M EQU 59

D4 = (10500000000/88/29366+M/2)/M
C4 = (10500000000/88/26163+M/2)/M
H3 = (10500000000/88/23347+M/2)/M
A3 = (10500000000/88/22000+M/2)/M
G3 = (10500000000/88/19600+M/2)/M
F3 = (10500000000/88/17461+M/2)/M
E3 = (10500000000/88/16392+M/2)/M
C3 = (10500000000/88/13081+M/2)/M

ORG 256
;---------------------------------------------------------------------
 MOV AL,0B6H		; not necesary
 OUT 43H,AL		; just make it more compatible
main:
 HLT
 INC BX 		; BX=timer counter
 MOV AL,BL		; get timer counter
 MOV AH,0		; put zero in AH
 XCHG BP,AX		; get channel1 data
 MOV AL,[BP+SI-256+table]
 MOV AH,M		; counter = data * Multiplier
 MUL AH
beep:
 OUT 42H,AL		; lowbyte of the counter
 MOV AL,AH
 OUT 42H,AL		; highbyte of the counter
 SALC			; if pause then speaker turn off
 OUT 61H,AL		; else turn on
;---------------------------------------------------------------------
 CBW			; if speaker off then AH=0
 IN AL,60H		; if ESC pressed then AL=1
 DEC AX 		; if AX=1 then EXIT
 JNZ main
RETN			; exit to DOS
;---------------------------------------------------------------------
table:			; notes data, 0 -> pause
DB 00,00,00,00,00,00,00,00,00,00,00,00

; part A

DB  C4,D4,C4,00,  00,00,00,00
DB  A3,A3,A3,00,  00,00,00,00

DB  C4,C4,00,00,  H3,H3,00,00
DB  A3,A3,00,00,  G3,G3,00,00

DB  A3,C4,A3,C4,  00,00,00,00
DB  F3,F3,F3,F3,  00,00,00,00

DB  G3,G3,G3,G3,  00,00,00,00
DB  C3,C3,C3,C3,  00,00,00,00

; part B

DB  F3,F3,00,00,  G3,G3,00,00
DB  A3,A3,00,00,  H3,H3,00,00

DB  C4,C4,C4,C4,  00,00,00,00
DB  C4,C4,00,00,  D4,D4,00,00

DB  C4,D4,C4,D4,  C4,D4,C4,D4
DB  C4,D4,C4,D4,  C4,D4,00,00

DB  C4,C4,C4,C4,  00,00,00,00
DB  00,00,00,00,  00,00,00,00

; part A

DB  C4,D4,C4,00,  00,00,00,00
DB  A3,A3,A3,00,  00,00,00,00

DB  C4,C4,00,00,  H3,H3,00,00
DB  A3,A3,00,00,  G3,G3,00,00

DB  A3,C4,A3,C4,  00,00,00,00
DB  F3,F3,F3,F3,  00,00,00,00

DB  G3,G3,G3,G3,  00,00,00,00
DB  C3,C3,C3,C3,  00,00,00,00

; part C

DB  F3,F3,00,00,  G3,G3,00,00
DB  A3,A3,00,00,  H3,H3,00,00

DB  A3,A3,A3,A3,  00,00,00,00
DB  G3,G3,G3,G3,  00,00,00,00

DB  F3,F3,F3,F3,  F3,F3,F3,F3
DB  F3,F3,00,00,  00,G3,F3,E3

DB  F3,F3,F3,F3,  00,00,00,00
DB  00,00,00,00,  00,00,00,00