


                                  ROLLBACK

                  Copyright (c) S&B Enterprises, 1992,1993


INTRODUCTION

    This utility will automatically capture information displayed on your
screen and allow you to re-display it long after it has scrolled off the
screen.  For example if you type the DIR command in DOS and part of your
directory scrolls off the top of your screen, you can press a 'hot-key' to
scroll that information back onto your screen.  The output from any DOS
programs and commands that use the standard DOS and/or BIOS calls will be
automatically captured and re-displayed at your request.
    If you find this program useful, please register for the commercial
version of ROLLBACK which will allow you to scroll back up to 60 screens,
change screen colors, and more.


INSTALLATION

    ROLLBACK is a TSR. To make it automatically available every time you start
your computer, you will want to add a line to your AUTOEXEC.BAT.  For example:

   ROLLBACK 
     or
   ROLLBACK [/K%%] [/V] [/P]     
  
     Switches:  /K%% := Sets the Hot-Key that activates ROLLBACK as follows:
                    /KPU for ALT+Page_Up (this is the default).
                    /KUP for ALT+Up_arrow.
                    /KSP for ALT+Spacebar.
                    /KPD for ALT+Page_down.
                    /KDN for ALT+Down arrow.

                /V   := Allows ROLLMONO to work on color video cards.

                /P   := Changes previous settings without asking.
  
    For example, to install ROLLBACK using the ALT+Spacebar as the hot-key,
you would add the following line to your AUTOEXEC.BAT file:

   ROLLBACK /KSP /P

    If you have a monochrome video card, use the ROLLMONO program instead of
ROLLBACK with the same switch option as above.





USAGE

    You activate ROLLBACK by pressing the hot-key (ALT+PageUp by default). 
The screen changes color and a title bar appears at the bottom of the screen. 
You can now use the following keys to scroll back through past information: UP
and DOWN arrow keys, PageUp and PageDown, HOME (top) and END (bottom).  The
ESC key will exit from ROLLBACK and return you to your original screen and
your original colors.  The CTRL-Z key will allow you to exit from ROLLBACK
without restoring your original screen (leaving the currently viewed past
screen on your display).  Any other key will cause you to exit from ROLLBACK
and the key you hit will be passed on to DOS.


COMPATIBILITY

    ROLLBACK works well in all CGA, EGA, and VGA text modes (eg: 40 col. by 25
lines through 132 col. by 54 lines.  It even works in some graphics modes (eg:
600 by 350 resolution).  If you try a graphics mode that is not supported,
ROLLBACK will warn you by beeping.  The installation routine detects the type
of display adapter card you have in your computer.  If you have a monochrome,
text-only (no graphics) card, the installation routine will install a special
non-paging version call ROLLMONO.
    Some programs do not use the standard DOS and BIOS routines to display
information on the screen.  Information that these programs display will not
be captured and cannot be re-displayed.  Some programs use the standard
routines in an inconsistent way that causes some information to be captured,
but not all.  For example, if an editor program only uses the standard
routines to display the current line number, and uses direct screen writing
to display the text, then ROLLBACK will only capture the line numbers.  Some
ANSI.SYS display drivers can intercept or add to the characters that are
captured.  For example, the ANSI.SYS that comes with DOS 5.0 re-displays the
first character of each line redundantly several times.  This causes the
captured information to appear with a few extra characters and blank lines.  
    ROLLBACK gives you several choices for a 'hot-key' so you can select a key
that is meaningful to you and one that does not conflict with some other 'hot-
key' that you might already be using for something else.



REGISTRATION

    This program is Shareware.  You are welcome to copy and distribute this
software in its entirety (unmodified).  If you find this software useful,
please send $15 to register and receive the latest commercial version to:

              S&B Enterprises
              P.O. Box 3407
              Vista, CA 92083

Please indicate diskette size.
Schools and businesses are encouraged to contact us regarding multiple copy
discounts.  Commented Assembly and PASCAL source code for the commercial
version is also available.  