Breaking News and Opinion on The Huffington Post. Busy, Busy, Busy. Larry Osterman's WebLog. Earlier today, someone asked me why 64bit versions of windows don’t support the internal PC speaker beeps. The answer is somewhat complicated and ends up being an interesting intersection between a host of conflicting tensions in the PC ecosystem. Let’s start by talking about how the Beep hardware worked way back in the day[1]. The original IBM PC contained an Intel 8254 programmable interval timer chip to manage the system clock. Because the IBM engineers felt that the PC needed to be able to play sound (but not particularly high quality sound), they decided that they could use the 8254 as a very primitive square wave generator.
To do this, they programmed the 3rd timer on the chip to operate in Square Wave mode and to count down with the desired output frequency. This caused the Out2 line on the chip to toggle from high to low every time the clock went to 0. The Beep() Win32 API is basically a thin wrapper around the 8254 PIC functionality. It turns out that they couldn’t. The ADA? Schneier on Security. Getwired.com. Amy's Health Blog | Come and learn about my journey with breast cancer. Brian's Mind.