World: r3wp

seems not

so, i have to do something like that, to set the T flag, i mean :
 
AND tmp 255
eq.i  tmp 255

i have to do many operations like that to emulate the Z80 8-bit ship, 
Z80 modify his T-flag after any logical operation. i think Rebcode 
should do that  too :-)

Please write it to Rambo, better now, before R3

done

another prob is that all opcode operate on 32 bit integers only, 
in my case it would be cool if they can act as well on chars (8 bit)

i can do without, but my code is more verbose

...and slower

espacially with bit rotation opcode, which are useless in my case 
^^^

i need a speed reverse byte function with rebcode , for example 1100 
0000 => 000 0011
any idea ?

* 1100 0000 =>  0000 0011

I get strange result from the sin opcode, is there something special 
to know or is it a bug ?

rad or degres?

degree

I try with rad too but I should make a mistake

I'm not an expert only that I know by having many 3d cgi scripts 
that many apis have a mix and match of rad and degres... but it seems 
you looked at that too...

To test, I use this code :

test-sin: rebcode [value [decimal!]][sin value return value]

>> test-sin 90.
== 0.893996663600558
>> test-sin 100.
== -0.506365641109759
>> test-sin 0.0
== 0.0
>> test-sin 1.
== 0.841470984807897
>> test-sin .1
== 9.98334166468282E-2
>>

hum... its possible that some values just don't map directly to precise 
values (floating point errors)

but I agree that sin 90 should give you something closer to 1

et sin 1 devrait donner quelque chose de proche de 0

sorry in english, and sin 1 should give something near to 0

just tested  and well... the values supplied really are in radians 
 :-)

>> sine/radians 90
== 0.893996663600556

and a radian is pi / 2, right ?

2 * pi

Yes, right. It's OK now my script is running well. Thanks you.

Thanks to rebcode I can generate 6 minutes of music in 20 seconds 
instead of 5 minutes with a standard script. Great.

if you want fast sine, use tables, it's 10x times faster (that's 
without interpolation, but even with interpolation it will be still 
faster).

or if you need continuos sine wave, use self oscilating filter

I'm a newbe in music generation so ... I don't know what is self 
oscilating filter.

you can generate sine wave aproximation faster than using sin func

some example code (in C, but easy to rewrite):

float a = 2.f*(float)sin(Pi*frequency/samplerate);

float s[2];

s[0] = 0.5f;
s[1] = 0.f;

loop:
s[0] = s[0] - a*s[1];
s[1] = s[1] + a*s[0];
output_sine = s[0];
output_cosine = s[1]

this is much faster than calling SIN

Very simple indeed. I will test.

have you seen my Sintezar PM-101 in rebol.org library? maybe it will 
be interesting for you. I've got rebcode version on my disk, but 
because rebcode is not part of official rebol, it's not released. 
if you're interested, i can send you some examples. now i'm rewriting 
that synth as VST instrument in C(++), it's much faster then :)

No, I will look at now.

Thanks Rebolek, I reduce the time to produce 6 minutes 44 of music 
from 20 to 15 second.

you're welcome. 25x faster, very nice!

btw, what are you generating? it's your own synth, or some emulation? 
It's very interesting for me :)

It's to emulate the PSG AY-3-8910
Just for the fun and to understand a little about music

oh I see. But I thought AY-3-8910 has 4bit osc. with square and saw 
waves(plus some combinations), no sine? or does it have same lfo 
with better resolution and sine wave? don't remember the architecture 
corectly.

Yes that's right, 3 channel plus one for the noise, and square wave.

But it's enough complex to start and understand music generation 
for me.

With a simple parameter, I can switch between square wave or sine 
wave, it's quiet interresting to listen the difference.

I put the script here : http://www.rebol.org/cgi-bin/cgiwrap/rebol/view-script.r?script=psg-ay-3-8910-study.r

that's great Coccinelle! nice to see more and more people using REBOL 
for audio stuff. Maybe R3 will have the annoying audio-click bug 
fixed ;)

btw, I'm just reading your code, there's [rate: 44200], you probably 
meant [rate: 44100], taht's default CD sampling frequency

If I ever have free time again (not complaining, it's good to have 
work :-), I was thinking it would be fun to do a dialect for binaural 
beats, ala SBAGen.

I didn't know for 44'100. I have seen in some script 44'200, that's 
why I use this value.

The script detect automaticaly if the VM present or not, that's why 
the algorithm is twice.

I will imagine something to draw the wave also using rebcode, it 
should be very similar.

44'100 is correct, as the CD standard anyway.

Coccinelle: that's good idea with auto-detection. I was thinking 
about something simmilar for Sintezar once, auto-switching between 
rebol version, rebcode version and for /PRO C-library version. But 
I never wrote it, as nobody's using it anyway :) 

(I've got all three codes, rebol, rebcode and C-library, but not 
the autoswitch).