3 ms·

Interesting how much analog architecture was used. Today everything is processed digitally with ADC/DAC at the edge. Those old 8-bit MHz-class processors and

Interesting how much analog architecture was used. Today everything is processed digitally with ADC/DAC at the edge. Those old 8-bit MHz-class processors and memory chips lacked the horsepower to synthesize sounds without disrupting gameplay.

chillingeffect 6y ago
Even for a sound chip, analog was unusual. a lot of the arcade games from that era and for another 10-15 years would often dedicate whole CPUs, such as Z80s and 6809s to sound. e.g. run some classics in MAME and it displays the sound chip(s) used in each game. Some of them have as many or more cycles used than the game CPU :) the tradeoff this chip made was fewer transistors and cost in exchange for not being very music, or able to be tuned well. it really was more a sound effect chip then a music chip.
- zerocrates 6y ago
  This has me thinking of the era when the LaserWriter printer had a significantly faster CPU and more RAM than the Macs it was paired with. The complexities of interfacing with the analog world...
  - jecel 6y ago
    The LaserWriter had to run the Postscript interpreter, which required a lot more CPU power than just generating Postscript files like the Mac did.
tenebrisalietum 6y ago
The Apple II has a single register that toggles the voltage to a speaker, allowing 100% CPU-driven construction of any square wave you want. I think other systems did something similar on cassette ports. That's an example of the power available to an 8-bit class CPU without any extra hardware - you can do a lot with PWM and high-frequency attenuation and such but definitely limited.
- joezydeco 6y ago
  1-bit sound construction was discussed earlier this week on HN: https://news.ycombinator.com/item?id=23144469 https://news.ycombinator.com/item?id=23144469
- ddingus 6y ago
  A lot of game sounds were found by placing writes to the speaker in various game event loops. The result was lean sounds, but they also made a lot of sense.
- londons_explore 6y ago
  All sound on the raspberry pi is 1 bit PWM.
  - anonymousiam 6y ago
    (Unless you're using the HDMI sound channel.)

chillingeffect 6y ago

Even for a sound chip, analog was unusual. a lot of the arcade games from that era and for another 10-15 years would often dedicate whole CPUs, such as Z80s and 6809s to sound. e.g. run some classics in MAME and it displays the sound chip(s) used in each game. Some of them have as many or more cycles used than the game CPU :) the tradeoff this chip made was fewer transistors and cost in exchange for not being very music, or able to be tuned well. it really was more a sound effect chip then a music chip.

zerocrates 6y ago
This has me thinking of the era when the LaserWriter printer had a significantly faster CPU and more RAM than the Macs it was paired with. The complexities of interfacing with the analog world...
- jecel 6y ago
  The LaserWriter had to run the Postscript interpreter, which required a lot more CPU power than just generating Postscript files like the Mac did.

tenebrisalietum 6y ago

The Apple II has a single register that toggles the voltage to a speaker, allowing 100% CPU-driven construction of any square wave you want. I think other systems did something similar on cassette ports. That's an example of the power available to an 8-bit class CPU without any extra hardware - you can do a lot with PWM and high-frequency attenuation and such but definitely limited.

joezydeco 6y ago
1-bit sound construction was discussed earlier this week on HN: https://news.ycombinator.com/item?id=23144469 https://news.ycombinator.com/item?id=23144469
ddingus 6y ago
A lot of game sounds were found by placing writes to the speaker in various game event loops. The result was lean sounds, but they also made a lot of sense.
londons_explore 6y ago
All sound on the raspberry pi is 1 bit PWM.
- anonymousiam 6y ago
  (Unless you're using the HDMI sound channel.)