Wikipedia
IND$FILE
IND$FILE is a file transfer program from IBM that was first released in 1983 to allow the transfer of files between an IBM PC running the IBM 3270 emulator (PC/3270) and a VSE, MVS or VM/CMS mainframe. IND$FILE originally worked only with the SEND and RECEIVE commands of the 3270 PC emulator, but today most terminal emulators that have a 3270 mode include it.