shangc@azure.UUCP (02/24/84)
Sorry about posting this again. I did not make my self clear last time.
I have a Tecmar graphics board. The software I am writing uses the high-res
graphics mode. I like to make the PC beeps without using either putchar('^G')
or printf("^G") because I don't want to include all the printf related runtime
routines if I don't have to. Beside, they may not work in the graphics mode
either ( I have not tried them yet). I would appreciate if anyone has experience
in writing something to the sound port to make the PC beeps in C or assembly
code. Thanks.
Shang Chyoujim@randvax.ARPA (Jim Gillogly) (02/28/84)
---------- There's a beep routine in the ROM at location E666. It produces a beep at 896 Hz (by my computations) (as opposed to the 1000 Hz that the comments claim). It reads as follows: BEEP PROC NEAR MOV AL,10110110B ;SEL TIM 2,LSB,MSB,BINARY OUT TIMER+3,AL ;WRITE THE TIMER MODE REG MOV AX,533H ;DIVISOR FOR 896 HZ OUT TIMER+2,AL ;WRITE TIMER 2 CNT - LSB MOV AL,AH OUT TIMER+2,AL ;WRITE TIMER 2 CNT - MSB IN AL,PORT_B ;GET CURRENT SETTING OF PORT MOV AH,AL ;SAVE THAT SETTING1