STOS MAESTRO INSTRUCTIONS
STOS MAESTRO INSTRUCTIONS
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ
Complete DOCS typed for Sewer Software by Paul.
Brought to you by Sewer Software.
Note : These DOCS are huge (over 100K) so make sure your printer
is feeling pretty good and you've got a bit of spare time
before attempting to print the entire docs. But then again,
if you've got that much spare time, why don't you write us
some docs and send them to the address in the scrolltext.
CONTENTS
--------
Introduction................................................... 1
Connecting the STOS maestro cartridge to an ST............... 1
Making a backup.............................................. 2
What is a sampler............................................ 3
Chapter 1: The sound sampler editor............................ 5
Loading and playing a sample................................. 5
The main screen.............................................. 6
Spectrum analysers and pointers......................... 6
Sample display area..................................... 7
Play and record area.................................... 7
The menu bar........................................... 10
Cut and paste....................................... 10
Disc options........................................ 11
FX menu............................................. 13
Special options..................................... 14
Creating your own welcome sample............................ 15
Chapter 2: Disco and Phaser programmes........................ 16
STOS Maestro Disco unit..................................... 16
STOS Phaser programme....................................... 17
Chapter 3: STOS Basic Interface............................... 17
Installing the new STOS Maestro extension file.............. 18
Maestro accessory........................................... 18
Accessory tutorial.......................................... 19
Drum machine................................................ 20
Chapter 4: STOS Maestro commands.............................. 21
Playback commands........................................... 21
Sampler control commands.................................... 29
Chapter 5: Creating your own sampler in STOS Basic............ 30
Initialisation.............................................. 30
Setting the sample speed.................................... 31
Recording a sample.......................................... 31
Playing a sample............................................ 32
through the loudspeaker................................ 32
Chapter 6: Technical appendix................................. 33
Adding sampled sounds to an existing STOS Basic programme... 35
Assembly language interface................................. 36
STOS Maestro Plus cartridge specifications.................. 38
INTRODUCTION
------------
Congratulations for buying STOS Maestro, an exciting new utility which,
together with the STOS Compiler, continues Mandarin's commitment to support
STOS Basic.
STOS Maestro allows you to incorporate "real" sounds of professional
quality - speech, music and special effects - into your STOS Basic programmes
with the addition of only a few lines of code. Not only will it enhance the
style and quality of your games and programmes but is also a fun package to
use.
The package is available in two formats: STOS Maestro and STOS Maestro
Plus. The only difference is that the latter package includes the
professionally-designed sampler cartridge.
With the STOS Maestro Plus sampler cartridge you can record your sounds as
easily as you would play a record or cassette and the whole world of sound is
open to you. To get you started, the STOS Maestro package contains over 50
sampled sounds, along with the two discs - one containing the programmes, the
other containing the samples. You will also find a registration card and
details about the STOS Maestro Plus sampler cartridge and how to order it -if
you don't already have one.
Connecting the STOS maestro plus sampler cartridge to an ST
-----------------------------------------------------------
If your STOS Maestro set up includes the sampler cartridge you must follow
the steps below. They detail the proper use of the cartridge.
1 Before inserting or removing the cartridge turn the ST off. Otherwise the
cartridge or even the computer could develop a fault.
2 Insert the cartridge into the ST's cartridge port (located on the left side
of the system), taking care to ensure that the STOS Maestro sticker is
facing up and facing towards you.
3 Now insert the STOS Maestro programmes disc into drive A and turn on the
ST.
External lead requirements
--------------------------
The cartridge links the ST to the outside world of sound. You must now
connect an external sound source to the cartridge.
We have supplied a female phono port to which you must connect an external
lead. For best results take the output from the headphones port of your
external source (hi-fi, tape recorder, walkman, musical keyboard). This
output can be controlled via the volume control. If you directly transfer the
sound from, say, a CD by phono to phono then you'll probably find the sound
output is too high and won't be controllable. If you don't have such a lead
then any electronic shop will be able to supply you with one - if you're
unsure, take the cartridge with you and explain your requirements to the
shopkeeper.
On the enclosed samples disc are 51 sampled sounds. Here's a quick list for
your reference.
-------------------------------------------------------------------------
| Synthesiser sounds Voices |
| ------------------ ------ |
| 5th string violin Bonus points |
| Clockwork EEEEERRRRR... |
| Easy synth Level |
| Fullrank 1, 2, 3, 4, 5 |
| Moonsynth Game over |
| Orchestra H-e-l-p! |
| Piano brass Get ready |
| Pitch bend |
| Spacy sound Sound effects |
| Synth Bass ------------- |
| Weird sound Boing |
| Yeah sound Bounce |
| Computer bleep |
| Musical Instruments Electric door |
| ------------------- Explosion |
| Acoustic guitar Helicopter rotor blades |
| Electric guitar Laugh |
| Gong Laser gun |
| Horn Machine gun |
| Orchestral stab Metal bar sound |
| Panpipe Pistol shot |
| Piano Siren |
| Saxophone Smashing |
| Strings Spring effect |
| Tubular bells Swoosh |
| Zangy |
-------------------------------------------------------------------------
Making a backup
---------------
Stos Maestro is not copy-protected which means you can make backups or load
it onto a hard drive if you have one. But please don't give copies to other
people. STOS Maestro took many months to produce and it is only by continuing
sales that we will able develop new extension discs and accessory programmes.
The two STOS Maestro discs have been specially formatted so as to fit the
extra music demos on. This means that side two of each disc cannot be copied
using the standard Gem Desktop backup procedure. Don't worry about this
because copying the discs as single format will backup the other files - it's
only the DEMO.TOS files that can't be re-duplicated. If you have a special
copying utility such as PROCOPY then you'll be able to back the discs up
fully. The following procedure shows how you should backup the discs as
single sided.
1 Slide the write protect tab of the original disc so that you can see
through the hole. This will guard your disc against possible mistakes during
copying.
2 Place a blank disc into drive A and format it as single sided
3 Now put the STOS Maestro programme disc into drive A and drag the drive A
icon on to the drive B icon.
4 Follow the prompts displayed in the Gem dialogue boxes.
5 Repeat steps 1 to 4 for the STOS Maestro samples disc.
You will now be left with two backup discs, but the DEMO.TOS files won't
work.
As you read through the manual and experiment with the samples, you may
well create some new sounds which you really like. Keep a spare formatted
disc to hand for storing your samples but don't you worry if you forget - the
STOS Maestro editor has a built in disc formatter.
What is a sampler?
------------------
You probably know that sampled sounds are extremely realistic - they are, in
fact "real" sounds - and most ST games make a feature of the life-like music
and sound effects they contain. But how does the sound get inside the
computer in the first place?
Here's the theory behind sampling - but don't worry, there's not much of it
and it won't hurt a bit. If you know how sampling works you'll get much more
out of the programme.
If you really don't want to know what's going on you can memorise the
following simple rule and skip ahead to Chapter 1: The higher the sampling
rate the better the sound quality but the more memory it will take.
Simply, sampling is the process of converting analogue sound into digital
information, storing it in the computer and then converting it back to
analogue sound again so we can hear it. The routines required to do this are
known, naturally enough, as analogue-to-digital and digital-to-analogue
converters or A-to-D and D-to-A for short. These terms you will come across
whenever samplers are mentioned.
STOS Maestro does all this conversion work for you automatically so you
don't have to worry about it at all. But it will help in understand a little
about the mechanics of the conversion process.
If you look at sound waves on an oscilloscope you'll see that they consist
of lots of smooth curves and continuously varying lines. Computers, as you
probably know, aren't very good with curves. At their lowest level they can
only store the digits 0 and 1 and when they draw a curve on the monitor
you'll notice that it's not a continuous unbroken line but a series of steps,
generally pixel size.
So how can we represent a continuously varying value (sound waves) as
numbers? THe solution is to take samples of the sound wave at regular
intervals and store the reading as numbers.
Let's put this little bit of theory into practice and see what happens when
we sample a sine wave, the purest sound in the universe, it's a little like a
plain flat whistle or flute sound and does not contain any "other noises"
(the technical term for these is harmonics) which make a sound bright and
raspy like brass, thin and reedy like an oboe or hollow like a clarinet (sine
in Latin means "without").
If you feed a sine wave into an oscilloscope the display will appear
something like this:
--------------------------------------
| |
| |
| |
| |
| paste figure 1 here |
| |
| |
| |
| |
--------------------------------------
It tells us that the entire sine wave lasted only four milliseconds (four
thousandths of a second). Or to put it another way, 250 of these sine waves
will occur every second. The actual pitch produced by this will be an out-of-
tune B below middle C, but we'll use this value because it makes things
simpler if we stick to round numbers.
How many samples do we need to take to convert to digital form? Let's try
taking a sample once every thousandth of second. We'd get something like
this:
--------------------------------------
| |
| |
| |
| |
| paste figure 2 here |
| |
| |
| |
| |
--------------------------------------
It's a nice try but it's not a very good representation of a sine wave, is
it? Let's increase the sample rate to four thousandths of second:
--------------------------------------
| |
| |
| |
| |
| paste figure 3 here |
| |
| |
| |
| |
--------------------------------------
That's a bit more like it, although it's not quite perfect.
To avoid having to talk in terribly small numbers like so-may thousandths
of a second, we use the term kiloHerz which is abbreviated to KHz. So we can
say our first digital conversion was sampled at 1KHz and the second at 4KHz.
The sampling rate in STOS Maestro can be varied from 5KHz to 32KHz. You can
see that we were getting pretty close to a sine wave with a sample rate of
4KHz.
At 32KHz our digital representation of the wave will be pretty close to the
real thing.
Great! So you could sample everything at 32KHz. Well you could but I've got
some good news and bad news for you.
As we've seen, the more samples taken in a given time, the more accurate
the digital model will be and consequently the better the sound quality will
be on playback, that's the good news.
However the more samples you take in a given time, the more data you
accumulate, the more memory you will require and the more jerkily your STOS
sprites will move because so much processor time is being taken up. That's
the bad news.
You will find that some samples will sound fine at low sample rates but
others will lose their brightness and "edge". Here's the bottom line:
Sampling is a trade off between fidelity and memory used.
But here's some good news. In order to convert digital data into sound,
samplers use a conversion table and the quality of the sample depends upon
the precision and accuracy of this table. Maestro incorporates a super quiet,
high precision conversion table and you'll find that many samples san be
recorded and played back at quite low sampling rates and still sound good.
And here's even more good news - STOS Maestro employs a technique called
oversampling which enables samples to be taken at low sample rates with
greater than average accuracy. It also features a unique pack facility which
lets you squeeze more samples into less memory. Oversampling and pack are
fully explained in chapter 1.
Okay, that's enough theory, now let's get sampling
--------------------------------------------------------------------------
| 1: The Sound Sampler Editor |
--------------------------------------------------------------------------
Quick Start Guide
By now you'll want to see - and hear - what STOS Maestro can do so we'll run
through a few basics to get you up and running.
WARNING: If you are going to create samples of your own with STOS
Maestro Plus sampler cartridge, make sure your Atari ST is switched
off
before plugging the cartridge into the cartridge port
Insert your backup programme disc into the disc drive and turn on your
computer. Double-click on the Drive A icon and a window will open. Double
click on STOSM.PRG
When the loading screen appears, press the 1 key on the ST's keyboard to
load the sampler programme. Alternatively the sampler can be loaded by
double-clicking on the Phaser programmes described later.
Upon loading the display will change to a screen full of icons and a welcome
sample will be played.
Loading and playing a Sample
----------------------------
Remove the STOS Maestro programme disc and place the back-up sample disc in
your drive. To load a sample you must first select the disc menu (we'll
explain all about the various menus in a moment) so click on the disc icon on
the second line from the bottom:
DISC MENU: The Disc menu will roll down on the bottom line. Click on the
leftmost icon and a Gem-type file selector box will appear. You will notice
that the samples have been divided into four types and stored in four
folders: Music, Sound, Synth and Voice.
Open a folder by clicking on the folder name. Then load a sample by double-
clicking on the sample name or by clicking on it to highlight it and then
clicking on the OK box. A message will appear in the middle of the screen
telling you which sample file the programme is loading then you will see a
small blue and white visual representation of the sound to the left of the
central display area. To hear the sample, left click on the Play icon:
PLAY: To stop playback press the spacebar. Whenever the programme is sampling
or playing back you can always halt the operation by pressing the spacebar.
You'll notice that when you do this an orange bar appears in the display area
marking the point at which you stopped playback. This helps pinpoint small
sections of a sound within a larger sample and is useful during editing.
Now that you know how to load and play samples, you can try out some of the
other sounds on the disc. Let's now look at all the exciting features STOS
Maestro has to offer.
The main screen
---------------
STOS Maestro only has one main screen so it's very easy to use. At first
glance some of the icons may look strange but they will be explained in
detail. You will soon master STOS Maestro and using it will quickly become
second nature.
The STOS Maestro screen is divided into four areas.
--------------------------------------
| |
| |
| |
| |
| |
| paste figure 4 here |
| |
| |
| |
| |
| |
--------------------------------------
Options are selected by moving the arrow around the screen with the mouse
and left clicking on an icon. The right button has some special functions
which we'll explain when we come to them.
1 Spectrum analysers, position and size displays
Spectrum analysers: These are the two large boxes in the top left and right
hand corners of the screen. They give a visual representation of the signal
which is entering the Audio-In socket of the STOS Maestro Plus cartridge.
They will work whenever you aren't doing anything which requires the
programmes full attention such as sampling and playing back.
Use the indicators as a guide to the volume level of the signal. They are
calibrated in decibels (dB) which is how sound levels are measured. The more
decibels, the louder the signal.
When you're recording a sample, get as much signal into the programme as
you can but don't turn the volume up so high that the bars hit the top of the
windows and are truncated as this will distort the sample.
Here's a useful tip: When you're recording, try to avoid trailing the lead
which connects the sound source to the cartridge over your computer or
alongside your monitor as it may pick up background noise.
Position and size indicators: Underneath the spectrum analysers are the
position indicators labeled POS1 and POS2. These show which area of memory
you are currently working on and reflect the position of the two white dotted
pointers in the sample display area below.
In between the position indicators is the size indicator which tells you
how much memory (in bytes) lies between the two pointers. This is very
useful: Not only does it save you doing complicated sums but it can tell you
exactly how large a sample is so you know how much memory it will take up in
your STOS programmes.
The total amount of memory will depend on the size of your ST's ram. On a
1040 ST you will have a little less than 700k to play with. We'll look at
this more in detail now.
2 Sample display area
This gives you a visual representation of the sample(s) in memory. Upon
loading the programme, this area will show all the free memory - and it will
be completely empty. The two white dotted lines at either end of the display
area are the pointers. The left mouse button controls the left pointer and
the right mouse button controls the right pointer.
Using the mouse, position the arrow anywhere in the display area and press
the left mouse button. The pointer will move to the arrow position. Move the
arrow to the right and press the right button and the right pointer will do
likewise. Note that the position and size indicators change as you move the
pointers. Also note that the left pointer cannot be further right than the
right pointer, and vice versa.
In addition you can click and drag the pointers around the display area by
keeping the left or right button pressed and moving the mouse.
The area between the pointers is the current work area and all recording,
playing and editing functions take place between these pointers. If you want
to hear just a part of a sample, isolate it with the pointers.
Just below the sample display area is the memory bar indicator. This
indicates how much of the available memory is actually in view in the display
area. It also shows where it lies in relation to the whole of the memory.
This will become clear when we look at the magnify and de-magnify facilities.
At the moment the bar runs the full width of the display area indicating that
the whole of the available memory is on view.
3 The Play and Record area
This consists of the two rows of icons below the sample display area. Let's
look at them one by one.
|<- Moves the left pointer to the extreme left of the sample display area.
<- Moves the left pointer to the left of the display by one pixel. If it is
already at the extreme left of the display area you won't be able to move it
any further. Although the pointer moves one pixel at a time, the actual
number of bytes it steps will vary according to the amount of memory
represented by the display area. On a 1040 ST, if the whole of available
memory is shown in the display area a one-pixel movement will step on by
about 2550 bytes.
-> Moves the left pointer to the right by one pixel. Using these step
functions you can home in accurately on a particular part of a sample. The
right pointer can be controlled with similar icons located at the far right
of this line of icons.
Magnify: This "blows-up" the current work area (that part of memory between
the two pointers) to fill the sample display area. Let's try an experiment.
Load the BONUSPNT.SAM file in the VOICE folder. Move the right pointer a
little to the right of the end of the sample (until the size indicator reads
between 15000 and 16000) and click on the Play icon to check that the whole
sample is between the pointers.
Now click on Magnify. That's more informative, isn't it. Now move the right
pointer so that it's just to the left of the last little "blip" in the
display area. Click on play. You should now have lost the "s" off "points".
It should be easy to see where "Bonus" ends and "Points" begins. Move the
right pointer further left until you only hear "Bonus" when you click on
Play.
Now try something a bit more tricky. See if you can move the right pointer
so that the "Bonus" become "Bone". Fun isn't it?
You can magnify an area, define another area and magnify that and so on
down to a maximum magnification level of about 320 bytes. At this level, the
encapsulated sample will be so short it will be little more than a click.
You cannot magnify more than 15 times. However if you are working on a
specific area of a sample, you will probably find you reach the maximum 320
bytes level after only four or five magnifications.
Watch the memory bar indicator as you magnify. It shows exactly where the
sample sits in relation to the total memory.
De-Magnify: Reverses the magnification process and steps backwards through
the various stages of magnification which have been made. Watch the memory
bar indicator.
Thru: Clicking here turns the mouse pointer from an arrow into a busy bee.
Any sound source fed into the stos Maestro Plus sampler cartridge will now
sound through your monitor as it plays. The quality of the sounds is
determined by the record sample rate (second row, extreme right) - see
later). This allows you to check the quality of a sound before recording it.
Programme: Used to programme the function keys with samples. Click on the
Wipe icon to clear memory and then load the GAMEOVER.SAM sample. Magnify it
and use the right pointer to isolate "Game" - its not where you'll probably
look for it first. Left click on Programme and `the display area will prompt
you to press a function key. Press F1. Right click on Programme, press F1
and you will hear "Game". Unlike normal playback mode you can press the
function key before the sample has finished playing to create the famous "N-
N-N-N-N-Nineteen" effect - or "G-G-G-Game" in this case. Press the spacebar
to escape from playback mode. Now isolator "Over" and store it in F2. If
you accidentally select Programme and don't wish to set a function key then
you can quit by pressing any other key.
Programme doesn't store the actual samples, `rather it keeps a note of the
positions of the left and right pointers. We can demonstrate this easily:
Click on the Full icon (the very next on on our list) and load GETREADY.SAM
Right click on Programme and press F1 and F2.
Full: A useful control which you have already used. It restores the
pointers to the start and end of memory.
Wipe: This wipes (empties) the whole of memory, not just the section between
the pointers (use the Cut function which you'll find in the Edit Menu). its
non reversible and you get a warning prompt before it proceeds. It resets
the pointers to the start and end of available memory.
Play (and Play Menu): Left clicking here plays the sample between the two
pointers. Right clicking will roll down the Play menu on the bottom line.
Load GETREADY.SAM (you may have to click on the disc icon to get the Disc
Menu back). Magnify the sample and move the right pointer pretty close the
end of the sample. Now for some fun: Right click on Play.
Backwards Loop: Play the sample in reverse and loops its. Press spacebar to
stop.
Forwards Loop: Plays the sample forwards and loops it.
Forwards/Backwards Loop: Plays the sample forwards then backwards also in a
loop.
Backwards: Plays the sample backwards once.
Forwards: This is the default Play button and plays the sample forwards.
Notice that as you select each of the icons they appear in the second line in
place of the Play icon. This allows you to use any of these types of
playback during editing without having to call up the Play menu each time.
Playback Rate: If you recall the sampling theory from the introduction,
you'll remember that the more samples we take in a given time, the better the
quality. Its probably occurred to you that you can sample at one rate and
play back at another. If you haven't tried this yet lets try it now. The
principle involved is rather like speeding up or slowing down an audio
recording using a record deck (playing 45s and 33rpm) or a reel-to-reel
recorder. You probably know that if you slow down a recording the pitch
becomes lower and speeding it up produces Pinky and Perky voices.
Its the same with sampling. If you increase the playback speed of a sample
-the rate at which the digital information is passed through the D-to A
converter - the pitch becomes higher, and vice versa. This is easy to do on
a computer. This icon is used to set the playback speed which can be fully
varied from 5KHz to 32 KHz. Click on the left and right arrows to adjust the
rate and check the result by playing the sample. If you double the playback
speed, the pitch of the sample will double. In musical terms it increases by
an octave. If you right click on this icon it will change the playback rate
to that of the record rate.
Playback Plug: This connects the playback routine to the Trigger Level
circuitry.
Trigger Level: This sets the Trigger Level in decibels (we mentioned dBs
briefly in relation to the spectrum analysers). When plugged into the
Playback or Record section of the programme it holds up the function until it
receives an input signal equal to or high than the dB level. When plugged
into a section and activated, the screen will change colour while waiting for
a signal of the correct level. You can escape from this, as usual, by
pressing the spacebar, Check the dB level of incoming signals on the spectrum
analysers.
When recording, the Trigger Level can be useful if you want to record a
sound with silence in front of it.
Record Plug: This connects the Record routine to the Trigger Level
circuitry.
Record: Click here to begin recording will terminate when the current work
area is full Press the spacebar to terminate earlier. Note: Unless the
Trigger is "plugged in". STOS Maestro will begin sampling as soon as Record
is pressed even if there is no sound at the input.
Oversampling: In order to help you make better samples. STOS Maestro uses a
process known as Over-sampling. Its completely automatic and you don't e en
have to switch it in and out.
When STOS Maestro is sampling at 32khz it's running pretty close to flat
out. At lower rates, however, it has a little processing power to spare and
at sampling rates of 19 khz and less it automatically goes into Oversampling
mode.
Instead of sampling at the set rate it takes as many samples as it can
during the sampling time and the works out an average figure. So if you set
the sample rate of 10khz and Maestro oversampled at 50 khz it would take
five samples instead of one average them out. This will provide a more
accurate representation of the sound during that period of time than just one
sample.
Record Rate: This determines the rate in KHz at which the recording is
samples. It works in exactly the same way as the playback rate icon. If you
have the STOS Maestro Plus sampler sampler cartridge, try recording the same
sample at different rates and see how much memory each one uses, then compare
the quality.
4 The Menu Bar
The third line of icons is used to call up various menus onto the bottom
line. You've already used the Play menu and part of the Disc menu.
Cut & Paste Menu: Rolls the Cut & Paste menu onto the bottom line. It
contains a number of tools for manipulating the samples. Load a sample and
try out the various editing procedures.
Play cut buffer: Click here to play the contents of the cut butter. If you
haven't Cut anything yet it will have no effect. Right clicking on this
button allows you to edit any sample currently in the cut buffer. All
operations in the current work area will only affect the cut buffer data.
When you need to return to the full memory sample, simply right click on this
icon again.
Cut: Cuts the area between the two pointers and stores it in the cut buffer.
You can't cut more than 50k of sample (check the size in the size indicator
window) and if you try, a dialogue window will appear advising you of the
fact.
If you haven't done so already, load a sample. Use the right pointer to
isolate it, then magnify it. Now click on Cut and sample will vanish from
the display area. Clicking on Play will have no effect but if you click on
Plays cut buffer you'll hear the sample.
Copy: This is similar to Cut but it copies the area into the cut buffer
leaving the original intact. Again there is a 50k limit on the size of the
area you can copy.
Splice: This cuts out the area between the two pointers and stores it in the
cut buffer. Then it closes up the gap - useful for swapping samples around
memory.
Paste: This copies the contents of the cut buffer into memory starting at
the position of the left pointer. This overwrites any data which may already
be there but the buffer remains intact. If the area between the two pointers
is small than the contents of the cut buffer, the contents of the buffer will
not be copied.
Insert: This is similar to paste but instead of overwriting memory it makes
a space for the buffer contents by moving any data to the right of the
insertion point (the position of the left pointer) further to the right.
It will always insert the full contents of the buffer-any data at the end of
memory will be lost the distance between the left and right pointers dictates
how much of the buffer will be inserted.
Mix: This operation too, begins at the position of the left pointer. It
mixes the contents of the cut buffer with the data which is already there.
This can produce some stunning effects. For example, copy a complete sample
(try one of the voices) into the cut buffer. Move the left pointer a little
to the right and hit Mix. Move it further to the right and Mix again. Make
sure the right pointer is sufficiently far right so it does not truncate the
Mix. Depending upon the offset, this will produce reverb, delay and
variations on the N-N-N-Nineteen effect - or a combination of all three.
Delete: This simply erases the area between the two pointers.
Chop: Erases the sample outside the two pointers and moves the sample
(between the pointers) to the start of free memory.
Flip: This reverses the sample between the two pointers. Playing it will
now have the same effect as clicking on the Play backwards icon in the Play
Menu.
Disc Menu: Rolls down the Disc menu on the bottom line which is where all
file handling takes place. The icons below are available after you click on
the icon.
Load Sample: Produces a Gem file selector box which allows you to load a
file of sample data at the position of the left pointer, allowing you to
store several different samples in memory at the same time. If the memory
area between the left and right pointers is small than the sample then only
this amount will be loaded, so make sure you set them up or use Wipe
beforehand.
On first access, the routine will look for files with the extension SAM.
We recommend you add this extension to all your sample files - but its not
compulsory.
To search for other extensions, click on the path name so that the txt
cursor appears after SAM. Backspace three times to delete SAM and type *
don't press Return because a bug in Gem will send you back to the main
screen.. Instead, click on the top of the file selector box where it says
*.SAM. The directory will now show all files and folders regardless of their
extension. A quick tip is to click on the path name press Escape and then
click on the file selector box top - this default to drive A and uses *.*
search specification.
It's interesting to note that the sample files created by most samplers for
the Atari ST produce the same kind of data. You will be able to load most
samples made with other samplers in Maestro - and vice versa. Even more
interesting is the possibility of grabbing samples from commercial games.
Files of sample data may have the same extension SAM, SPL, SNG, SND or
something else. But beware: Trying to access some protected discs may cause
the STOS Maestro programme lock up.
You may have discovered that you can load any file into STOS Maestro and it
will treat is as sample data. If it's not a sample it will sound terrible -
probably like a screech.
Save sample: This does not prompt for a filename but saves the area between
the pointers with the same name as the last filename used. It will be the
name of the last sample loaded or saved, otherwise it will use the default
SAMPLE.SAM. This is useful as it allows you to work on a sample and save it
quickly without having to type in a filename. If the file already exist on
the disc, a dialogue box will appear requesting permission to update the
file.
A unique STOS Maestro feature means that the playback rate is saved to disc
along with the sample data. You've probably noticed the playback rate change
when loading various samples. No longer will you have to determine the sample
speed by experimentation. However when loading samples from games or created
on other samplers you'll have to find the correct playback rate by trial and
error.
Save sample as: Click here to save the sample between the two pointers. This
option allows you to enter a new filename just as you would with any Gem file
selector.
Insert sample: This works in a similar way to the insert function in the Cut
& Paste menu. It reads a file of sample data from disc and inserts it at the
left pointer position and moves the sample in memory to the right to make
room for it. If you want to combine samples use mix in the Cut & Paste menu.
Drive: Prompts for the current drive. When prompted press a letter from A to
H. The default depends on the drive from which you booted STOS Maestro.
Disc info: Gives information about the current driveL Identifier, total disc
space and total free space.
Delete File: When the file selector appears, click on the file you wish to
delete and then click on OK or just double click on the file. After selecting
a file there is a confirmation prompt so that you can have second thoughts
about this action.
Rename: Use this to rename a file. It can be very useful if you've forgotten
to give a file an extension or if you've a list of samples such as WOW1,
WOW2, WOW3,...WOW16. Click here and the file selector will appear. Select the
file you wish to rename by double clicking on it or by clicking on it once to
highlight it and then clicking on OK. A new file selector box will appear
with the text cursor on the selection heading. Enter a new filename and press
return or click on OK and the file will be renamed. The routine will not
allow you to rename a file with a name that already exists.
Format: Allow you to format a disc as single or double sided without leaving
STOS Maestro. This produces a warning prompt as formatting a disc will erase
all the data on it. Get past this and you are asked to select Drive A or B
and then the number of sides you want to format.
New Folder: Folders are very useful for sorting your samples into types. You
will have noticed that the samples on the data disc are stored in four
folders. Click here and enter the name of the new folder - eight letters
maximum. To escape from this option, press the 'escape' key - a null entry
will also terminate the procedure.
FX: Rolls down the effects menu onto the bottom line. This reveals the four
icons below
Echo: An echo is produced by repeating the original signal after a short
delay. Although the delay is short you will be able to hear the two (or more)
echoes quite distinctly. A characteristic of natural echo is that subsequent
echoes decrease in volume. If you click on Echo with the left button, STOS
Maestro will automatically add echo to the sample between the pointers. This
is irreversible so a dialogue box pops up to warn you. You can repeatedly add
more and more echo to a sample for increasingly pronounced effects. As echo
effectively extends the length of a sample you may have to move the right
pointer further right to accommodate all the repeats.
Clicking on echo with the right button adds echo to any sound being fed in
from the STOS Maestro sampler cartridge in real time.
Reverb: Reverberation, to give it its full title, is produced by thousands of
extremely short echoes following hot on the heels of each other. They are so
short, in fact, that you cannot tell when one ends and another begins - they
blur together and seem to become an extension of the original sound. Reverb
produces a ringing, cavernous effect. Try it with voice samples and use it on
dripping sounds. If your game is set underground you will need reverb for
atmosphere.
Do a left click to add reverb to the sample between the pointers and right
click to add reverb in real time to a sound being played through the STOS
Maestro Plus sampler cartridge.
Hall: The type and quality of reverb will vary according to the environment.
Compare the reverb qualities of a concert hall with your bathroom, for
example. Hall reverb is more pronounced than Maestro's standard reverb - a
little slower, perhaps. Left click to apply it to the sample between the
pointers, right click to apply it to a sound coming in through the sampler
cartridge.
Room: This is the third type of reverb effect which STOS Maestro has to offer
and it's a little shorter than the others. As usual, left click to add echo
between the pointers, right click for the sampler cartridge.
Delay FX
--------
You can have a lot of fun and create lots of fascinating sounds with reverb
and echo.
Here are a few suggestions:
For a well-pronounced effect, give a sample 3,4, or more doses of echo or
reverb
Add both echo and reverb to a sample
Flip a sample, apply an effect and then flip it back.
Move the left pointer slightly before applying subsequent effects.
Use mix to create combinations of echo and reverb.
Split a sample (insert blank memory) and add an effect only to the middle of
it.
Don't forget to Magnify the sample in order to home in on selected areas.
Amplify: Amplifies the sample between the pointers to make it louder. This
can be very useful if you can't record your favourite sound at a high enough
volume. You can also apply it to a sample if it has undergone a lot of
editing. You will probably have noticed by now that lots of manipulation can
reduce the effective volume of the sample. But use Amplify sparingly as it
will increase the background noise as well. If you continuously amplify a
sample it will soon distort.
Pack: This is another unique feature to help you record even better samples.
It packs the data between the pointers, effectively halving the size of the
sample and saving lots of memory. It also means that your STOS Basic games
won't slow down as much when samples are playing.
In order to hear a packed sample at its original pitch you only need to
play it at half its sampled rate. For example, you could record a sound at
32KHz, Pack it twice and play it back at 8KHz. The quality will be better
than if you recorded at 8KHz because the pack routine takes an average
reading of the data (like Oversampling).
Fade In: Creates a Fade In on the sample between the pointers. The wider
apart the pointers, the slower the fade. You'll notice that this drastically
reduces the size of the sample in the display area.
Fade Out: Creates a Fade Out on the sample between the pointers. The comments
relating to Fade In apply here, too.
Soft: This is the opposite of amplify and reduces the volume of the sample
between the pointers, too much softening and you will probably notice an
increase in noise. While you may be able to amplify a softened sample back to
its original volume without too much signal deterioration, softening an
amplified sample will bring with some of the noise created by Amplify.
Filt: Passes the sample between the pointers through a low pass filter. This
passes the low frequencies and filters out the high ones. Noise tends to
reside in the high frequencies so use this to help reduce the noise level on
very noisy samples. It also "softens" a sound.
Specials: This rolls down another menu containing more display options.
About box: Gives you information about STOS Maestro - the version number and
the credits.
Filled Waveform: This option and the next two determine how samples are
displayed in the sample display area. This is the default option and shows
the waveform of the sample with the positive (upper) and negative (lower)
cycles filled in white and blue.
If you have a musical instrument which can produce sine waves (see the
introduction), plug it into the cartridge, sample a sine wave and magnify it.
This option will clearly show the sine wave shape in the display area.
Synthesisers often use a square wave to produce a clarinet sound. If you
can analyse either of these you will see the squarish waveforms (a clarinet
will produce waves which are not quite square due to additional harmonics).
Brass and string sounds are often constructed from sawtooth waves (sometimes
called ramp waves) and make for interesting analysis, too.
Envelope: This displays the volume envelope of the sample - in other words it
shows how loud it is, rather like the spectrum analysers. You will see that
the positive and negative cycles are identical (as if they had been reflected
along the central line) as you can't really have a negative volume.
Waveform Outline: This is similar to the Filled Waveform option but it shows
the waveform of the sample as an outline, just like you'd see it on an
oscilloscope. It's often easier to see the exact shape of a waveform when
displayed this way.
Oscilloscope: The STOS oscilloscope lets you see the shape of the sounds
which are entering the sampler cartridge. Most sounds in everyday life,
particularly music and the human voice, are very complex indeed and their
waveforms are very complex, too. Try it for yourself.
If you can produce sine waves you'll be able to see them quite clearly. Low
notes produce "longer" waves while higher notes bunch the waves closer
together. You will even be able to spot sine wave characteristics in the
spectrum analysers. Exit to the main screen by pressing the spacebar.
Exit: Click here to exit back to the Gem Desktop. If you have edited the
sample in memory, it will give you the option of saving before quitting.
Creating your own welcome sample
--------------------------------
As you enter STOS Maestro you are welcomed by a voice sample. You can
customise your own welcome sample using the following easy procedure:
1 Create a sample using Record at around 10KHz
2 Save the sample from the disc menu under the filename WELCOME.SAM, making
sure it's in the same folder from which you run MAESTRO.PRG
Every time you now load STOS Maestro it will pick up your sample and play it.
If this becomes annoying then just remove the WELCOME.SAM file from the
folder.
Now you know everything there is to know about STOS Maestro - Have fun!
--------------------------------------------------------------------------
| 2: Disco, Phaser and DEMOS |
--------------------------------------------------------------------------
STOS Maestro disco unit
The STOS Maestro Disco unit is a real- time digital delay programme. You can
load it directly from disc by double -clicking on DISCO.PRG or from the STOS
loading screen by selecting the 2 key on your Atari ST. You will of
course
need the STOS sampler cartridge to use this programme.
Make sure your ST is switched off before plugging the cartridge into the
ST's cartridge port. Plug a sound source into the cartridge. To hear exactly
what Disco does, it will help if you have control over the duration of the
sound - a microphone or musical keyboard is ideal. If you intend to use
music, then compose a piece which is fairly simple. Once you hear what's
going on you can try it out on the 1812 Overture! Disco is a digital echo
machine but unlike the echo function in STOS Maestro it only plays back a
single echo at a time. However the delay time is fully under your control and
can be in the range 0 -9.99 seconds. Disco plays the original sound as soon
as it enters the cartridge and then it plays it again after the delay period.
It's a continuous process so the delayed sound will be heard at the same time
as the original sound - trailing behind a little. This can produce some
fascinating overlapping effects.
Controlling Disco
-----------------
Disco is controlled with the function keys which are mainly used to alter the
delay:
-------------------------------------------------------------------------
| Function key | Effect |
|-------------------------------------------------------------------------|
| F1 | Increased by 10 milliseconds (100th of a second) |
| F2 | Decreased by 10 milliseconds |
| F3 | Increased by 100 milliseconds (10th of a second) |
| F4 | Decreased by 100 milliseconds |
| F5 | Increased by 1 second |
| F6 | Decreased by 1 second |
| F7 - F9 | Pauses the display when held down |
| F10 | Press twice to reset and default back to Desktop |
-------------------------------------------------------------------------
You can change the delay time as music is playing through the unit. Very
short delays will produce a chorus effect which "thickens" the sound or
longer delay times sound very effective if you can match the delay setting to
the beat of the music. Alternatively, offsetting the delay time-a little
faster or slower than the beat-can produce interesting effects, too, as the
music and the repeat move out of sync with each other. Try it with any music
of a rhythmic nature. It works extremely well with electronic music and many
of Jean Michel Jarre's tunes have suffered at the hands of (or been enhanced
by?) the Disco programme. The central area of the screen produces a graphic
display (spectrum analyzer) of the sound entering the cartridge port. Plug in
some music, turn the lights down, pump up the volume, watch and relax.
The STOS Phaser Program
The STOS Phaser is a small utility which we have included on the program
disc as an extra. Although it's a simple program it can produce some
fascinating effects. Load STOS Phaser directly by double-clicking on the
PHASER.TOS file or by loading it via STOSM.PRG.
Warning in order to use the phaser you require the STOS Maestro sampler
cartridge. Make sure your ST is switched off before plugging the hardware
into your ST's cartridge port.
Phasing is a very popular effect especially in electronic music, producing a
sort of sweeping effect. Play some music and listen for yourself. If you want
to know what a phaser actually does to a sound and how it produces it's
effects you need to know a little about waveforms. A detailed explanation is
beyond the scope of this manual and it's not strictly necessary-you can use
the programme without knowing the theory behind it. However, if you want a
visual analogy, think of a zebra walking behind a black garden fence-
sometimes you see different pits appearing and disappearing in a cyclic
fashion. A phaser does a similar kind of thing to the harmonics of a
sound. Harmonics are the particles of a sound which make it bright, hollow
brassy and so on. As it sweep through the harmonics, the tone of the sound
Changes. You will hear the effects of the phaser beat with sounds which
contain lots of harmonics such as brass and strings. Flutes, on the other hand,
don't contain many harmonies so there is less for the phaser to sweep
through.
Controlling The Phaser
The phaser is very easy to control - like the disco it only uses the function
keys.
f1 Increase the phaser key by one
f2 Decrease the phaser key by one
The phaser speed determines how quickly the can be very tranquil and
relaxing. At a faster speeds it can be quite hectic.
f3 Increase the phaser depth by one
f4 Decrease the phaser depth by one
Phaser depth is the degree or the amount of sweep. A low or shallow setting
can produce a very subtle effect. At greater depths it really rakes through
those harmonies.
f5 Select phaser sweep- SWP
f6 Select phaser forward sweep- FDW
f7 Select phaser backward sweep- BWD
These keys determine the direction of the sweep:f5 (up and down), f6 (down
only ) and f7 (up only).
f8 Turn phaser off
f9 Turn phaser on
f10 Reset computer and default to the Gem Desktop (must be pressed twice to
work)
Try out the Phaser by playing some of your favourite pieces of music through
it- using a fairly low depth and slow speed for a subtle effect, then
increase both gradually to taste.
The DEMO. TOS Files
If one of your Atari floppy disc drives is double sided then you will be able
to run these demos. Simply double click on a DEMO.TOS icon to play a tune.
The two STOS Maestro discs have a special dual format- single drive owners
can still use the discs but won't be able to access the demos. The programme
run from side one then load up data from side two of each disc. Turn up the
volume for an example of what can be achieved with STOS Maestro.
3:STOS MAESTRO BASIC INTERFACE
Installing The STOS Basic Extension File
Before you can access the sampler from Basic , you first need to install the
new commands onto your current STOS language disc. Load up STOS Basic, insert
the STOS Maestro programmes disc and enter the following command:
LOAD "\BASIC \INSTALL.BAS"
Once this has loaded, you should place a copy of your STOS language disc
into drive A and type:
run
The new Maestro extension can now be installed onto all your copies of STOS
Basic by pressing the E key. Select a STOS folder to update using the
resulting file selector. Once inside a STOS folder press return- the new
extension file will now be saved into the STOS folder. Since the installation
holds all the extension commands in a STOS memory bank, no disc swapping is
required.
If you own a copy of the STOS compiler, you should now place your back-up of
the compiler disc into drive A and press C. The appropriate compiler
extension can now be installed into the COMPILER folders in the same manner
as above. You can add sampled sounds to your Basic programmes and compile
them in the normal way.
The Maestro Accessory
A special memory bank system is used by the STOS Basic extension to hold
samples. THis makes loading in samples and playing them child's play. To make
life as easy as possible we've devised a powerful accessory capable of
generating sample banks from pre-recorded sample files.
This combines up to 32 separate samples in a single memory bank, which can
then be incorporated directly into your STOS Basic programs. You can enter it
from the Maestro disk with a line like :
accload "\basic\maestro"
Here is a breakdown of the various menu options.
STOS MENU
About Bank Creator : This displays a copyright message. Click on the left
mouse button to return to the main menu screen.
Quit : Exits back to your current program. Warning! Don't call this option
without saving your sample bank first!
Quit & Grab : Grabs the current samples installed into the ST's memory, and
places them into bank 5 of your current program. This option is only
available if Maestro has been loaded as an accessory.
DISK MENU : The disk menu allows you to load and save samples onto the disk.
Load SAMPLE.??? : Loads a sample into bank number 5. These samples are those
which have been directly imported from the STOS Maestro Plus cartridge (or
compatible). The Maestro accessory can be use with the output of most sound
samplers currently available for the Atari ST. This allows you to enter
samples from many commercial games. Look for files with extensions like .SAM,
.SMP or .SND. Feel free to experiment with this option as much as you like.
The worst thing that can happen in practice is that the sample will not load.
Load SAMPLE.MBK : This enters a memory bank previously created with the
Maestro accessory.
Load SAMPLE FOLDER : Loads an entire folder full of samples into memory. This
option is especially useful when using the disk, as it allows you to install
all of a folder's contents into a single memory bank in one smooth operation.
Save SAMPLE.MBK : Saves all the samples currently installed into memory. This
data can be subsequently loaded for use by the SAMPLAY and SAMMUSIC commands.
SAMPLE MENU
Delete Sample : Deletes one of the 32 possible samples from the ST's memory.
The sample to be erased is indicated using the number from 1 to 32.
Rename : Changes the name of one of the samples currently installed into the
memory.
Play Sample : Plays one of the samples which has been loaded into the
accessory. Before the sample is played, you will be requested for the speed.
This should be input as a number from 5 to 22.
MAESTRO TUTORIAL
We'll now show you how the various features of the Maestro accessory can be
actually used. Start off by loading the accessory from the Maestro disk with
:
dir$="\basic"
accnew:accload "maestro"
First enter the accessory from the Help menu by typing <HELP><F1>. Then place
the samples disk into drive A and select the LOAD SAMPLE.??? option from the
disk menu. This presents you with a standard STOS file selector. Now load a
sample by clicking on the SOUND folder, and choosing the file EXPLSION.SAM.
You can play this sample from the Sample menu using a speed setting of around
10.
This process can now be repeated for the samples LAZERGUN and PISTOL. Insert
a blank disk into drive A and save these samples with the SAVE.MBK option
from the disk menu. Use the filename EFFECTS.MBK for this purpose. Now exit
to the STOS Basic editor with Quit and type :
load "effects.mbk":rem Load samples into bank 5
These samples can be played from STOS Basic using the lines :
click off:sound init:rem initialise sound chip
samplay 1:rem Play Explosion
samplay 2:rem Laser
samplay 3:rem Gunshot
We'll now show you how you can load an entire folder full of samples in
exactly the same way. Call up Maestro using <HELP><F1>, and select the Load
Folder option from the Disk Menu. When the file selector appears, access the
VOICES folder in the normal way. Now move the mouse pointer over the filename
box and enter the text : SAM
The contents of the voices folder will now be automatically loaded into the
ST's memory. You can then save the data under the filename of VOICES.MBK by
placing a blank disk into drive A and calling the SAVE.MBK option.
Finally choose the Quit option to re-enter STOS Basic then type in the
following program.
load "voices.mbk"
10 click off:sound init:samspeed auto
20 for i=1 to 11
30 samplay i
40 wait key
50 next i
This pages through each of the 11 voices stores in memory bank number 5.
THE DRUM MACHINE
In order to illustrate the possible applications of this package, we have
included a simple Drum Machine on the Maestro disk. This can be loaded using
the line :
load "\basic\drums.bas"
When you run the program, you are presented with a picture of a drummer and
his dog. The action of the various instruments can be controlled through the
keyboard numbers from one to six. As you can see, some of these instruments
are fairly unusual!
Another feature is the R option which allows you to record long sequences of
drum beats into the ST's memory. This performance can be interrupted at any
time using the space-bar. Your composition can now be replayed by pressing P.
Notice how the program has cleverly preserved the exact timing of your key
presses.
The Drum Machine was written entirely in STOS Basic. You can therefore list
the program to the screen or the printer in the normal way. Interestingly
enough, the actual program is remarkably simple. The samples for the drums
are held in bank number 5, and the recording itself is stored in bank 6. Each
individual sound corresponds to a single entry in bank 6, with the gaps in
your music being represented by a Chr$(0)
Here are a few ideas for possible extensions :
1. Replace the drum samples in bank 5 with some of your own. Remember that
these samples should first be converted into the correct format using the
Maestro accessory.
2. Introduce the ability to change the pitch of a note during play. This
could be generated by assigning a row of keys to particular notes. You could
then simply replace the SAMPLAY instructions with the appropriate SAMMUSIC
commands.
3. Extend the number of available instruments. It's possible to add up to 32
different instruments to the drum machine.
4. Add the ability to load and save sequences on the disk. This would involve
saving bank 6 using the BSAVE command from STOS Basic.
5. Allow the user to speed up or slow down drum patterns he has recorded.
--------------------------------------------------------------------------
| 4 : STOS MAESTRO COMMANDS |
--------------------------------------------------------------------------
STOS Maestro instructions
The STOS Maestro extension includes a number of powerful instructions which
allow you to incorporate samples sounds directly into your own STOS Basic
programs. A demonstration of how these commands are used can be found in the
programs PLAYER.BAS and DRUMS.BAS on the STOS Maestro program disk.
The Playback Commands
These commands are used to play back a previously generated sound sample
within the STOS Basic system. Any programs which use these commands can run
independently of the STOS Maestro Plus cartridge.
SOUND INIT (Initialise the ST's sound chip)
The SOUND INIT command kills any existing sounds and prepares the sound chip
for use by the sampler instructions. It is normally called at the start of
a program like so.
10 click off:rem switch off keyboard clicks
20 sound init:rem initialise sound chip
The keyboard click will interfere with the sampler system. It is therefore
necessary to turn of the keyboard click when using the sampler.
SAMPLAY (play a sample from the current memory bank)
SAMPLAY plays one of the 32 possible samples stored in the current memory
bank (normally bank 5). N is the number of the sample, ranging from 1 to 32.
Example:
load "effects.mbk"
click off:sound init:samspeed auto
samplay 1:rem plays an explosion
samplay 2:rem laser beam
samplay 3:rem gun
This example uses the EFFECTS.MBK file created in the tutorial on the STOS
Maestro accessory. These samples are played back using the interrupts and are
completely independent of the rest of the STOS system. This means that you
can happily add sound effects to an arcade game such as Zoltar, without
slowing down any of the action.
Note that only a single sample can be played at any one time. So if you start
a new sample before the existing one has completed, the old sample will
immediately be replaced.
It's possible to exploit this feature to produce a number of intriguing
effects. Take the following example :
load "\voices.mbk"
10 click off:sound init:samspeed auto
20 for i=1 to 5
30 samplay i:wait 5
40 next i
This generates a noticeable stutter in the sampled voice. VOICES.MBK is an
example file created in the section on the Maestro accessory. It contains the
entire contents of the VOICE folder on the STOS disk. One minor limitation of
the SAMPLAY instruction is that it is unable to work alongside any of the
STOS music functions. If your program uses music, this should be suspended
with MUSIC FREEZE before a sample is played, then restarted after the sample
has been completed.
SAMSTOP (Stop the current sample)
The SAMSTOP command terminates all current sampling operations.
Example:
reserve as data 6,12000
bload"A:\sound\explsion.sam":rem load a sample from the samples folder
10 click off:sound init:samspeed auto
20 samraw start(6),start(6)+length(^):rem plays a sample
30 wait key:samstop
SAMSPEED (Set the sampling rate)
SAMSPEED n
SAmspeed enters the rate which will be used for any subsequent sampler
commands. N can range between 5 and 22KHz, with 10 KHz as the default.
Example:
load "voices.mbk":rem created with MAESTRO.ACB
10 click off:sound init
20 for i=5 to 22
30 samspeed i:samplay 1:wait 20
40 next i
Incidentally, while the STOS Maestro Plus cartridge is capable of working at
speeds of up to 32 KHZ, you are currently restricted to a maximum of 22 KHz
in your STOS Basic programs. In order to play 32 KHz samples from STOS Basic
you will need to use MAESTRO.PRG and call the Pack option from the FX Menu.
The compressed sample can then be played at a speed of 16Khz from STOS BAsic.
It's not 32KHz but it's the only alternative - STOS is too busy handling
sprites and all the other interrupts to play back samples at a rate faster
than 22 KHz.
SAMSPEED AUTO (Enter automatic sampling mode)
SAMSPEED AUTO automatically selects the appropriate sample speed for the
current sample. The automatic sampling mode expects the speed of the sample
to be encoded into the current memory bank during the recording process. This
information is included with all samples produced using the STOS Maestro
sampler programme. However if you try to use this option in conjunction with
samples created from another source, such as the SAMRECORD function, a syntax
error will be generated.
Also note that automatic is effectively canceled the next time you change
the sampling rate with SAMSPEED.
Example:
load"voices.mbk":rem Load some sound effects
10 click off:sound init
20 print"Default speed":samplay 1
30 print"Hit a key to continue":wait key
40 samspeed auto:rem Set appropriate speed automatically
50 print"Recorded speed":samplay 1
60 wait key
SAMSPEED MANUAL (Exit automatic sampling mode)
SAMSPEED MANUAL exits from automatic playback mode. It immediately returns
the sample speed back to the rate which was set by the most recent SAMSPEED
n command in the programme.
Example:
load"voices.mbk":rem Loads some sound effects
10 click off:sound init
20 samspeed 20:rem Set very fast speed
30 print"20 KHz":samplay 1
40 print"Hit a key to continue":wait key
50 samspeed auto:rem Set proper speed
60 print"Recorded speed":samplay 1
70 wait key:samspeed manual:rem Set samspeed back to 20KHz
80 print"20KHz again":samplay 1:wait key
SAMMUSIC (Play sample as a note)
SAMMUSIC n,'note'
The SAMMUSIC instruction allows you to alter the tone of a sample when it is
played. It's specifically intended for samples which represent some sort of
musical instrument. The effect is to widen the scale of the sound to
encompass the full range of musical notes.
N can be any one of the 32 possible samples stored in the current memory
bank.
'note' must be a string containing one of the following notes:
C,C#,D,D#,E,F,F#,G,G#,A,A#,B
The current pitch of the sample is assumed to be middle C.
Example:
load"voices.mbk":rem Load some effects created previously
10 click off:sound init
20 for i=1 to 12
30 read n$:print"Key";N$:sammusic 3,n$
40 wait key:rem Wait for the voice to be finished
50 next i
60 data "C","C#","D","D#","E","F","F#","G","G#","A","A#","B"
A better example of SAMMUSIC can be found in the file PLAYER.BAS on the
STOS maestro programme disc. This lets you load a sample into memory, and
then 'play' it from the keyboard. PLAYER assumes that the sampled found on
the disc is in raw form. It's therefore possible to load samples straight
off the samples disc. However, don't try to input .MBK files created with the
STOS Maestro accessory as you will generate an error message from the
programme.
SAMLOOP ON (Repeat a sampled sound)
After this command has been performed, any sample which is subsequently
played using the SAMPLAY, SAMMUSIC and SAMRAW functions will be continually
repeated from beginning to end.
reserve as data 6,12000
bload"A:\sound\explosion.sam",6:rem Load a sample from the samples disc
10 click off:sound init:samspeed auto
20 samloop on
30 samraw start(6),start(6)+length(6)
40 print"Press a key to end"
50 wait key:samstop:samloop off:click on
Like all the sampling commands, SAMLOOP is accomplished using an interrupt
routine. So once you have started the loop your programme can get on with
more important work, and forget about the sampler completely.
SAMLOOP OFF (Exit from a sample loop)
The SAMLOOP OFF command instructs the sample routine to play any future
samples exactly once. This instruction has no effect on the sample which is
currently being played. If you wish to halt an existing sample you will need
to use the SAMSTOP directive instead.
Example:
reserve as data 6,12000
load"A:\sound\explosion.sam",6:rem Load a sample from the samples disc
10 click off:sound init:samspeed 10
20 samloop on:rem Repeat the next sample
30 samraw start(6),start(6)+length(6):rem Play sample
40 print"Press a key to end"
50 wait key:samstop:samloop off:rem Turn off looping
60 samraw start(6),start(6)+length(6):rem Play a single shot
SAMDIR FORWARD (Play a sample from start to finish)
Normally all samples are played back in the direction they were originally
recorded. However you can change this using the SAMDIR BACKWARD command.
SAMDIR BACKWARD (Play a sample backwards)
This reverses the action of all future playback commands. Any subsequent
samples will now be played backwards until canceled by using SAMDIR FORWARD.
Example:
reserve as data 6,10000
bload"A:\voice\gameover.sam",6:rem Load a sample from the samples disc
10 click off:sound init
20 samdir backward
40 samraw start(6),start(6)+length(6)
50 wait key:samstop
The above programme plays the phrase "game over" back to front. You can
also call the SAMLOOP command with a reversed sample. Add the following
lines to the above example:
30 samloop on
55 samloop off
Although SAMDIR may seem rather pointless at first, it's actually
surprisingly useful. You can, for instance, create a convincing impression of
an "alien" language, by simply reversing normal speech, and then altering the
playback speed. This technique was used to great effect in the radio version
of The Hitch-hiker's Guide to the Galaxy.
SAMSWEEP ON (Repeatedly play a sample forwards and backwards)
The SAMSWEEP command is ideal for the generation of 'swishing' noises like
those produced by an aeroplane. The effect is to repeatedly cycle a sample
forwards and backwards. Note that, like SAMLOOP, the sweeping action only
takes effect from the next sample which is played.
Example:
reserve as data 6,784
bload"A:\sound\swosh.sam",6:rem Load a sample from the samples disc
10 click off:sound init
20 samsweep on:rem Start sweeping
30 samraw start(6),start(6)+784
50 wait key:samstop
SAMSWEEP OFF (Stop sweeping effect for the next sample)
This removes the sweeping effect from any sample which is subsequently played
with the SAMPLAY, SAMMUSIC, SAMRAW instructions. Like SAMLOOP OFF it has no
effect on the sample which is currently being performed.
SAMRAW (Plays samples straight from memory)
SAMRAW start,end
Plays a raw sample stored from addresses start to end. Raw samples can be
placed anywhere in memory. So it's perfectly possible to load a sample into a
string, and then subsequently manipulate it with normal string functions.
Example:
10 SOUND$=string$(chr$(0),12000)
20 bload"\VOICE\GAMEOVER.SAM",varptr(SOUND$)
30 samraw varptr(SOUND$),varptr(SOUND$)+len(SOUND$)
40 wait key
50 rem Chop the word "over" from "game over"
60 OVER$=right$(SOUND$,8000)
70 samraw varptr(OVER$),varptr(OVER$)+len(OVER$)
Raw samples can also be looped, reversed and swept using the appropriate
sampler commands.
Example:
10 reserve as work 8,100000:rem Reserve 100k to hold samples
15 click off:sound init:samloop off:samsweep off
20 F$=file select$("*.sam","Load sample to play")
30 if F$=""then end
40 open in#1,F$:L=lof(#1):close#1:rem Get length of sample
50 bload F$,8:rem Load sample
60 input"Playback speed";s
70 if S<5 or S>22 then print"Invalid Speed":goto 50
80 samspeed S
90 samraw,start(8),start(8)+L
100 print"Hit a key to continue":wait key:goto 20
SAMBANK (Select current bank for SAMPLAY and SAMMUSIC commands)
SAMBANK n
N is a number from 1 to 15 specifying a STOS memory bank to be used by the
sampler.
As a default, the SAMPLAY and SAMMUSIC operations expect a list of previously
created samples to be available from memory bank number 5. Unfortunately this
can cause serious problems for anyone wishing to add sampled sound to an
existing programme.
Supposing you wanted to include sound effects in a programme such as Zoltar.
In this case, you can't place the samples in bank 5, as this is already
allocated to one of the screens. You therefore need to change the current
sample bank with SAMBANK. See the section called Adding samples to your games
for more details of this procedure.
Another application is to allow you to incorporate more than the maximum of
32 samples in a STOS Basic programme.
Example:
load"effects.mbk",5
load"voices.mbk",6
10 click off:sound init:samspeed auto
20 sambank 6:rem Use bank number 6
30 for i=1 to 5
40 samplay i:print"Hit a key to continue":wait key:rem Press a key
50 next i
60 sambank 5:rem Set bank back to 5
70 goto 30:rem Playback 5 sound effects
SAMCOPY (Copy a sample from one place to another)
SAMCOPY start,end,dest
This is just a special version of the standard STOS copy command which allows
you to start copying from an odd location - that is, from any location
whether it is on a word boundary or not. SCREENCOPY only works on word
boundaries for reasons of speed.
Start is the beginning of the address which is to be moved. It can take any
value you wish, and it does not have to be even.
End is the address of the end of the sample which is to be copied.
Dest is the destination of the new sample.
Example :
10 reserve as work 10,30000:rem reserve 30K
20 input "place the sample disk in drive A";a$
30 samspeed 12
40 dir$="A:\VOICE\"
50 bload "gameover.sam",10:rem load a sample
55 rem make a second copy of the sample into bank 10
60 samcopy start(10),start(10)+10000,start(10)+10001
65 rem play the entire sample
70 samraw start(10),start(10)+length(10)
SAMPLACE (Return the current position in the sample)
p=SAMPLACE
The SAMPLACE function retrieves the present position in the sample which is
currently being played. This number is relative to the start of the sample.
The possible values taken by SAMPLACE range from 0 to the total sample size
(in bytes).
Imagine you had a sample which was 20K long. If you were to get the position
at the halfway point, a value of 10000 would be returned.
10 rem simple tape counter
20 click off:sound init:curs off:hide
30 input "Sample number";N
40 input "Sample rate";s
50 samspeed s:samplay n
60 XC=xcurs:YC=ycurs:P=samplace/1000:print"Tape counter:";P;" ";
65 locate XC,YC: if inkey$="" then 60
70 goto 30
The SAMPLACE function is often used to determine when a sample has finished
playing. This information is essential if you wish to combine melodies
produced from the MUSIC accessory with sampled sounds.
Example :
load "music.mbk";rem load from the STOS Basic accessory disk
load "effects.mbk":rem created previously with MAESTRO accessory
10 click off:music 1:tempo 30
20 if rnd(1000)<>3 then 20:rem produce random sound effects
30 music freeze:sound init:samplay 1
40 if samplace=11842 the samstop:music on:goto 20:rem sample 10K long
50 goto 40
THE SAMPLER CONTROL COMMANDS
These functions are designed solely for use with the STOS Maestro Plus
cartridge (or equivalent). They give you complete control over the various
features provided by the sampler and allow you to create customized sampling
programs in STOS BAsic. This opens the door to a bewildering range of
possible applications, form speech synthesizers to simple speech recognition
systems!
SAMRECORD (Records a sample from the sound cartridge)
SAMRECORD start,end
SAMRECORD starts the sampler running, and records a sample using the current
speed setting. the new sample is entered directly into the memory locations
between start and end. While the sample is being recorded, the sampled sound
is continuously played through your TV or monitor.
Start is the address of the start of the sample
End is the address of the end of the sample. When this point is reached, the
sampling process is automatically terminated.
Samples created using this function can be save to the disk and accessed
directly from either the Maestro program or the SAMRAW command.
Example :
10 rem recording a sample
20 click off:sound init
30 reserve as work 6,1024*50; rem reserve 50K for sample
40 input "SAmple Speed";s
50 if S<5 or S>22 then print "Invalid speed";goto 40
60 samspeed S
70 print "Prepare your recorder"
80 samthru:input "Hit return to start sampling";R$
85 print "REcording sample"
90 samrecord start(6),start(6)+1024*50
100 if samplace<49999 then 100:rem Wait until recording finished
110 print "Playing back sample"
120 samraw start(6),start(6)+length(6):rem play sample
130 if samplace<1024*50 then 130:rem wait until playback finished
140 input "Play again Y/N";A$:If A$="y" or A$="Y" then 120
150 goto 40
As you might expect, the sampling rate can be set up using the SAMSPEED n
instruction, and the sampling can be aborted at any time with SAMSTOP.
It's important to note that this instruction does store the recording speed
as part of the sample. So if you try to play back a sample using the SAMSPEED
AUTO instruction, an error will be generated.
SAMTHRU (Play the input from the sampler through the monitor's speaker)
The SAMTHRU command simply pipes the current sound output through your TV
speaker. This allows you to listen to the input without creating an actual
sample.
Example:
Place a tape in your recorder and press PLAY. Now type:
click off:sound init:samthru
This THRU mode can be interrupted at any time using the SAMSTOP command.
SAMPLE (Read the sample value directly from the cartridge port)
s=SAMPLE
S holds a value from -127 to +127 which represents the volume of the sound in
a digital form. The STOS Maestro Plus cartridge reads this value thousands of
times per second and uses it to create a digital representation of the
sampled sound.
Example:
10 click off:sound init:l=0:mode 1:cls:physic:cls back
20 ink 1:hide:samthru
30 S=sample/2:draw l,100 to 100-S:incl
40 if l>=640 then l=0:cls:physic:goto 30 else 30
Initialisation
--------------
This sets up the screen and reserves space for your samples in one of the
STOS Basic memory banks.
10 rem Sampler
20 mode 0:click off:sound init:rem Initialise sound chip
25 rem Set up screen
30 cls physic:cls back:windopen 21,5,38,19,0
50 rem reserve maximum available memory
60 MEM=free-50000:if mem>0 then reserve as work 6,MEM else print"Not
enough memory":end
Most of the above code is fairly obvious but pay special attention to line
60. This reserves all the currently available memory for the sample, leaving
50k for the programme itself.
Entering the user's commands
----------------------------
The input routine forms the heart of your sampling programme and interprets
the commands as they are entered by the user. You can make this routine as
simple or as complex as you wish. Commands can be entered using the keyboard,
STOS menus or the mouse. Here is a simple example of input routine.
65 rem Keyboard input routine
70 input"Input command";C$:C$=upper$(C$)
80 if C$="K"then gosub 490:goto 70:rem Set speed
90 if C$="P"then 170:rem Play sample
100 if C$="R"then 250:rem Record sample
110 if C$="T"then 320:rem Thru sample
120 if C$="L"then 450:rem Load sample
130 if C$="S"then 370:rem Save sample
140 if C$="Q"then samstop:default:end
150 print"Command not recognised":goto 70
We'll now go through each of these commands in turn and show you how they
can be implemented in STOS Basic.
Setting the sample speed
------------------------
490 rem Set speed
500 input"Sample speed";S
510 if S<5 or S>22 then samstop:boom:goto 500
520 samspeed S
530 return
The SET SPEED routine uses samspeed to set a sampling rate between 5 and
22KHz. Note the check in line 510.
Recording a sample
------------------
240 rem Record sample
250 if S=0 then gosub 490
260 gosub 550:rem position
270 samrecord start(6)+BEGIN,start(6)+FINISH
280 gosub 620:samstop:rem Display counter
290 input"Repeat sample ?";A$:if upper$(A$)="Y"then 270
300 input"Reset interval ?";A$:if upper$(A$)=Y"then 250
310 goto 70
This routine uses the SAMRECORD function to enter a sample into memory. The
gosub at line 250 is just to call to the set speed routine I showed you
earlier. This forces the user to choose a speed before recording the sample.
The size and position of the recording is set using a special Set Interval
routine like so:
540 rem Get starting point
550 input"Starting point";ST:BEGIN=ST*1000
560 if BEGIN<0 or BEGIN>MEM then print "Number must be between 0
and";MEM/1000:goto 550
570 input"Ending point";SP:FINISH=SP*1000
580 if FINISH<=BEGIN then print"End point must be greater than
start":goto 570
590 if FINISH>MEM then print"Number must be between 0 and"MEM/1000:goto
570
600 return
Each unit corresponds to a thousand bytes of the sample. So a start point
of 5 and an end point of 50 will record from locations START(6)+5000 to
START(6)+50000. Another useful routine is a Tape Counter which continuously
displays the current sampling position.
610 rem Print current position
620 curs off:hide
630 XC=xcurs:YC=ycurs:P=samplace/1000+ST:print"Tape counter:";P;" ";
635 if P<SP then locate XC,YC:goto 630
640 curs on:show
650 return
The equation P=samplace/1000+ST, converts the position in the current sample
to the position relative to the entire memory bank.
Playing a sample
----------------
160 rem Play sample
170 if S=0 then gosub 490
180 gosub 550:rem Get position
190 samraw start(6)+BEGIN,start(6)+FINISH
200 gosub 620:samstop:rem Display counter
210 print:input"Play again?";A$:if A$="Y"or A$="y"then 190
220 input"Reset interval?";A$:if A$="Y"or A$="y"then 170
230 goto 70
As with the record function, I've added a check for whether the sample
speed has been set previously. This compensates for the lack of the sample
speed in the recorded sound.
Playing a sample through the loudspeaker
----------------------------------------
This can be performed using the following code:
320 rem Thru
330 input"Press play";A$
340 samthru:print"Press the spacebar to stop"
350 if inkey$<>" "then 350
360 samstop:goto 70
Finally, we'll add the routines which allow you to save and load samples to
the disc.
370 rem Save sample to disc
380 F$=file select$("*.*","Save a sample")
390 if F$=""then 70
400 gosub 540
410 if dfree<FINISH-BEGIN then print"Not enough disc space":print"Try
again":goto 390
420 print"Saving ";F$
430 bsave F$,start(6)+BEGIN to start(6)+FINISH:goto 70
Note the call to Set Interval routine at 540, which enables you to save any
part of the sample independently.
Loading a sample
----------------
440 rem Load a sample
450 F$=file select$("*.*","Load a sample")
460 if F$=""then 70
470 print"Loading ";F$
480 bload F$,start(6):goto 70
Although the programme is undoubtedly crude, it's more than adequate for
adding the finishing touches to samples produced from MAESTRO.PRG You can
therefore fine tune your samples without having to leave the STOS Basic
environment. Feel free to modify it as much as you like for use with your own
programmes.
6:Tech ind
Adding sampled sounds to an existing programme
----------------------------------------------
If you've been using STOS Basic seriously for any appreciable length of time,
you'll probably have dozens of programmes which would sound great with a
little sampled sound. This is especially true for those wishing to enter the
STOS Gameswriter of the Year competition.
We'll now demonstrate how you can incorporate samples into a large STOS
Basic programme. In order to keep our examples as realistic as possible we'll
use the Zoltar game from the STOS Games disc.
Switch on your ST and load Zoltar into memory with a line like:
load"\zoltar\zoltar"
If you list this programme you will be confronted with several pages of
densely packed instructions.
The first step is to check which banks are currently being used by the
programme. You can do this by using the LISTBANK command:
listbank
Reserved memory banks:
1 sprites S:$0E9900 E:$0ED300 L:$003A00
3 music S:$0ED300 E:$0ED700 L:$000400
5 data S:$0ED700 E:$0EF200 L:$001B00
6 data S:$0EF200 E:$0EFF00 L:$000D00
The precise numbers aren't really important and will vary depending on your
system configuration. The only crucial fact is that bank number 5 is already
used - this clashes with the default memory bank used by the samplay
instruction. you will therefore need to change the sample bank somewhere
early in the programme using SAMBANK. In the case of Zoltar the first unused
bank is 7. You can set this at the start of Zoltar like so:
200 reserve as screen 10:cls 10:sambank 7
You can now incorporate the standard pieces of initialisation code which
will be required by your programme.
42 click off:sound init:samspeed auto:rem Initialise sound chip
The next phase is to make a list of the various sound effects which are
currently used in your game. If the programme is one of your own, this
process will be fairly trivial. But in the case of Zoltar you will need to
repeatedly scan the program with the SEARCH instruction. The table below
shows the lines which require changing.
Breakdown of the sound effects used in Zoltar
Line Sound commands Purpose
10465 envel 1,1000 : noise 3,2 Player fires a missile
10485 envel 4,750 : noise 3,15 Ship fires a missile
10500 envel 1,4000 : noise 3,31 Attacker destroyed
10515 envel 1,20000 : noise 3,31 Player destroyed
10810 envel 1,1000 : noise 3,2 Player fires a missile
10840 envel 4,750 : noise 3,15 Magedon fires a missile
10845 envel 1,20000 : noise 3,31 Player destroyed
10900 voice off : volume 16 : Magedon destroyed
envel 1,35000 : noise 31
The precise nature of these effects was discovered by simply calling them
directly from the editor. Once you have isolated the sound effects in your
programme you can then choose some appropriate samples from the samples disc.
These raw samples must now be combined into a single memory bank using the
Maestro accessory.
You are now in a position to incorporate these samples into your STOS Basic
programme.
load"effects.mbk",7:rem Load effects used by Zoltar
Now replace each of the NOISE instructions with the relevant SAMPLAY
command. When these have been introduced try running Zoltar - you will
quickly discover that the sampled sounds interfere with the music. As a
general rule it's safest to avoid the combination of music with sampled sound
altogether. Any accesses to the MUSIC instruction should therefore be
removed. This can be simplified by checking through the programme with the
SEARCH commands.
1014 music 1
2005 music off:M=1:T$="Please select option":gosub 11000
5000 WAVE=1:LIVES=3:SCRE=0:music 1:gosub 10400:music off
Alternatively, you can halt the music with MUSIC FREEZE before the sample is
played, and then restart it using the MUSIC ON command. So the SAMPLAY
instructions could be replaced by:
music freeze:samplay 1:wait 50:music on
Unfortunately this simple-minded approach will only work for games which
use interrupt driven sprites used by the majority of STOS Basic programmes.
Zoltar however, manipulates the sprites solely with the SPRITE command and
the game will be halted for about a second after every explosion. Also note
that above technique requires you to resume the music after a sample has been
completed. Otherwise the music will fail to resume after MUSIC ON statement.
Here are a few possible extensions to the Zoltar programme:
1 Add sampled voices for "GETREADY" or "BONUSPOINTS":See lines 1155 and 10405
2 Give each possible sound a different sample.
Finally I'll summarise the various steps in the modification procedure.
Adding sound to a STOS Basic game
---------------------------------
1 Check for the existence of bank 5. If it is already in use, set the sample
bank to the next free bank using SAMBANK.
2 Add the initialisation code to the start of the programme. This will
typically consist of the following instructions.
click off:sound init:samspeed auto
3 List the various sound effects used and create a bank of replacements
using the Maestro accessory.
4 Add the new effects to the appropriate points in your programme.
5 If your programme is using music you are presented with two possible
options.
Either remove the music completely, or halt the music using MUSIC FREEZE
before a sample is played and resume with MUSIC ON after it has finished.
Assembly language interface
---------------------------
If you have a little experience in assembly language, you will be delighted
to discover that any samples created using the STOS Maestro Plus cartridge
can be replayed using just a few lines of assembler.
In order to access these features, you will need to incorporate the echoed
found in the MAESTRO.OBJ file into your programme. This can be loaded at the
end of your programme using the INCBIN directive within your source file.
sampler incbin"maestro.obj"
If your assembler does not include this facility, you will be forced to
load the object file directly from the disc in your assembly language
programme. Full details of the required BIOS calls can be found in any decent
ST reference manual.
Since the sampler uses an interrupt routine, it cannot be guaranteed to
work with any existing interrupts which access the sound chip.
The calling procedure is simplicity itself. First define a number of
important system variables at the start of your programme like so:
Equates for accessing the routines and variables
SAMINIT EQU $000 ; Offset the initialisation routine
SAMPLAY EQU $020 ; Offset to the playback routine
SAMSTOP EQU $370 ; Offset to the samstop routine
AUTO EQU $3A2 ; Offset to a variable holding the AUTO status
TYPE EQU $3A8 ; Offset to a variable holding the samplermode
; TYPE(A6)=1 for forward play
; TYPE(A6)=2 for backwards play
; TYPE(A6)=3 for forwards loop
; TYPE(A6)=4 for backwards loop
; TYPE(A6)=5 for sweep
SPEED EQU$3AA
; Offset to variable controlling the speed. Permissible values
; range from 5 to 32 KiloHertz. Note this option only works if
; AUTO(A6) is set to ZERO
Now load the address of the sampler routine into a convenient address
register.
lea SAMPLER,a6
You must then initialise the sound chip using the SAMINIT function.
jsr SAMINIT(a6) ; Call routine to initialise sound chip
Finally enter supervisor mode with a call to SUPER and play your sample with:
lea SAMPLE_START_ADDR,a0 ; Start address of sample
move.l #SAMPLE_LENGTH,a1 ; Length of sample in bytes
lea SAMPLER,a6 ; Address of MAESTRO.OBJ code
move.w #1,TYPE(a6) ; Forward play
move.w #0,AUTO(a6) ; Set manual mode
move.w #10,SPEED(a6) ; Set sample speed to 10KHz
jsr SAMPLAY(a6) ; Call playback function
You can stop this sample at any time using the instructions:
lea SAMPLER,a6 ; Start address of .OBJ file
jsr SAMSTOP(a6)
Here are a couple of Macro definitions which simplify this procedure:
; PLAYSAM Play a sample
; Usage: playsam SAMPLER,START,END,SPEED
; SAMPLER=Start address of MAESTRO.OBJ file
; START=Start address of sample
; END=End address of sample
; SPEED=Speed of sample (in kilohertz)
SAMPLAY:MACRO LEA\1,a6 ; Get address of OBJ file in a6
jsr SAMINIT(a6) ; Init sound chip
move.l #\2,a0 ; Start of sample in a0.L
move.l #\3,a1 ; End of sample in a1.L
move.w #\4,SPEED(a6) ; Speed of play
clr.w AUTO(a6) ; Not auto speed select
move.w #1,TYPE(a6) ; Play forwards (TYPE=1)
jsr SAMPLAY(a6) ; Call routine
ENDM ; End macro
; SAMSTOP Stop a sample
; Usage:samstop SAMPLER
; SAMPLER=Start address of MAESTRO.OBJ file
SAMHALT:MACRO
lea \1,a6
jsr SAMSTOP(a6)2
ENDM
If you use these macros, don't forget to enter supervisor mode first! other
languages which incorporate some form of machine code call command will be
able to take advantage of the MAESTRO.OBJ file - simply set up the relevant
variables and call the code.
STOS Maestro Plus cartridge specifications:
-------------------------------------------
Signal to noise ratio 30.48 Dbs
Maximum frequency 98.5 KHz (not guaranteed)
Frequency Selection Software controlled
Resolution 8 Bits
Linearity +/- 0.5 LSB
Maximum input signal 2.5V RMS (peak to peak)
Anti-aliasing filter Yes
Internal successive approximation logic circuitry.
Chip conversion activated by ROM-SEL 3 on cartridge port.
******************************************************************
Well, here we are at the end of yet another mammoth (100K+) doc
brought to you by Sewer Software. Thanks again to Paul who typed
these docs for us, word for word from the original manual.
Back to STOS BASIC