ERA ;in: A=01h, [IX+0]=ptr to "filename"
REN ;in: A=02h, [IX+0]=ptr to "newname",[IX+2]=to "oldname"
CPM loads the boot sector from Drive A, Track 0, Side 0, Sector 41h to 0100h..02FFh, and starts it (entrypoint=0100h). DIR displays the directory (similar to CAT, but without alphabetically sorted names, and optionally allowing to specify a filename with "*" and "?" wildcards). ERA erase a file (or multiple files with wildcards). REN renames are a file.
== DISC/TAPE.IN/.OUT ==