rem --  Set the logged drive ('A' to 'P')
procedure setdrive (drive = char)
   var hl, de, bc, a_psw = integer
   rem -- ensure drive letter is upper case
   if drive >= 'a' then drive = drive - 32
   hl = 0
   de = drive - 65
   bc = 0EH  rem BDOS set drive function
   a_psw = 0
   rem - call BDOS with drive number in DE
   call (5H,hl,de,bc,a_psw)
end

rem  -- Set the CP/M user area (0 to 15)
procedure setuser (user = integer)
   var hl, bc, a_psw = integer
   hl = 0
   bc = 20H  rem BDOS set user function
   a_psw = 0
   rem - call BDOS with user number in DE
   call (5H,hl,user,bc,a_psw)
end

comment
   create empty file "output.txt" in current directory and in
   startup directory (drive A:, user 0)
end

create "OUTPUT.TXT"
setdrive 'A'
setuser 0
create "OUTPUT.TXT"

end