Purpose of a "mystery key" on an IBM PC 3270 keyboardA colleague has just come into possession of a large number of IBM PC 3270 keyboards (don't ask!). These keyboards have a number of very interesting looking keys, but the one that most intrigued us is the one at the bottom right of the block illustrated here:
In the absence of knowing its purpose, we've nicknamed it the "person in a wheelchair being chased down a hill by a boulder" key. We are relatively confident, however, that this isn't its actual name.
Any PC/mainframe history buffs able to help us out?
ACCEPTED]
I do know the symbol on the bottom right key as being the symbol typically used when proofreading written documents. It is a delete. When you write that over a letter or word in a paper, it indicates that it is unneeded and should be removed. Seeing as how this is an older keyboard, the users of the equipment at the time likely would be very familiar with proofreading symbols and understand what it represents.
My guess (without having used the machine in question) is that it likely is the delete key.
This page [1] goes through a history of some IBM keyboard layouts, and a few pages down you see this image:
You can see the key layout in your screenshot above the arrow keys. The key layout is:
Dup/PA1 FM/PA2 PA3
Back Tab Insert Delete
The delete mark on the key makes sense, especially combined with the proof-reading mark also used for "insert".
[1] http://www.quadibloc.com/comp/kyb03.htma) or symbol (°). ° is on the first symbol from the top-left on German keyboards, on the key directly below Esc. - u17
This is an IBM 6110344 keyboard [1] and the keys on the 6110344 are laid out like this:
So the key you're looking for corresponds to scan code "6D". When we look at the related scan codes on the link given above, that key turns out to be Del, namely Delete.
The symbol you nick named as 'person in wheelchair being chased down a hill by a boulder' is for indicating that the alphabet is wrong.
Closely looking at the key we can separate the a and the other symbol .
The other symbol is indicating wrong sign.
something like we use for right 
& wrong 
. This symbol is shown in slightly different angle indicating strike off the alphabet (or delete the alphabet).
a° with a /... - Tamara Wijsman
(a/°) is the DEL key. At its left is the INSERT key (â).
It does look like a proofreading notation. A letter with a bar crossing it out and a circle. Refer to delete in this page:
[1]https://people.sunyit.edu/~russ/Com310/ProofreadSymbols.pdf
That's funny, because, in Unicode, there is a symbol for insert (⎀) but I never found it used. Here, â seems really near the "insert" function (but, ô tempora ô mores, too strange for European users), so the strange symbol seems to mean "delete".
Check out the first item in this list: http://wadsworth.com/english_d/templates/student_resources/1413001890_burnett/UsageHandbook/edit_marks.htm
It's supposed to be the old fashioned delete symbol. You may remember this symbol from elementary school, but I guess most people have probably never seen it. Myself, I haven't hand-written a school paper since at least 5th grade (1997ish), so it's been quite a while.
The sound of typing on this thing is oddly satisfying to me.
About the mystery key(s):
https://grammarist.com/editing/proofreading-editing-marks-symbols/
This is the keyboard for an IBM 3290 Plasma display (Perhaps a specific model - I don't remember.). That's the zoom key. The display could be configured as 1 LU or 4 tiled LU's on the screen. The zoom key zoomed into the active tiled LU, filling the large screen. Our operators loved the big single screen!
I configured a number of 3274's to work as 4 LU's. Some of the business guys used the display to view a printed page at 160 columns, 50(?) rows.
IIRC, the top symbol was also the letter "a" - the same as the bottom symbol but smaller. Maybe it was scratched off. It was intended to indicate zooming!
I never saw an application which used the PA3 key either!
