0 ' evolutionary etude no.1  jim cuomo - for ORIC 
	1 GOSUB 80
	9 FOR zz=1 TO dr : GOSUB 20 : NEXT zz : END

20 FOR i=1 TO pp
	25 IF nt+pr<0 THEN nt=25 : GOSUB 95	
	27 IF tt<1 THEN tt=1 : GOSUB 60
	32 nt=nt+pr : GOSUB 40 : NEXT i
	39 RETURN 
40 pr=INT(RND(1)*rd)
	41 IF pr=6 THEN pr=-1 : IF pr=7 THEN pr=-2 
	42 IF pr=8 THEN pr=-3 : IF pr=9 THEN pr=-4 : IF pr=10 THEN pr=-5
	46 tt=pr : IF pr>5 THEN tt=1 : IF nt>tl THEN nt=1
	49 RETURN
60 gg= nt+pr : kk=gg/12
	61 hh=INT(kk) : ii=((kk-hh)*12)
	65 IF ii>12 THEN ii=12: IF ii<1 THEN ii=1
	67 PLAY 7,0,1,11111 : MUSIC ch,hh,ii,0
	69 RETURN
80 ' PARAMETERS
	81 nt=33 : tt=1 : pr=1  : dr=66  : tl=88 : pp=20 : rd=10
	82 ' nt=base tone / dr=total iterations/ pr=interval jump / pp=event cycles
	83 ' rd=choices / tt=note length / tl=top limit  
	84 ' subroutine 20 = check limits and launch play / subroutine 40 = refresh
	85 ' subroutine 60 = convert to oric octaves and play / subroutine 80 =initialize parameters 
	86 ' subroutine 95 = align interval jumps and open channels
	89 RETURN
95 IF PR=3 THEN CH=3: IF PR=2 THEN CH=2 : IF PR=1 THEN CH=1
	99 RETURN
100 ' copyright 2007 pigeon music "evolutionary etude"