mmm... Ok, so on MSX what you get is that you have to accurately set the volume only on one edge instead of two... but that does not sound very useful as you still need to accurately count the whole time... I mean as you still need to calculate the whole time there is no much difference to playing these kind of sounds without PSG (ie. with key click) by changing the pulse on both edges accurately. -> Technically nice trick, but seems useless (on our platform)

3rd time... So the "save" is that instead of "accurate change, accurate change, accurate change" you can do "accurate change, almost accurate change, accurate change" instead. Right?

I posted some example code on the previous page just before your reply .

As for usefulness, with fully manual CPU timing on an ISR the tone frequency will be hard to get stable; with the PSG at least the base frequency will be solid, the pulse width (duty cycle) may jitter or drift a little but this is probably acceptable.

It's a feature in TriloTracker too:

http://trilobyte-msx.com/TriloTracker/index.php/Effects#B1y_...

That’s for SCC, surely...

yep.

Still have it on my todo list to make some song with TT(scc) to use all those nifty tricks not available in the FM version

Oh yeah, derp.

I wanted to tell a secret. the SCC is a SID. it has

pulse width

triangle

sawtooth

square

article: how to enable the filter on SCC the digital synthesizer pick a waveform. add a sine. divide by 2. done.

Interesting point of view. It does sound different I think, although I don't think anyone has used the scc this way?

Also that filter trick works well and not difficult to implement? Maybe suggest it to Huey for trilotracker

I remember ideas of a waveform morphing feature, I dont know whether it is finished. that maybe could move to the middle of a waveform and a sine.

another way is say load channel 4 channel 5 with sinus.

and the thing you want to filter, set halve volume, copy the whole column over to channel 4, channel 4 plays all the same, except with sinus.

but, I told the filter story just to give an idea of possibilities.

the first nice thing is to try out pulse width. and then vibrato wiggle its percentage.

and then you practically got the whole SID topic.

this BASIC makes the SCC sound like in church. maybe the chip could do arcade r-type, who knows.

using a BASIC program to add sinuses. or calculate other ideas.

in openmsx with toggle_scc_viever you can see the curves

SCC needed in slot 1. In machine code after the "3E", that gotta be slot ID.

it takes a while to make the sinuses, then press enter for sound.

autoexec.bas

10 poke &hf677,&hc2 : poke &hf676,&h01 : poke &hc200,0 20 run"loader.bas"

loader.bas

10 screen 0 : width 40 : key off : ?:?:?:?"SCC TEST CENTER :)" 20 b3 = &h9000 'bank3 31 w1 = &h9800 32 w2 = &h9820 33 w3 = &h9840 34 w4 = &h9860 41 f1 = &h9880 42 f2 = &h9882 43 f3 = &h9884 44 f4 = &h9886 45 f5 = &h9888 51 v1 = &h988a 52 v2 = &h988b 53 v3 = &h988c 54 v4 = &h988d 55 v5 = &h988e 60 o = &h988f 'on/off bits 70 d = &h98E0 'deformation register 100 restore 9200 : read a : defusr = a : gosub 9000 : x=usr(0) 'scc subslot 101 'restore 9300 : read a : defusr1 = a : gosub 9000 'write wave, addr in defusr 120 poke b3,&h3f 140 poke o,&b11111 'all channels on 150 poke v4,0 1000 for i = 0 to 31 1010 n = 60 1020 a = cos(i/32*2*3.1415926 *1)/1 * n 1021 a = a + cos(i/32*2*3.1415926 *2)/2 * n 1022'a = a + cos(i/32*2*3.1415926 *3)/3 * n 1023 a = a + cos(i/32*2*3.1415926 *4)/4 * n 1024'a = a + cos(i/32*2*3.1415926 *5)/5 * n 1025'a = a + cos(i/32*2*3.1415926 *6)/6 * n 1026'a = a + cos(i/32*2*3.1415926 *7)/7 * n 1027 a = a + cos(i/32*2*3.1415926 *8)/8 * n 1028'a = a + cos(i/32*2*3.1415926 *9)/9 * n 1029 a = a + cos(i/32*2*3.1415926*16)/16 * n 1030'a = a + cos(i/32*2*3.1415926 *1*3)/1 * n 1031'a = a + cos(i/32*2*3.1415926 *2*3)/2 * n 1032'a = a + cos(i/32*2*3.1415926 *3*3)/3 * n 1033'a = a + cos(i/32*2*3.1415926 *4*3)/4 * n 1034'a = a + cos(i/32*2*3.1415926 *5*3)/5 * n 1035'a = a + cos(i/32*2*3.1415926 *6*3)/6 * n 1036'a = a + cos(i/32*2*3.1415926 *7*3)/7 * n 1037'a = a + cos(i/32*2*3.1415926 *8*3)/8 * n 1038'a = a + cos(i/32*2*3.1415926 *9*3)/9 * n 1039'a = a + cos(i/32*2*3.1415926*16*3)/16 * n 1040 if a > 127 then a = 127 1050 if a < -128 then a = -128 1060 poke w4+i,a and 255 1100 next 2000 poke f4,0 : poke f4+1,2 2100 input a 2110 for i = 0 to 15 step 1 : poke v4,i : next 2112 for i = 15 to 14 step -0.05 : poke v4,i : next 2114 for i = 14 to 8 step 1 : poke v4,i : next 2120 for i = 7 to 0 step -0.08 : poke v4,i : next 2210 ''for i = 0 to 15 step 1 : poke v4,i : next 2212 'for i = 15 to 14 step -0.2 : poke v4,i : next 2214 'for i = 14 to 6 step 1 : poke v4,i : next 2220 'for i = 6 to 0 step -0.05 : poke v4,i : next 2300 goto 2100 8900 poke v1,0 : poke v2,0 : poke v3,0 : poke v4,0 : poke v5,0 : poke d,0 8910 ?":)":end 9000 a$ = "" 9020 if a$="" then read a$ 9032 if left$(a$,1)="$" then b$=left$(a$,1) : a$=mid$(a$,2) : return 9034 if left$(a$,1)="_" then b$=left$(a$,1) : a$=mid$(a$,2) : goto 9020 9040 if left$(a$,2)="1>" then b$=left$(a$,2) : a$=mid$(a$,3) : l1 = a : goto 9020 9042 if left$(a$,2)="2>" then b$=left$(a$,2) : a$=mid$(a$,3) : l2 = a : goto 9020 9050 if left$(a$,2)="<1" then b$=left$(a$,2) : a$=mid$(a$,3) : b$ = hex$((l1-a-1)AND255) : goto 9110 9052 if left$(a$,2)="<2" then b$=left$(a$,2) : a$=mid$(a$,3) : b$ = hex$((l2-a-1)AND255) : goto 9110 9100 b$=left$(a$,2) : a$=mid$(a$,3) 9110 poke a,val("&h"+b$) : a = a + 1 9120 goto 9020 9200 data &hc000 9210 data 3E01_210080_CD2400_C9$ 9300 data &hc100 9310 data 2A9AF3_3E00_0620_1>7723C60810<1c9$