4 ms·

The data-over-sound library that I implemented (ggwave) and use in this example implements a modified DTMF protocol. Instead of only 2 tones, I use variable num

The data-over-sound library that I implemented (ggwave) and use in this example implements a modified DTMF protocol. Instead of only 2 tones, I use variable number of tones (usually 6) + error correction. In r2t2, I use a single-tone encoding, since the buzzer can emit just a single frequency.

gugagore 5y ago
> In r2t2, I use a single-tone encoding, since the buzzer can emit just a single frequency. That's not wrong, but also not the whole truth. https://en.m.wikipedia.org/wiki/PC_speaker#Pulse-width_modulation https://en.m.wikipedia.org/wiki/PC_speaker#Pulse-width_modul...
- deathanatos 5y ago
  From the Wikipedia article's citations: http://www.oldskool.org/sound/pc/#digitized http://www.oldskool.org/sound/pc/#digitized I lived through the PC speaker, and never heard anything like this ever emitted from one. It's crazy how good those waveforms sound, if they're representative of the hardware… I remember how amazing it was when we got our first soundcard installed and working, too. Games were much more interesting with real sound-effects.
  - a-dub 5y ago
    there was some name for it when it first started showing up in games, "puresound" or something.... yes, it would make jaws drop when the speaker stopped squeeping and started rendering digital audio. i think eventually windows added an sound driver that did pwm on the speaker. it was one of those really cool hacks that blew your mind when you first saw them. (like people playing music with disk drive stepper motors, i guess exactly like that heh) edit: found it: https://en.wikipedia.org/wiki/RealSound https://en.wikipedia.org/wiki/RealSound
    - BBC-vs-neolibs 5y ago
      There was a driver for Windows 3.x (third party, I think) which made it so Windows programs could play samples. But the computer was unresponsive during playback. It was still semi-useful, you got the little Windows sounds playing, and if I recall correctly, there was a Windows Zeppelin game which was more fun with sporadic sound samples playing. I upgraded my mothers 80286 PC clone with a separate ISA 8-bit MFM harddisk interface. I put in an 80486 (SX?) motherboard, which of course had IDE disk connectors. But, partly because I didn't have any spare IDE disk, and partly to make it a plug-in upgrade, I just moved over the ISA card to the 80486 motherboard and called it a day. It was actually a very productive setup, Word 6 was really fast on that machine and the little sounds from the PC speaker driver as a nice novelty.

gugagore 5y ago

> In r2t2, I use a single-tone encoding, since the buzzer can emit just a single frequency. That's not wrong, but also not the whole truth. https://en.m.wikipedia.org/wiki/PC_speaker#Pulse-width_modulation https://en.m.wikipedia.org/wiki/PC_speaker#Pulse-width_modul...

deathanatos 5y ago
From the Wikipedia article's citations: http://www.oldskool.org/sound/pc/#digitized http://www.oldskool.org/sound/pc/#digitized I lived through the PC speaker, and never heard anything like this ever emitted from one. It's crazy how good those waveforms sound, if they're representative of the hardware… I remember how amazing it was when we got our first soundcard installed and working, too. Games were much more interesting with real sound-effects.
- a-dub 5y ago
  there was some name for it when it first started showing up in games, "puresound" or something.... yes, it would make jaws drop when the speaker stopped squeeping and started rendering digital audio. i think eventually windows added an sound driver that did pwm on the speaker. it was one of those really cool hacks that blew your mind when you first saw them. (like people playing music with disk drive stepper motors, i guess exactly like that heh) edit: found it: https://en.wikipedia.org/wiki/RealSound https://en.wikipedia.org/wiki/RealSound
  - BBC-vs-neolibs 5y ago
    There was a driver for Windows 3.x (third party, I think) which made it so Windows programs could play samples. But the computer was unresponsive during playback. It was still semi-useful, you got the little Windows sounds playing, and if I recall correctly, there was a Windows Zeppelin game which was more fun with sporadic sound samples playing. I upgraded my mothers 80286 PC clone with a separate ISA 8-bit MFM harddisk interface. I put in an 80486 (SX?) motherboard, which of course had IDE disk connectors. But, partly because I didn't have any spare IDE disk, and partly to make it a plug-in upgrade, I just moved over the ISA card to the 80486 motherboard and called it a day. It was actually a very productive setup, Word 6 was really fast on that machine and the little sounds from the PC speaker driver as a nice novelty.