myb@cernvax.cern.ch (michel bornand) (05/24/91)
Hi everybody. Here is a simple Pascal program for Apple IIGS with should
produce a sound at 16kHz. It does not work. What's wrong with it?
What did I miss?
Pascal testsound;
uses types,sound;
var gparms:SoundParamBlock;
oneangle:array[1..16]of byte;
begin
oneangle[1]:=$40;
oneangle[2]:=$50;
oneangle[3]:=$60;
oneangle[4]:=$70;
oneangle[5]:=$80;
oneangle[6]:=$90;
oneangle[7]:=$A0;
oneangle[8]:=$B0;
oneangle[9]:=$C0;
oneangle[10]:=$B0;
oneangle[11]:=$A0;
oneangle[12]:=$90;
oneangle[13]:=$80;
oneangle[14]:=$70;
oneangle[15]:=$60;
oneangle[16]:=$50;
gparms.waveStart:=@oneangle[1];
gparms.waveSize:=16;
gparms.fredOffset:=311;
gparms.DOCBuffer:=1;
gparms.bufferSize:=$0800;
gparms.nextWave:=@gparms;
gparms.volSetting:=255;
FFStartSound($0A01,@gparms);
end.
Thank you for all suggestions.
myb@cernvm.cern.chmyb@cernvax.cern.ch (michel bornand) (05/24/91)
Hi everybody! Here is a simple Pascal program for Apple IIGS which should
produce a sound at 16kHz. It does not work. What's wrong with it?
What did I miss?
program testsound;
uses types,sound;
var oneangle:array[1..16] of byte;
gsoundparms:SoundParamBlock;
begin
oneangle[1]:=$40;
oneangle[2]:=$50;
oneangle[3]:=$60;
oneangle[4]:=$70;
oneangle[5]:=$80;
oneangle[6]:=$90;
oneangle[7]:=$A0;
oneangle[8]:=$B0;
oneangle[9]:=$C0;
oneangle[10]:=$B0;
oneangle[11]:=$A0;
oneangle[12]:=$90;
oneangle[13]:=$80;
oneangle[14]:=$70;
oneangle[15]:=$60;
oneangle[16]:=$50;
gsoundparms.waveStart:=@oneangle;
gsoundparms.waveSize:=16;
gsoundparms.freqOffset:=311;
gsoundparms.DOCBuffer:=1;
gsoundparms.bufferSize:=$0800;
gsoundparms.nextwave:=@gsoundparms;
gsoundparms.volSetting:=255;
FFStartSound($0A01,@gsoundparms);
end.
Thank you for all suggestions.
Mickylanmaint@nssdca.gsfc.nasa.gov (Dave Yoest) (05/24/91)
In article <5397@cernvax.cern.ch>, myb@cernvax.cern.ch (michel bornand) writes... >Hi everybody! Here is a simple Pascal program for Apple IIGS which should >produce a sound at 16kHz. It does not work. What's wrong with it? >What did I miss? > >Thank you for all suggestions. > >Micky Your code may (or may not be) fine since I've never programed an Apple, but I suspect that you probably can't hear a 16KHZ tone anyway. The frequency response of the human ear rolls off above 10-14 KHZ, so you may need LOTS of volume to detect an audio signal at frequencies above 15KHZ and even then it may not be detectable. Do you have access to an oscilliscope, if so then connect a probe to the audio output and see if you are generating the signal electrically. It's also possible that IF you can hear a 16KHZ tone, that the speaker you're using won't reproduce a tone at that frequency. (DO dogs respond in any way when you test your program?) 8) Dave Yoest LAN M&O section supervisor NASA/Goddard Space Flight Center Greenbelt, Md. USA DYOEST@128.183.43.16 DYOEST@zaphod.gsfc.nasa.gov
lanmaint@nssdcb.gsfc.nasa.gov (Dave Yoest) (05/25/91)
In article <5397@cernvax.cern.ch>, myb@cernvax.cern.ch (michel bornand) writes... >Hi everybody! Here is a simple Pascal program for Apple IIGS which should >produce a sound at 16kHz. It does not work. What's wrong with it? >What did I miss? > code deleted >Thank you for all suggestions. > >Micky Well, I don't know any apple, so you code might be fine, it might not work at all. But keep the following in mind. 1. The frequency response of the human ear rolls off at roughly 14 KHZ. This means that at high frequencies you will need much more volume than the frequencies under 10KHZ. At some point you won't be able to hear the tone at all. This varies from individual to individual, and some rare individuals may be able to hear to 20 KHZ, but 16 KHZ is in the range where many people will not be able to detect the tone. 2. The speaker you are driving must be able to produce a 16KHZ tone. The speaker built into the monitor you are using might not be capable of producing a tone at this frequency. Suggestions: 1. Try generating a 12KHZ tone. You should be able to hear that. Then a 13KHZ, Then 14KHZ etc. You may be able to determine if you can hear a 16KHZ tone. If you've never heard a 16KHZ tone before, you might not have a concept of what a tone of that frequency sounds like. I used to work on a lot of TV equipment , and with practice could detect the Horizontal oscillator frequency (actually the resonation of mechanical parts in the horizontal) at 15,734 HZ. It took some time to gain this ability because I didn't have the concept of a 15KHZ tone at first. The step-up method might help you gain this concept. 2. Preferred.... Use an oscilliscope connected to the audio output and look for the electrical signal that you want to drive the speaker with. This method will also allow you to verify the accuracy of the frequency. 3. See if the dogs in your area respond. 8-) Dave Yoest LAN M&O Section Supervisor NASA/Goddard Space Flight Center Greenbelt, Md. 20771 DYOEST@128.183.43.16 DYOEST@zaphod.gsfc.nasa.gov
jmuller@Stardent.COM (Jim Muller) (05/25/91)
In <5395@cernvax.cern.ch> myb@cernvax.cern.ch (michel bornand) writes: >Here is a simple Pascal program... What's wrong with it? [program deleted] Pardon me but this triggered one of my pet peeves. As far as can be told by anyone who looks at your program and only your program, there isn't anything wrong with it. Is there anything wrong with how you used some of the other stuff from the programming environment? I dunno'! You asked the wrong question, because if there is a problem, it isn't in the Pascal at all. It is somewhere else. ---------------------- What's wrong with this? program foo; #include 'zip1.h' #include 'zip2.h' #include 'zip3.h' main { }; (...yawn...oh, I forgot, AT&T changed /usr/include/sys/zip1.h last month, so we need to put in a #define...or maybe we should leave it alone so it will be portable and just compile wtih -D<whatever>...) ---------------------- What the world needs is a good set of rules, and enough exceptions that nobody has to obey them. Even better, let's have more Standards! The more Standards, the better! -- __~o\____ ------------|\-----| Jim Muller ~ '-0-----0-` --------|~--o|\|---:| { repeat as } jmuller@stardent.com -~-~----~-----~~------------o|-----o|----| { necessary }
parkern@jacobs.CS.ORST.EDU (Neil Parker) (05/25/91)
In article <5395@cernvax.cern.ch> myb@cernvax.cern.ch (michel bornand) writes: >Hi everybody. Here is a simple Pascal program for Apple IIGS with should >produce a sound at 16kHz. It does not work. What's wrong with it? >What did I miss? Well...now that I'm at home where my manuals are, I guess I'll take a stab at this... >Pascal testsound; ^^^^^^ Huh? Do you mean "Program testsound;"? > >uses types,sound; > >var gparms:SoundParamBlock; > oneangle:array[1..16]of byte; ^^^ I don't know what version of Pascal you're using, but if it's TML Pascal, you'll need "packed" in front of "array"-- otherwise your 8-bit bytes will all be 16 bits wide... > >begin >[lotsa oneangle assignments deleted] > gparms.waveStart:=@oneangle[1]; > gparms.waveSize:=16; ^^ This says your waveform is 16 *PAGES* long, not 16 bytes! The smallest possible waveform is 1 page. > gparms.fredOffset:=311; > gparms.DOCBuffer:=1; ^ Toolbox Ref 3 says the HIGH byte is significant, not the low byte--this should be $100, not 1. > gparms.bufferSize:=$0800; ^^^^ Only the lowest 3 bits of this field are significant. The DOC buffer will be 2^bufferSize pages long. (Note that the resolution bits will also be initialized from this value, so changing it will change the pitch of your tone.) > gparms.nextWave:=@gparms; > gparms.volSetting:=255; > FFStartSound($0A01,@gparms); > >end. ^^^ Does your Pascal compiler generate an implicit QUIT call when execution "runs off the end" like this? I seem to recall reading somewhere that QUIT shuts down the tools, including the Sound Manager... Speaking of shutting down tools, did you remember to call SoundStartUp? I didn't see see it anywhere in your code sample... Suggestions: * Find out how your compiler handles array packing. * Make sure the length of your waveform is a multiple of 256. * Read pages 47-3 through 47-5 of Toolbox Ref 3. - Neil Parker -- Neil Parker No cute ASCII art...no cute quote...no cute parkern@jacobs.cs.orst.edu disclaimer...no deposit, no return... parker@corona.uoregon.edu (This space intentionally left blank: )