ZMACS overstrike mode?

[Doug Evans <DE@phoenix.sch.symbolics.com>]

    Date: Thu, 3 Nov 88 07:49:11 pst
    From: ragosa%psyche@BOEING.COM (Rich Ragosa - BH AI Center - (215)
	  591-4295)

    I'd like to be able to set ZMACS in overstrike mode. Is this
    possible?

This is easy, as long as you avoid one major pitfall.

Overstrike mode is entered with m-X Overwrite Mode <RETURN>

You can get out of this mode by doing the above command
again.  It acts like a toggle for the mode.

Unfortunately, only character insert commands are changed.
The <RUB OUT> key will give you alot of trouble if you use
it in this mode.  Typing <RUB OUT> while in Overwrite Mode
will cause you to lose the character positions for the
characters being rubbed out.  This makes it impossible to
put your corrections in without typing over correct text.

Instead of using RUBOUT, you should use a keyboard macro to
redefine the <BACK SPACE> key to be more useful and use it
instead.  You can define the macro manually with the
keystrokes:

	c-X (                      ; Begin a keyboard macro
	c-B                        ; Backspace one character
	c-X )                      ; End the keyboard macro
	m-X Install Macro <RETURN> ; put the macro on a key
	<RETURN>                   ; Take default of last macro defined
	<BACK SPACE>               ; Put it on the <BACK SPACE> key
	J <RETURN>                 ; Use this macro Just In This Editor

Or you can have the macro defined by a lisp form and
installed in a ZMACS command table file:

1;;; -*- Mode: LISP; Package: ZWEI -*-

;;; this put the ZMACS function ZWEI:COM-BACKWARD onto the BACKSPACE KEY
0(set-comtab *standard-comtab* '(#\backspace com-backward))

1;;; End of file

0This way REUBOUT will work properly in normal insert mode,
while BACKSPACE will work properly in Overwrite Mode.