The "Beamfoot" - 1981 IBM 528X-83 type Model B keyboard

IBM 5281/5282/5285/5286 Data Station Typewriter Keyboard (P/N 2658984)

Quick summary:

• 528X-83 type Model B keyboard
• 83-key Italian layout
• IBM beam spring clicky key-switches
• Double-shot SAN keycaps
• Made by IBM Italia
• Some call this the "beamfoot" as it resembles the later IBM 5291/5292 Model F keyboard but in Model B form
• The speaker present was likely used to simulate what a solenoid did for other Model B keyboards or provide audible cues from the system

That's a lot of numbers in the name... I hear you. This is what I call a 528X-83 type Model B keyboard! 528x family, 83 keys. I call it so because the habit of calling most IBM Model B(eamspring) keyboards by simply "5281", "5251", "3276", etc. isn't really accurate, in my opinion and experience. As per the cable tab from the speaker, this keyboard must've been made in the first half of 1981.

The IBM 5280 Distributed Data System was announced in January 1980 and was a 'diskette-based system' for distributed processing and data entry. There were several data stations within the family:

• IBM 5281 Data Station
• IBM 5282 Dual Data Station
• IBM 5285 Programmable Data Stationn
• IBM 5286 Dual Programmable Data Station

The stations themselves resembled the more common 5250 series terminals such as the 5251 and 5252. 5281 and 5285 were single-operator stations, 5282 and 5286 were dual-operator stations. 5285 and 5286 were additionally "programmable" stations. My understanding is that thee dual-operator ones had a single CRT inside that's optically split to either user. A 66-key data entry version of this keyboard also exists.