PROGRAM:  Quixx
AUTHOR:   Jonathan Kraidin on 2/90
VERSION:  1.5 on 11/90
USE:      TSR Screen Animator
REQUIRES: DOS 3.0 or above (might work with 2.1 and above, but not tested)
	  CGA, EGA, VGA
	  192K of Expanded memory strongly recommended
SOURCE:   ASSEMBLY


USE:      This is a TSR program that generates a beautiful selection of vapor-
like trails after a given idle period.  A simple help file can be called by 
typing QUIXX ? at the DOS prompt.  The program is loaded into memory with:
QUIXX TimeOut Mode

where TimeOut is the idle time in minutes (1 to 99) and Mode is from
0 to 19.  Modes 1 through 15 select a constant color display for the QUIXX using
a color palatte corresponding to the Mode.  That is Mode 2 = color 2.

Mode 0 selects an alternating color display.  Every time the Quixx pattern 
bounces off of a wall the color increments.  Mode 16 selects a pattern where
the colors vary within each line of the Quixx pattern.  This yields a constantly
changing image as the vapor trail moves.  Mode 17 selects the same pattern-type,
but in VGA mode19, allowing 256 colors.  The resolution is 320x200.  Mode
18 is also in VGA mode19, but here the lines of the vapor trail are solid.  As
a new lines are drawn they go go through all 256 colors.  

Mode 19 is the Glide mode.  Here the Quixx pattern is one color, 
but as the image moves its color goes through a continuous spectrum of 384
shades.

The options can be changed at any time by retyping the command.  So if you had
typed:

QUIXX 2 15

selecting a 2 minute time-out using mode 15, and you then type

QUIXX 5

you change the timeout to 5 minutes and leave the mode unchanged.  If you typed

QUIXX 5 19

you will have also changed the mode to mode 19.

If you wish to unload the TSR type

QUIXX r

This will Remove the TSR from the TSR memory chain, regardless of the number
of TSRs loaded before or after the QUIXX program.

IT IS STRONLY RECOMMENDED THAT YOU HAVE EXPANDED MEMORY to prevent memory 
conflicts when the TSR saves your video screen.  While the program will use
higher memory without EXPANDED memory, the program may crash your system
depending on what applications are running.  This program has worked well using
Expanded Memory with programs like WordPerfect and Harvard Graphics.

The program also has a 'speed' sensing algorithm to adjust the speed of the 
program to the speed of the computer.

The assembly source is available on request.  It is several pages long and
includes four modules: 

1. TSR and DOS interface routines
2. QUIXX animation routines
3. Graphics routines/Expaned memory routines
4. Command line routines

The code is well commented in most parts and can teach the reader about:

.non-reentrant TSRs
.unloading TSRs
.accessing Video Memory/saving/restoring
.using Expanded Memory
.writing graphics algorithms
.reading/writing directly to the CGA/EGA/VGA graphics registers

The program is free to use, copy, and distribute.  The source is only $5
and well worth it.  If interested write to:

Jonathan Kraidin
3301 Indian Queen Lane
Philadelphia, PA  19129

CIS 72576, 2122
 
worth it.  If int