Basic Gravis UltraSound Programming
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� GUSDOC �
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THE OFFICAL
GRAVIS ULTRASOUND PROGRAMMERS ENCYCLOPEDIA
( G.U.P.E )
v 0.1
Written by Mark Dixon.
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
INTRODUCTION
~~~~~~~~~~~~
The Gravis Ultrasound is by far the best & easiest sound card to
program. Why? Because the card does all the hard stuff for you, leaving
you and the CPU to do other things! This reference will document some
(but not all) of the Gravis Ultrasound's hardware functions, allowing
you to play music & sound effects on your GUS.
We will not be going into great detail as to the theory behind
everything - if you want to get technical information then read the
GUS SDK. We will be merely providing you with the routines necessary
to play samples on the GUS, and a basic explanation of how they work.
This document will NOT go into DMA transfer or MIDI specifications.
If someone knows something about them, and would like to write some
info on them, we would appreciate it very much.
All source code is in Pascal (tested under Turbo Pascal v7.0, but
should work with TP 6.0 and possibly older versions). This document
will assume reasonable knowledge of programming, and some knowledge of
soundcards & music.
INITIALISATION & AUTODETECTION
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Since we are not using DMA, we only need to find the GUS's I/O port,
which can be done from the DOS environment space, or preferably from a
routine that will scan all possible I/O ports until it finds a GUS.
The theory behind the detection routine is to store some values into
GUS memory, and then read them back. If we have the I/O port correct,
we will read back exactly what we wrote. So first, we need a routine
that will write data to the memory of the GUS :
Function GUSPeek(Loc : Longint) : Byte;
{ Read a value from GUS memory }
Var
B : Byte;
AddLo : Word;
AddHi : Byte;
Begin
AddLo := Loc AND $FFFF;
AddHi := LongInt(Loc AND $FF0000) SHR 16;
Port [Base+$103] := $43;
Portw[Base+$104] := AddLo;
Port [Base+$103] := $44;
Port [Base+$105] := AddHi;
B := Port[Base+$107];
GUSPeek := B;
End;
Procedure GUSPoke(Loc : Longint; B : Byte);
{ Write a value into GUS memory }
Var
AddLo : Word;
AddHi : Byte;
Begin
AddLo := Loc AND $FFFF;
AddHi := LongInt(Loc AND $FF0000) SHR 16;
Port [Base+$103] := $43;
Portw[Base+$104] := AddLo;
Port [Base+$103] := $44;
Port [Base+$105] := AddHi;
Port [Base+$107] := B;
End;
Since the GUS can have up to 1meg of memory, we need to use a 32bit
word to address all possible memory locations. However, the hardware of
the GUS will only accept a 24bit word, which means we have to change
the 32bit address into a 24bit address. The first two lines of each
procedure does exactly that.
The rest of the procedures simply send commands and data out through
the GUS I/O port defined by the variable BASE (A word). So to test for
the presence of the GUS, we simply write a routine to read/write memory
for all possible values of BASE :
Function GUSProbe : Boolean;
{ Returns TRUE if there is a GUS at I/O address BASE }
Var
B : Byte;
Begin
Port [Base+$103] := $4C;
Port [Base+$105] := 0;
GUSDelay;
GUSDelay;
Port [Base+$103] := $4C;
Port [Base+$105] := 1;
GUSPoke(0, $AA);
GUSPoke($100, $55);
B := GUSPeek(0);
If B = $AA then GUSProbe := True else GUSProbe := False;
End;
Procedure GUSFind;
{ Search all possible I/O addresses for the GUS }
Var
I : Word;
Begin
for I := 1 to 8 do
Begin
Base := $200 + I*$10;
If GUSProbe then I := 8;
End;
If Base < $280 then
Write('Found your GUS at ', Base, ' ');
End;
The above routines will obviously need to be customised for your own
use - for example, setting a boolean flag to TRUE if you find a GUS,
rather than just displaying a message.
It is also a good idea to find out exactly how much RAM is on the
GUS, and this can be done in a similar process to the above routine.
Since the memory can either be 256k, 512k, 768k or 1024k, all we have
to do is to read/write values on the boundaries of these memory
addresses. If we read the same value as we wrote, then we know exactly
how much memory is available.
Function GUSFindMem : Longint;
{ Returns how much RAM is available on the GUS }
Var
I : Longint;
B : Byte;
Begin
GUSPoke($40000, $AA);
If GUSPeek($40000) <> $AA then I := $3FFFF
else
Begin
GUSPoke($80000, $AA);
If GUSPeek($80000) <> $AA then I := $8FFFF
else
Begin
GUSPoke($C0000, $AA);
If GUSPeek($C0000) <> $AA then I := $CFFFF
else I := $FFFFF;
End;
End;
GUSFindMem := I;
End;
Now that we know where the GUS is, and how much memory it has, we
need to initialise it for output. Unfortunately, the below routine is
slightly buggy. If you run certain programs (I discovered this after
running Second Reality demo) that use the GUS, and then your program
using this init routine, it will not initialise the GUS correctly.
It appears that I am not doing everything that is necessary to
initialise the GUS. However, I managed to correct the problem by
either re-booting (not a brilliant solution) or running Dual Module
Player, which seems to initialise it properly. If someone knows where
i'm going wrong, please say so!
Anyway, the following routine should be called after you have found
the GUS, and before you start doing anything else with the GUS.
Procedure GUSDelay; Assembler;
{ Pause for approx. 7 cycles. }
ASM
mov dx, 0300h
in al, dx
in al, dx
in al, dx
in al, dx
in al, dx
in al, dx
in al, dx
End;
Procedure GUSReset;
{ An incomplete routine to initialise the GUS for output. }
Begin
port [Base+$103] := $4C;
port [Base+$105] := 1;
GUSDelay;
port [Base+$103] := $4C;
port [Base+$105] := 7;
port [Base+$103] := $0E;
port [Base+$105] := (14 OR $0C0);
End;
Now you have all the routine necessary to find and initialise the
GUS, let's see just what we can get the GUS to do!
MAKING SOUNDS
~~~~~~~~~~~~~
The GUS is unique in that it allows you to store the data to be
played in it's onboard DRAM. To play the sample, you then tell it what
frequency to play it at, what volume and pan position, and which sample
to play. The GUS will then do everything in the background, it will
interpolate the data to give an effective 44khz (or less, depending on
how many active voices) sample. This means that an 8khz sample will
sound better on the GUS than most other cards, since the GUS will play
it at 44khz!
The GUS also has 32 seperate digital channels (that are mixed by a
processor on the GUS) which all have their own individual samples,
frequencies, volumes and panning positions. For some reason, however,
the GUS can only maintain 44khz output with 16 channels - the more
channels, the lower the playback rate (which basically means, lower
quality). If you are using all 32 channels (unlikely), then playback is
reduced to 22khz.
Since you allready know how to store samples in the GUS dram (simply
use the GUSPoke routine to store the bytes) we will now look at various
routines to change the way the gus plays a sample. The first routine we
will look at will set the volume of an individual channel :
Procedure GUSSetVolume( Voi : Byte; Vol : Word);
{ Set the volume of channel VOI to Vol, a 16bit logarithmic scale
volume value - 0 is off, $ffff is full volume, $e0000 is half
volume, etc }
Begin
Port [Base+$102] := Voi;
Port [Base+$102] := Voi;
Port [Base+$102] := Voi;
Port [Base+$103] := 9;
Portw[Base+$104] := Vol; { 0-0ffffh, log scale not linear }
End;
The volume (and pan position & frequency) can be changed at ANY time
regardless of weather the GUS is allready playing the sample or not.
This means that to fade out a sample, you simply make several calls to
the GUSSetVolume routine with exponentially (to account for the
logarithmic scale) decreasing values.
The next two routines will set the pan position (from 0 to 15, 0
being left, 15 right and 7 middle) and the frequency respectively :
Procedure GUSSetBalance( V, B : Byte);
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $C;
Port [Base+$105] := B;
End;
Procedure GUSSetFreq( V : Byte; F : Word);
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := 1;
Portw[Base+$104] := F;
End;
I'm not sure the the value F in the set frequency procedure. The GUS
SDK claims that it is the exact frequency at which the sample should be
played.
When playing a sample, it is necessary to set the volume, position
and frequency BEFORE playing the sample. In order to start playing a
sample, you need to tell the GUS where abouts in memory the sample is
stored, and how big the sample is :
Procedure GUSPlayVoice( V, Mode : Byte;VBegin, VStart, VEnd : Longint);
{ This routine tells the GUS to play a sample commencing at VBegin,
starting at location VStart, and stopping at VEnd }
Var
GUS_Register : Word;
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $0A;
Portw[Base+$104] := (VBegin SHR 7) AND 8191;
Port [Base+$103] := $0B;
Portw[Base+$104] := (VBegin AND $127) SHL 8;
Port [Base+$103] := $02;
Portw[Base+$104] := (VStart SHR 7) AND 8191;
Port [Base+$103] := $03;
Portw[Base+$104] := (VStart AND $127) SHL 8;
Port [Base+$103] := $04;
Portw[Base+$104] := ((VEnd) SHR 7) AND 8191;
Port [Base+$103] := $05;
Portw[Base+$104] := ((VEnd) AND $127) SHL 8;
Port [Base+$103] := $0;
Port [Base+$105] := Mode;
{ The below part isn't mentioned as necessary, but the card won't
play anything without it! }
Port[Base] := 1;
Port[Base+$103] := $4C;
Port[Base+$105] := 3;
end;
There are a few important things to note about this routine. Firstly,
the value VEnd refers to the location in memory, not the length of the
sample. So if the sample commenced at location 1000, and was 5000 bytes
long, the VEnd would be 6000 if you wanted the sample to play to the
end. VBegin and VStart are two weird values, one of them defines the
start of the sample, and the other defines where abouts to actually
start playing. I'm not sure why both are needed, since I have allways
set them to the same value.
Now that the gus is buisy playing a sample, the CPU is totally free
to be doing other things. We might, for example, want to spy on the gus
and see where it is currently up to in playing the sample :
Function VoicePos( V : Byte) : Longint;
Var
P : Longint;
Temp0, Temp1 : Word;
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $8A;
Temp0 := Portw[Base+$104];
Port [Base+$103] := $8B;
Temp1 := Portw[Base+$104];
VoicePos := (Temp0 SHL 7)+ (Temp1 SHR 8);
End;
This routine will return the memory location that the channel V is
currently playing. If the GUS has reached the end of the sample, then
the returned value will be VEnd. If you want to see what BYTE value is
currently being played (for visual output of the sample's waveform),
then you simply PEEK the location pointed to by this routine.
Finally, we might want to stop playing the sample before it has
reached it's end - the following routine will halt the playback on
channel V.
Procedure GUSStopVoice( V : Byte);
Var
Temp : Byte;
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $80;
Temp := Port[Base+$105];
Port [Base+$103] := 0;
Port [Base+$105] := (Temp AND $df) OR 3;
GUSDelay;
Port [Base+$103] := 0;
Port [Base+$105] := (Temp AND $df) OR 3;
End;
SPECIAL EFFECTS
~~~~~~~~~~~~~~~
There are a few extra features of the GUS that are worthy of mention,
the main one being hardware controlled sample looping. The GUS has a
control byte for each of the 32 channels. This control byte consists of
8 flags that effect the way the sample is played, as follows :
( The table is taken directly from the GUS Software Developers Kit )
=================================
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
=================================
| | | | | | | |
| | | | | | | +---- Voice Stopped
| | | | | | +-------- Stop Voice
| | | | | +------------ 16 bit data
| | | | +---------------- Loop enable
| | | +-------------------- Bi-directional loop enable
| | +------------------------ Wave table IRQ
| +---------------------------- Direction of movement
+-------------------------------- IRQ pending
(*)Bit 0 = 1 : Voice is stopped. This gets set by hitting the end
address (not looping) or by setting bit 1 in this reg.
Bit 1 = 1 : Stop Voice. Manually force voice to stop.
Bit 2 = 1 : 16 bit wave data, 0 = 8 bit data
Bit 3 = 1 : Loop to begin address when it hits the end address.
Bit 4 = 1 : Bi-directional looping enabled
Bit 5 = 1 : Enable wavetable IRQ. Generate an irq when the voice
hits the end address. Will generate irq even if looping
is enabled.
(*)Bit 6 = 1 - Decreasing addresses, 0 = increasing addresses. It is
self-modifying because it might shift directions when
it hits one of the loop boundaries and looping is enabled.
(*)Bit 7 = 1 - Wavetable IRQ pending. If IRQ's are enabled and
looping is NOT enabled, an IRQ will be constantly
generated until voice is stopped. This means that
you may get more than 1 IRQ if it isn't handled
properly.
Procedure GUSVoiceControl( V, B : Byte);
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $0;
Port [Base+$105] := B;
End;
The above routine will set the Voice Control byte for the channel
defined in V. For example, if you want channel 1 to play the sample in
a continuous loop, you would use the procedure like this :
GUSVoiceControl( 1, $F ); { Bit 3 ON = $F }
CONCLUSION
~~~~~~~~~~
The above routines are all that is necessary to get the GUS to start
playing music. To prove this, I have included my 669 player & source
code in the package as a practical example. The GUSUnit contains all
the routines discussed above. I won't go into the theory of the 669
player, but it is a good starting point if you want to learn about
modplayers. The player is contained within the archive 669UNIT.ARJ
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� README �
읕컴컴컴켸
GUS669 Unit v0.2b
Copyright 1994 Mark Dixon.
(aka C.D. of Silicon Logic)
LEGAL STUFF
~~~~~~~~~~~
I'd like to avoid this, but it has to be done. Basically, if anything
in this archive causes any kind of damage, I cannot be held
responsable - USE AT YOUR OWN RISK.
In adition, since I spent long hours working on this project, and
attempting to decode the GUS SDK, I would appreciate it if people
didn't rip off my work. Give me credit for what I have done, and if
your planning to use my routines for commercial purposes, talk to me
first, or you might find yourself on the wrong side of a legal battle.
(Hey, let's sound tough while i'm at it, I have lawyer's in the
family, so it's not gonna cost me much to sue someone. And don't
criticise my spelling! :)
BORING STUFF
~~~~~~~~~~~~
Well, if your the sort of person who likes to ignore all the rubishy
bits that go into a README text file, then you'd better stop now and
go and try out the source code!
Basically, this readme isn't going to say much more than what the
source code is, and then go dribling on for five pages about
absolutely nothing.
SOURCE CODE! DID SOMEONE SAY - SOURCE CODE!! - ????
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Yes, that's right, free with every download of this wonderful archive
comes the complete Pascal source code to a 669 module player for the
GUS. I'd have included my MOD player, but I haven't been able to get
all the MOD commands working, so you'll just have to make do with a
669 player :)
Feel free to make use of this source code for any non-commercial
purposes you might be able to think of - and mention my name while
your at it! Since the source code is here, people are bound to modify
it for their personal uses. If you do this, I would very much like to
see your modifications - so that I can include them in the next
release of the player.
Well, I don't want to bore you anymore, and it's getting late (not!)
so i'd better let you go and play around with the source code :)
SILICON LOGIC
~~~~~~~~~~~~~
What ever happened to Silicon Logic? Well, after being killed off over
in Perth, a major revival is underway here in Canberra, with a more
commercial view - more on that later.
For those of you who have never heard of Silicon Logic, then you're
either not Australian, or not into the ausie demo scene. But then,
that covers about 99.999999999999% of the world population :)
GREETINGS
~~~~~~~~~
I've allways wanted to dribble some thanks, so here goes.
Thanks go to...
Darren Lyon - Who got me into this programming lark in the first
place. Finally wrote myself a mod player :)
Tran - Your source code really helped!
Kitsune - Love those mods, keep up the good work!
... and Advanced Gravis, for making the best sound card ever.
Greetings to...
FiRE members - I'll probably never join you guys, but good luck
anyway!
UNiQUE - How's the board going?
CRaSH - Still ripping other peoples source code?
Old SL members - Thanks for the support, good luck with your new
group!
Oliver White - G'day... just thought i'd say hi, since you so
kindly beta tested the player for me.
Murray Head - Rick Price sux! :-) SoundBlaster sux too! :-)
Perth people - I'm coming back... someday!
THE PICK / MINNOW - Hey, give me a call sometime, long time no
talk...
INTERESTED IN A DEMO GROUP IN CANBERRA?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If there is anyone interested in joining a demo / coding group in
Canberra (ACT), then drop me a line.
旼컴컴컴컴컴컫컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�
� GUSUNIT.PAS�
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Unit GUSUnit;
{
GUS DigiUnit v1.0
Copyright 1994 Mark Dixon.
This product is "Learnware".
All contents of this archive, including source and executables, are the
intellectual property of the author, Mark Dixon. Use of this product for
commercial programs, or commercial gain in ANY way, is illegal. Private
use, or non-commercial use (such as demos, PD games, etc) is allowed,
provided you give credit to the author for these routines.
Feel free to make any modifications to these routines, but I would
appreciate it if you sent me these modifications, so that I can include
them in the next version of the Gus669 Unit.
If you wish to use these routines for commercial purposes, then you will
need a special agreement. Please contact me, Mark Dixon, and we can work
something out.
What's "Learnware"? Well, I think I just made it up actually. What i'm
getting at is that the source code is provided for LEARNING purposes only.
I'd get really angry if someone ripped off my work and tried to make out
that they wrote a mod player.
As of this release (Gus699 Unit), the Gus DigiUnit has moved to version
1.0, and left the beta stage. I feel these routines are fairly sound,
and I haven't made any changes to them in weeks.
Notice the complete absence of comments here? Well, that's partially
the fault of Gravis and their SDK, since it was so hard to follow, I
was more worried about getting it working than commenting it. No offense
to Gravis though, since they created this wonderful card! :-) It helps
a lot if you have the SDK as a reference when you read this code,
otherwise you might as well not bother reading it.
}
INTERFACE
Procedure GUSPoke(Loc : Longint; B : Byte);
Function GUSPeek(Loc : Longint) : Byte;
Procedure GUSSetFreq( V : Byte; F : Word);
Procedure GUSSetBalance( V, B : Byte);
Procedure GUSSetVolume( Voi : Byte; Vol : Word);
Procedure GUSPlayVoice( V, Mode : Byte;VBegin, VStart, VEnd : Longint);
Procedure GUSVoiceControl( V, B : Byte);
Procedure GUSReset;
Function VoicePos( V : Byte) : Longint;
Const
Base : Word = $200;
Mode : Byte = 0;
IMPLEMENTATION
Uses Crt;
Function Hex( W : Word) : String;
Var
I, J : Word;
S : String;
C : Char;
Const
H : Array[0..15] of Char = ('0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F');
Begin
S := '';
S := S + H[(W DIV $1000) MOD 16];
S := S + H[(W DIV $100 ) MOD 16];
S := S + H[(W DIV $10 ) MOD 16];
S := S + H[(W DIV $1 ) MOD 16];
Hex := S+'h';
End;
Procedure GUSDelay; Assembler;
ASM
mov dx, 0300h
in al, dx
in al, dx
in al, dx
in al, dx
in al, dx
in al, dx
in al, dx
End;
Function VoicePos( V : Byte) : Longint;
Var
P : Longint;
I, Temp0, Temp1 : Word;
Begin
Port [Base+$102] := V;
Port [Base+$103] := $8A;
Temp0 := Portw[Base+$104];
Port [Base+$103] := $8B;
Temp1 := Portw[Base+$104];
VoicePos := (Temp0 SHL 7)+ (Temp1 SHR 8);
For I := 1 to 10 do GusDelay;
End;
Function GUSPeek(Loc : Longint) : Byte;
Var
B : Byte;
AddLo : Word;
AddHi : Byte;
Begin
AddLo := Loc AND $FFFF;
AddHi := LongInt(Loc AND $FF0000) SHR 16;
Port [Base+$103] := $43;
Portw[Base+$104] := AddLo;
Port [Base+$103] := $44;
Port [Base+$105] := AddHi;
B := Port[Base+$107];
GUSPeek := B;
End;
Procedure GUSPoke(Loc : Longint; B : Byte);
Var
AddLo : Word;
AddHi : Byte;
Begin
AddLo := Loc AND $FFFF;
AddHi := LongInt(Loc AND $FF0000) SHR 16;
{ Write('POKE HI :', AddHi:5, ' LO : ', AddLo:5, ' ');}
Port [Base+$103] := $43;
Portw[Base+$104] := AddLo;
Port [Base+$103] := $44;
Port [Base+$105] := AddHi;
Port [Base+$107] := B;
{ Writeln(B:3);}
End;
Function GUSProbe : Boolean;
Var
B : Byte;
Begin
Port [Base+$103] := $4C;
Port [Base+$105] := 0;
GUSDelay;
GUSDelay;
Port [Base+$103] := $4C;
Port [Base+$105] := 1;
GUSPoke(0, $AA);
GUSPoke($100, $55);
B := GUSPeek(0);
{ Port [Base+$103] := $4C;
Port [Base+$105] := 0;}
{ Above bit disabled since it appears to prevent the GUS from accessing
it's memory correctly.. in some bizare way.... }
If B = $AA then GUSProbe := True else GUSProbe := False;
End;
Procedure GUSFind;
Var
I : Word;
Begin
for I := 1 to 8 do
Begin
Base := $200 + I*$10;
If GUSProbe then I := 8;
End;
If Base < $280 then
Write('Found your GUS at ', Hex(Base), ' ');
End;
Function GUSFindMem : Longint;
{ Returns how much RAM is available on the GUS }
Var
I : Longint;
B : Byte;
Begin
GUSPoke($40000, $AA);
If GUSPeek($40000) <> $AA then I := $3FFFF
else
Begin
GUSPoke($80000, $AA);
If GUSPeek($80000) <> $AA then I := $8FFFF
else
Begin
GUSPoke($C0000, $AA);
If GUSPeek($C0000) <> $AA then I := $CFFFF
else I := $FFFFF;
End;
End;
GUSFindMem := I;
End;
Procedure GUSSetFreq( V : Byte; F : Word);
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := 1;
Portw[Base+$104] := (F { DIV 19}); { actual frequency / 19.0579083837 }
End;
Procedure GUSVoiceControl( V, B : Byte);
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $0;
Port [Base+$105] := B;
End;
Procedure GUSSetBalance( V, B : Byte);
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $C;
Port [Base+$105] := B;
End;
Procedure GUSSetVolume( Voi : Byte; Vol : Word);
Begin
Port [Base+$102] := Voi;
Port [Base+$102] := Voi;
Port [Base+$102] := Voi;
Port [Base+$103] := 9;
Portw[Base+$104] := Vol; { 0-0ffffh, log ... not linear }
End;
Procedure GUSSetLoopMode( V : Byte);
Var
Temp : Byte;
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $80;
Temp := Port[Base+$105];
Port [Base+$103] := 0;
Port [Base+$105] := (Temp AND $E7) OR Mode;
End;
Procedure GUSStopVoice( V : Byte);
Var
Temp : Byte;
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $80;
Temp := Port[Base+$105];
Port [Base+$103] := 0;
Port [Base+$105] := (Temp AND $df) OR 3;
GUSDelay;
Port [Base+$103] := 0;
Port [Base+$105] := (Temp AND $df) OR 3;
End;
Procedure GUSPlayVoice( V, Mode : Byte;VBegin, VStart, VEnd : Longint);
Var
GUS_Register : Word;
Begin
Port [Base+$102] := V;
Port [Base+$102] := V;
Port [Base+$103] := $0A;
Portw[Base+$104] := (VBegin SHR 7) AND 8191;
Port [Base+$103] := $0B;
Portw[Base+$104] := (VBegin AND $127) SHL 8;
Port [Base+$103] := $02;
Portw[Base+$104] := (VStart SHR 7) AND 8191;
Port [Base+$103] := $03;
Portw[Base+$104] := (VStart AND $127) SHL 8;
Port [Base+$103] := $04;
Portw[Base+$104] := ((VEnd) SHR 7) AND 8191;
Port [Base+$103] := $05;
Portw[Base+$104] := ((VEnd) AND $127) SHL 8;
Port [Base+$103] := $0;
Port [Base+$105] := Mode;
{ The below part isn't mentioned as necessary, but the card won't
play anything without it! }
Port[Base] := 1;
Port[Base+$103] := $4C;
Port[Base+$105] := 3;
end;
Procedure GUSReset;
Begin
port [Base+$103] := $4C;
port [Base+$105] := 1;
GUSDelay;
port [Base+$103] := $4C;
port [Base+$105] := 7;
port [Base+$103] := $0E;
port [Base+$105] := (14 OR $0C0);
End;
Var
I : Longint;
F : File;
Buf : Array[1..20000] of Byte;
S : Word;
Begin
Clrscr;
Writeln('GUS DigiUnit V1.0');
Writeln('Copyright 1994 Mark Dixon.');
Writeln;
GUSFind;
Writeln('with ', GUSFindMem, ' bytes onboard.');
Writeln;
GUSReset;
End.
旼컴컴컴컴컴컫컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�
� GUS669.PAS �
읕컴컴컴컴컴켸
UNIT Gus669;
{
GUS669 Unit v0.2b
Copyright 1994 Mark Dixon.
This product is "Learnware".
All contents of this archive, including source and executables, are the
intellectual property of the author, Mark Dixon. Use of this product for
commercial programs, or commercial gain in ANY way, is illegal. Private
use, or non-commercial use (such as demos, PD games, etc) is allowed,
provided you give credit to the author for these routines.
Feel free to make any modifications to these routines, but I would
appreciate it if you sent me these modifications, so that I can include
them in the next version of the Gus669 Unit.
If you wish to use these routines for commercial purposes, then you will
need a special agreement. Please contact me, Mark Dixon, and we can work
something out.
What's "Learnware"? Well, I think I just made it up actually. What i'm
getting at is that the source code is provided for LEARNING purposes only.
I'd get really angry if someone ripped off my work and tried to make out
that they wrote a mod player.
Beta version? Yes, since the product is still slightly unstable, I feel
it is right to keep it under beta status until I find and fix a few
bugs.
FEATURES
- Only works with the GUS!
- 8 channel, 669 music format.
- That's about it really.
- Oh, 100% Pascal high level source code = NO ASSEMBLER!
(So if you want to learn about how to write your own MOD player, this
should make it easier for you)
- Tested & compiled with Turbo Pascal v7.0
BUGS
- Not yet, give me a chance!
(If you find any, I would very much appreciate it if you could take
the time to notify me)
- Doesn't sound right with some modules, advice anyone??
- Could do with some better I/O handling routines when loading the
669 to give better feedback to the user about what went wrong
if the module didn't load.
You can contact me at any of the following :
FidoNet : Mark Dixon 3:620/243
ItnerNet : markd@cairo.anu.edu.au ( prefered )
d9404616@karajan.anu.edu.au ( might not work for mail :) )
sdixonmj@cc.curtin.edu.au ( Don't use this one often )
sdixonmj01@cc.curtin.edu.au ( Might not exist any more,
that's how often it's used! )
I collect internet accounts.... :)
If you happen to live in the Australian Capital Territory, you can
call me on 231-2000, but at respectable hours please.
"Want more comments? Write em!"
Sorry, I just had to quote that. I'm not in the mood for writing lots
of comments just yet. The main reason for writing it in Pascal is so
that it would be easy to understand. Comments may (or may not) come later
on.
Okay, enough of me dribbling, here's the source your after!
}
Interface
Procedure Load669(N : String);
Procedure PlayMusic;
Procedure StopMusic;
Type
{ This is so that we can keep a record of what each channel is
currently doing, so that we can inc/dec the Frequency or volume,
or pan left/right, etc }
Channel_Type = Record
Vol : Word;
Freq : Word;
Pan : Byte;
End;
Var
Channels : Array[1..8] of Channel_Type;
Flags : Array[0..15] of Byte;
{ Programmer flags. This will be explained when it is fully implemented. }
Const
Loaded : Boolean = False; { Is a module loaded? }
Playing : Boolean = False; { Is a module playing? }
WaitState : Boolean = False; { Set to TRUE whenever a new note is played }
{ Helpful for timing in with the player }
Const
NumChannels = 8;
{ Thanks to Tran for releasing the Hell demo source code, from which
I managed to find these very helpfull volume and frequency value
tables, without which this player would not have worked! }
voltbl : Array[0..15] of Byte =
( $004,$0a0,$0b0,$0c0,$0c8,$0d0,$0d8,$0e0,
$0e4,$0e8,$0ec,$0f1,$0f4,$0f6,$0fa,$0ff);
freqtbl : Array[1..60] of Word = (
56,59,62,66,70,74,79,83,88,94,99,105,
112,118,125,133,141,149,158,167,177,188,199,211,
224,237,251,266,282,299,317,335,355,377,399,423,
448,475,503,532,564,598,634,671,711,754,798,846,
896,950,1006,1065,1129,1197,1268,1343,1423,1508,1597,1692 );
Type
Header_669_Type = Record
Marker : Word;
Title : Array[1..108] of Char;
NOS, { No of Samples 0 - 64 }
NOP : Byte; { No of Patterns 0 - 128 }
LoopOrder : Byte;
Order : Array[0..127] of Byte;
Tempo : Array[0..127] of Byte;
Break : Array[0..127] of Byte;
End;
Sample_Type = Record
FileName : Array[1..13] of Char;
Length : Longint;
LoopStart : Longint;
LoopLen : Longint;
End;
Sample_Pointer = ^Sample_Type;
Note_Type = Record
Info, { <- Don't worry about this little bit here }
Note,
Sample,
Volume,
Command,
Data : Byte;
End;
Event_Type = Array[1..8] of Note_Type;
Pattern_Type = Array[0..63] of Event_Type;
Pattern_Pointer = ^Pattern_Type;
Var
Header : Header_669_Type;
Samples : Array[0..64] of Sample_Pointer;
Patterns : Array[0..128] of Pattern_Pointer;
GusTable : Array[0..64] of Longint;
GusPos : Longint;
Speed : Byte;
Count : Word;
OldTimer : Procedure;
CurrentPat, CurrentEvent : Byte;
Implementation
Uses Dos, Crt, GUSUnit;
Procedure Load669(N : String);
Var
F : File;
I, J, K : Byte;
T : Array[1..8,1..3] of Byte;
Procedure LoadSample(No, Size : Longint);
Var
Buf : Array[1..1024] of Byte;
I : Longint;
J, K : Integer;
Begin
GusTable[No] := GusPos;
I := Size;
While I > 1024 do
Begin
BlockRead(F, Buf, SizeOf(Buf), J);
For K := 1 to J do GusPoke(GusPos+K-1, Buf[K] XOR 127);
Dec(I, J);
Inc(GusPos, J);
End;
BlockRead(F, Buf, I, J);
For K := 1 to J do GusPoke(GusPos+K-1, Buf[K] XOR 127);
Inc(GusPos, J);
End;
Begin
{$I-}
Assign(F, N);
Reset(F, 1);
BlockRead(F, Header, SizeOf(Header));
If Header.Marker = $6669 then
Begin
For I := 1 to Header.NOS do
Begin
New(Samples[I-1]);
BlockRead(F, Samples[I-1]^, SizeOf(Samples[I-1]^));
End;
For I := 0 to Header.NOP-1 do
Begin
New(Patterns[I]);
For J := 0 to 63 do
Begin
BlockRead(F, T, SizeOf(T));
For K := 1 to 8 do
Begin
Patterns[I]^[J,K].Info := t[K,1];
Patterns[I]^[J,K].Note := ( t[K,1] shr 2);
Patterns[I]^[J,K].Sample := ((t[K,1] AND 3) SHL 4) + (t[K,2] SHR 4);
Patterns[I]^[J,K].Volume := ( t[K,2] AND 15);
Patterns[I]^[J,K].Command := ( t[K,3] shr 4);
Patterns[I]^[J,K].Data := ( t[K,3] AND 15);
End;
End;
End;
For I := 1 to Header.NOS do
LoadSample(I-1, Samples[I-1]^.Length);
End;
Close(F);
{$I+}
If (IOResult <> 0) OR (Header.Marker <> $6669) then
Loaded := False else Loaded := True;
End;
Procedure UpDateNotes;
Var
I : Word;
Inst : Byte;
Note : Word;
Begin
WaitState := True;
For I := 1 to NumChannels do
With Patterns[Header.Order[CurrentPat]]^[CurrentEvent, I] do
For I := 1 to NumChannels do
If (Patterns[Header.Order[CurrentPat]]^[CurrentEvent, I].Info < $FE) then
Begin
Inst := Patterns[Header.Order[CurrentPat]]^[CurrentEvent, I].Sample;
Note := Patterns[Header.Order[CurrentPat]]^[CurrentEvent, I].Note;
Channels[I].Freq := FreqTbl[Note];
{ Channels[I].Pan := (1-(I AND 1)) * 15;}
Channels[I].Vol := $100*VolTbl[Patterns[Header.Order[CurrentPat]]^[CurrentEvent, I].Volume];
{ Write(Note:3,Inst:3,' -');}
GUSSetVolume (I, 0);
GUSVoiceControl (I, 1);
GUSSetBalance (I, Channels[I].Pan);
GusSetFreq ( I, Channels[I].Freq);
{ GUSPlayVoice ( I, 0, GusTable[Inst],
GusTable[Inst],
GusTable[Inst]+Samples[Inst]^.Length );}
{ Write(Samples[Inst]^.LoopLen:5);}
If Samples[Inst]^.LoopLen < 1048575 then
Begin
GUSPlayVoice ( I, 8, GusTable[Inst],
GusTable[Inst]+Samples[Inst]^.LoopStart,
GusTable[Inst]+Samples[Inst]^.LoopLen );
End
Else
Begin
GUSPlayVoice ( I, 0, GusTable[Inst],
GusTable[Inst],
GusTable[Inst]+Samples[Inst]^.Length );
End;
End;
{ Writeln;}
For I := 1 to NumChannels do
If (Patterns[Header.Order[CurrentPat]]^[CurrentEvent, I].Info < $FF) then
GUSSetVolume (I, $100*VolTbl[Patterns[Header.Order[CurrentPat]]^[CurrentEvent, I].Volume]);
For I := 1 to NumChannels do
With Patterns[Header.Order[CurrentPat]]^[CurrentEvent, I] do
Case Command of
5 : Speed := Data;
3 : Begin
Channels[I].Freq := Channels[I].Freq + 10;
GUSSetFreq(I, Channels[I].Freq);
End;
8 : Inc(Flags[Data]);
6 : Case Data of
0 : If Channels[I].Pan > 0 then
Begin
Dec(Channels[I].Pan);
GusSetBalance(I, Channels[I].Pan);
End;
1 : If Channels[I].Pan < 15 then
Begin
Inc(Channels[I].Pan);
GusSetBalance(I, Channels[I].Pan);
End;
End;
End;
Inc(CurrentEvent);
If CurrentEvent > Header.Break[CurrentPat] then Begin CurrentEvent := 0; Inc(CurrentPat) End;
If Header.Order[CurrentPat] > (Header.NOP) then Begin CurrentEvent := 0; CurrentPat := 0; End;
End;
Procedure UpDateEffects;
Var
I : Word;
Begin
For I := 1 to 4 do
With Patterns[Header.Order[CurrentPat]]^[CurrentEvent, I] do
Begin
Case Command of
0 : Begin
Inc(Channels[I].Freq, Data);
GusSetFreq(I, Channels[I].Freq);
End;
1 : Begin
Dec(Channels[I].Freq, Data);
GusSetFreq(I, Channels[I].Freq);
End;
End;
End;
End;
{ $ F+,S-,W-}
Procedure ModInterrupt; Interrupt;
Begin
Inc(Count);
If Count = Speed then
Begin
UpDateNotes;
Count := 0;
End;
UpDateEffects;
If (Count MOD 27) = 1 then
Begin
inline ($9C);
OldTimer;
End;
Port[$20] := $20;
End;
{ $ F-,S+}
Procedure TimerSpeedup(Speed : Word);
Begin
Port[$43] := $36;
Port[$40] := Lo(Speed);
Port[$40] := Hi(Speed);
end;
Procedure PlayMusic;
Begin
If Loaded then
Begin
TimerSpeedUp( (1192755 DIV 32));
GetIntVec($8, Addr(OldTimer));
SetIntVec($8, Addr(ModInterrupt));
Speed := Header.Tempo[0];
Playing := True;
End
{ If the module is not loaded, then the Playing flag will not be set,
so your program should check the playing flag just after calling
PlayMusic to see if everything was okay. }
End;
Procedure StopMusic;
Var
I : Byte;
Begin
If Playing then
Begin
SetIntVec($8, Addr(OldTimer));
For I := 1 to NumChannels do GusSetVolume(I, 0);
End;
TimerSpeedUp($FFFF);
End;
Procedure Init;
Var
I : Byte;
Begin
GusPos := 1;
Count := 0;
Speed := 6;
CurrentPat := 0;
CurrentEvent := 0;
For I := 1 to NumChannels do Channels[I].Pan := (1-(I AND 1)) * 15;
For I := 1 to NumChannels do GUSVoiceControl(I, 1);
For I := 0 to 15 do Flags[I] := 0;
End;
Var
I, J : Byte;
Begin
Init;
Writeln('GUS669 Unit V0.2b');
Writeln('Copyright 1994 Mark Dixon.');
Writeln;
End.
旼컴컴컴컴컴컴쩡컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�
� PLAY669.PAS �
읕컴컴컴컴컴컴�
Program Testout_Gus669_Unit;
Uses Crt, GUS669;
Begin
If ParamCount > 0 then Load669(Paramstr(1))
else
Begin
Writeln;
Writeln('Please specify the name of the 669 module you wish to play');
Writeln('from the command line.');
Writeln;
Writeln('eg : Play669 Hardwired.669 ');
Writeln;
Halt(1);
End;
PlayMusic;
If Playing then
Begin
Writeln('Playing ', ParamStr(1) );
Writeln('Press any key to stop and return to DOS.');
Repeat
Until Keypressed
End
else
Begin
Writeln;
Writeln('Couldn''t load or play the module for some reason!');
Writeln;
Writeln('Please check your GUS is working correctly, and that you have');
Writeln('correctly specified the 669 filename.');
Writeln;
End;
StopMusic;
End.
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