https://en.wikipedia.org/wiki/IBM_3270
IBM 3270 - Wikipedia
ibm 3270wikipedia
https://www.ibm.com/docs/en/ims/15.6.0?topic=system-using-programmed-symbols-3270
IMS 15.6 - Operations and automation - Using programmed symbols for IBM 3270
Programmed Symbols (PS), an optional feature on the IBM 3270 terminal, lets you store and access up to six character sets of 190 characters each that are...
15 6