* s/template.h: Explain the relative significance of the SIGIO and

	INTERRUPT_INPUT macros.

diff --git a/src/s/template.h b/src/s/template.h
index aab7d735d84176eca76b6ae3f01bd703eb8874c1..b7abe09e449afe98c3802c2d1922e6aa4082b08f 100644 (file)
--- a/src/s/template.h
+++ b/src/s/template.h
@@ -50,8 +50,13 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
 /* Emacs can read input using SIGIO and buffering characters itself,
    or using CBREAK mode and making C-g cause SIGINT.
    The choice is controlled by the variable interrupt_input.
+
    Define INTERRUPT_INPUT to make interrupt_input = 1 the default (use SIGIO)
 
+   Emacs uses the presence or absence of the SIGIO macro to indicate
+   whether or not signal-driven I/O is possible.  It uses
+   INTERRUPT_INPUT to decide whether to use it by default.
+
    SIGIO can be used only on systems that implement it (4.2 and 4.3).
    CBREAK mode has two disadvatages
      1) At least in 4.2, it is impossible to handle the Meta key properly.
@@ -62,8 +67,7 @@ the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
    Another method of doing input is planned but not implemented.
    It would have Emacs fork off a separate process
    to read the input and send it to the true Emacs process
-   through a pipe.
-*/
+   through a pipe. */
 
 #define INTERRUPT_INPUT