comment
   Preserve file channel #0 (the console) while declaring channels
   #2 and #3 as sequential-access ASCII files.
end
files d, sa, sa
var s = string:255
based errcode = integer
base errcode at 103H

comment
   CP/M expects upper case file names, but S-BASIC does not
   automatically convert file name arguments to upper case, so we
   have to do that ourself.
end
create "OUTPUT.TXT"
open #1,"INPUT.TXT"
open #2,"OUTPUT.TXT"

comment
   S-BASIC allows alphanumeric line "numbers" (which are treated simply
   as labels) as the target of GOTO and GOSUB statements, but the first
   character must be a digit
end
on error goto 9done

rem - runtime error code 15 signals read past end of file
while errcode <> 15 do
  begin
    input3 #1; s
    print #2; s
  end

9done
close #1
close #2

end