Feature Code
The consumer-friendly model number describing this keyboard as a part of a range of products, usually irrespective of target region, language or SKU.
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 M Type IV 122-key Emulator Converged 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.
The name of the known switching mechanism that lies under this keyboard's keys.
IBM membrane 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.
Single-setting elongated flip-out feet
The protocol(s) this keyboard can use to speak to the host computer (eg, scancode sets).
IBM scancode set 2
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.
Black coiled-style fixed PS/2 mini-DIN cable
Form FactorForm Factor
The standardised or universally acknowledged name for this keyboard's layout form factor.
Production Date 2005-03-28
Acquisition Date 2020-10-05

About this keyboard type

The Type IV 122-key Model M Function Key Keyboard is a version of the Type III designed to be natively compatible with PCs to serve in terminal emulation roles. Officially called the IBM Personal System/2 Host Connected Keyboard, Type IVs were relatively rare but for a long time were the only 122-key Model Ms easily capable of modern usage until Soarer's Converter became widespread. Visually, Type IVs look like Type IIIs except all IBM-branded versions had lock-light LEDs as standard and come with modular SDL connections capable of accepting an AT or PS/2 plug cable. IBM also started a practice producing Type IVs under third-party branding to companies that offer terminal emulation services, which Unicomp continues to do to this day. Unicomp also produces a version of the Type IV for consumer usage called the Unicomp PC-122. Like the Type IIIs, the 24-key function key block was only labelled with an "Fxx" nomenclature.