Yn.zip -
It was designed for CP/M , an operating system that preceded MS-DOS and was widely used on microcomputers in the late 70s and early 80s.
In the era of bulletin board systems (BBS) and early computing, "YN" stood for , a recursive naming convention popular among programmers (similar to YACC—Yet Another Compiler-Compiler). yn.zip
The file typically contained the 8080 assembly source code for a modem communication program. It was designed for CP/M , an operating