											VARMINT'S AUDIO TOOLS Information
														 VERSION 0.61  (beta)

											Sound Blaster programming library

														 Eric Jorgensen 1995

													 - Ground Up Software -
DISCLAIMER

	This software and documentation is provided as-is and is not
	garanteed to do or be anything.  Blah blah blah. Use at your own risk.

INTRODUCTION

	Varmint's Audio Tools (VAT) is a small, full-featured Sound Blaster 
	programming Kit. It's primary feature is a DSP interrupt driven core that 
	handles real-time mixing and playing of digital sounds, background MIDI
	music, and background MOD music.   It supports many FM chip routines, 
	input functions for WAVE samples, MIDI music files, and MOD music files, 
	true MPU-401 MIDI output, auto recognition and setup of Sound Blaster 
	compatable cards, millisecond clock and microsecond-accuracy timers. 
	VAT is Freeware and comes with example code.

	The inspiration for VAT came from Peter Sprenger's library called SOUNDX.  
	Special thanks go to Peter for writing the first sound library that I
	could get to work on my computer.

SO WHO NEEDS IT?

	VAT is intended for any DOS programmer who wants to add sound effects
	and music to their programs quickly and easily.
	
	Like so many other programmers, I've been very dissappointed by the
	sound library offerings out there.  I have designed VAT to be very easy
	to use and as versatile as possible, and I hope that it is useful to you.

PERFORMANCE ISSUES

	When dealing with routines that run in the background, most programmers
	are concerned about how many CPU processing cycles the routines use up.  
	Here are the numbers that I get on my 486 DX2/66:

	Base overhead:  2.8 %
	Midi overhead:  1.0 % (average)
	Sample overhead: 1.0% per sample
	MOD overhead: 6% (per active channel)

	So, let's say that your program is playing some midi music and 4 digital
	samples in the background.  The total overhead would be: 2.8% (base) +
	1% (midi) + 4 * 1.0% (samples) = 7.8%.  That means that
	if you were animating some graphics at 30 FPS, it would slow down to
	27 FPS.  Pretty acceptable, especially considering that these numbers
	can be improved with compiler optimizations.


FEATURES

	- Background DMA digital playback with real time mixing and
		unlimited channels.
	- Variable speed playback and volume control of individual sounds.
	- Background Playing of MIDI music with easy control of tempo and volume.
	- Background Playing of MOD music with easy control of tempo and volume.
	- Routines to access the FM chip.
	- MPU-401 true MIDI output.
	- MPU and FM patchmap support.   Includes 128 FM instrument patches.
	- Vertical retrace-checking-functions for animators.
	- Millisecond (adjustable) clock plus microsecond accuracy timers.
	- Auto recognition and setup of Sound Blaster or Sound Blaster
		compatable sound cards.
	- Does not disturb the system clock (does not use int08)
	- Comes with heavily commented demo and example code.

BETA VERSION

	BETA means bugs.  I am trying very hard to get rid of bugs in
	VAT, but this is especially tricky when I am trying to get it to 
	work with so many Sound Blaster configurations on so many platforms.
	I am relying heavily on people like you to try out VAT and report
	any problems.  Please help me make this a great tool!  If the demo
	crashes on your computer, please run VAT with -debug in the command line.
	This will dump extra information to the survey.txt file that will
	help me to figure out what is wrong.

HOW TO CONTACT THE AUTHOR

	Any suggestions or bug reports are very welcome.  (The demo program
	creates the file "survey.txt" to make this process easier you.) Please 
	send them to one of these email addresses:

						smeagol@rt66.com
						ejorgensen@rr5.intel.com

FREEWARE (LISCENCING)

	VAT is freeware, so you are free to copy and distribute this library
	as much as you like as long as you charge no fee for it's distribution.
	(The exception to this is if VAT is distributed as part of a large
	collection of shareware/freeware packages.) You are NOT restricted, 
	however, from charging money for games or other programs that use 
	VAT to produce sound.  All I ask is that you send me a complimentary 
	copy.   This helps me as a developer to know who is using my software 
	and for what.  It is also a good way to make friends!

	In other words:

		Q: Can I put any of the programs or example code from VAT into my
			 own shareware library that I am going to sell for money?

		A: Absolutely not.

		Q: If I use VAT to generate sounds in my game, can I sell my game
			 for money?

		A: Yes!  (Please send Eric Jorgensen a complimentary copy of your game!)

WHAT HAPPENED TO THE SOURCE CODE?

	This sound library has grown to be quite a large project.  I recently 
	helped form a game programming group called "Ground Up", and since then, 
	we have pooled our efforts into VAT.  Most notably, Bryan Wilkins has 
	done a great job in porting VAT to protected mode.  As a result, 
	the code is now owned largely by _Ground Up_, and we have decided as 
	a group to hold on to the source.  I realize that this may be annoying to
	many people, especially after I have been giving away the source up until
	now.  I aplogize for the inconvenience, and I want you to know that I am
	still committed to producing a high-quality, easy-to-use product that
	is affordable by everyone. If you are still upset, then I ask: 
	What do you want for nothing?

GROUND UP SOFTWARE

	Varmint's Audio Tools is now  production of _Ground Up_.  We are just a 
	fledgeling group and this is our first product, but we hope to put out 
	several more utilities and games in the near future. Members:

	Neil Breeden    (nbreeden@swcp.com)
	Daniel Hust   (drhust@tesuque.cs.sandia.gov)
	Eric Jorgensen  (smeagol@rt66.com)
	Bryan Wilkins   (bwilkins@swcp.com)

VARMINT'S HOME FTP SITE

	I have a home site for all of my software:

			mack.rt66.com:/users/smeagol

	Here you can find my other shareware and freeware offerings:

		tmkr11.zip          Terrain Maker - A random Terrain generator/
												editor for the freeware raytracer Persistence
												of Vision (POV).  Shareware.

		vpova10.zip          Varmint's POV animator - A POV scene file parser
												that allows the inclusion of functions and
												animation commands.  Freeware.

		svgaccft.zip        50 fonts for SVGACC.   Freeware.

		svgadiag.zip        SVGA diagnostic utility.  Freeware.

		survey_results.txt  Compiled results of a large survey of SVGA cards
												that I performed in December of 1994.





