furnace/papers/doc/7-systems/nes.md

# NES

the console from Nintendo that plays Super Mario Bros. and helped revive the agonizing video game market in the US during mid-80s.

also known as Famicom. It is a five-channel PSG: first two channels play pulse wave with three different duty cycles, third is a fixed-volume triangle channel, fourth is a noise channel (can work in both pseudo-random and periodic modes) and  fifth is a (D)PCM sample channel

# effects

- `12xx`: set duty cycle or noise mode of channel.
  - may be 0-3 for the pulse channels and 0-1 for the noise channel.
- `13xy`: setup sweep up.
  - `x` is the time.
  - `y` is the shift.
  - set to 0 to disable it.
- `14xy`: setup sweep down.
  - `x` is the time.
  - `y` is the shift.
  - set to 0 to disable it.
update documentation 2022-01-16 06:10:43 +00:00			`# NES`

			`the console from Nintendo that plays Super Mario Bros. and helped revive the agonizing video game market in the US during mid-80s.`

somewhat improved system descriptions 2022-03-26 18:55:20 +00:00			`also known as Famicom. It is a five-channel PSG: first two channels play pulse wave with three different duty cycles, third is a fixed-volume triangle channel, fourth is a noise channel (can work in both pseudo-random and periodic modes) and fifth is a (D)PCM sample channel`
update documentation 2022-01-16 06:10:43 +00:00
			`# effects`

			- `12xx`: set duty cycle or noise mode of channel.
			`- may be 0-3 for the pulse channels and 0-1 for the noise channel.`
NES: add hardware sweep effect 2022-02-01 23:28:48 +00:00			- `13xy`: setup sweep up.
			- `x` is the time.
			- `y` is the shift.
			`- set to 0 to disable it.`
			- `14xy`: setup sweep down.
			- `x` is the time.
			- `y` is the shift.
somewhat improved system descriptions 2022-03-26 18:55:20 +00:00			`- set to 0 to disable it.`