diff --git a/papers/doc/7-systems/ym2203.md b/papers/doc/7-systems/ym2203.md new file mode 100644 index 00000000..18f051e8 --- /dev/null +++ b/papers/doc/7-systems/ym2203.md @@ -0,0 +1,101 @@ +# Yamaha YM2203 (OPN) + +a cost-reduced version of the YM2151 (OPM). +it only has 3 FM channels instead of 8 and removes the LFO. + +however it does contain an AY/SSG part which provides 3 channels of square wave with noise and envelope. + +this chip was used in the PC-88/PC-98 series of computers, and in some arcade boards. + +several variants of this chip were released as well, with more features. + +# effects + +- `11xx`: set feedback of channel. +- `12xx`: set operator 1 level. +- `13xx`: set operator 2 level. +- `14xx`: set operator 3 level. +- `15xx`: set operator 4 level. +- `16xy`: set multiplier of operator. + - `x` is the operator (1-4). + - `y` is the mutliplier. +- `18xx`: toggle extended channel 3 mode. + - 0 disables it and 1 enables it. + - only in extended channel 3 system. +- `19xx`: set attack of all operators. +- `1Axx`: set attack of operator 1. +- `1Bxx`: set attack of operator 2. +- `1Cxx`: set attack of operator 3. +- `1Dxx`: set attack of operator 4. +- `20xx`: set SSG channel mode. `xx` may be one of the following: + - `00`: square + - `01`: noise + - `02`: square and noise + - `03`: nothing (apparently) + - `04`: envelope and square + - `05`: envelope and noise + - `06`: envelope and square and noise + - `07`: nothing +- `21xx`: set noise frequency. `xx` is a value between 00 and 1F. +- `22xy`: set envelope mode. + - `x` sets the envelope shape, which may be one of the following: + - `0: \___` decay + - `4: /___` attack once + - `8: \\\\` saw + - `9: \___` decay + - `A: \/\/` inverse obelisco + - `B: \¯¯¯` decay once + - `C: ////` inverse saw + - `D: /¯¯¯` attack + - `E: /\/\` obelisco + - `F: /___` attack once + - if `y` is 1 then the envelope will affect this channel. +- `23xx`: set envelope period low byte. +- `24xx`: set envelope period high byte. +- `25xx`: slide envelope period up. +- `26xx`: slide envelope period down. +- `29xy`: enable SSG auto-envelope mode. + - in this mode the envelope period is set to the channel's notes, multiplied by a fraction. + - `x` is the numerator. + - `y` is the denominator. + - if `x` or `y` are 0 this will disable auto-envelope mode. +- `30xx`: enable envelope hard reset. + - this works by inserting a quick release and tiny delay before a new note. +- `50xy`: set AM of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` determines whether AM is on. +- `51xy` set SL of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value. +- `52xy` set RR of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value. +- `53xy` set DT of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value: + - 0: +0 + - 1: +1 + - 2: +2 + - 3: +3 + - 4: -0 + - 5: -3 + - 6: -2 + - 7: -1 +- `54xy` set RS of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value. +- `55xy` set SSG-EG of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value (0-8). + - values between 0 and 7 set SSG-EG. + - value 8 disables it. +- `56xx`: set DR of all operators. +- `57xx`: set DR of operator 1. +- `58xx`: set DR of operator 2. +- `59xx`: set DR of operator 3. +- `5Axx`: set DR of operator 4. +- `5Bxx`: set D2R/SR of all operators. +- `5Cxx`: set D2R/SR of operator 1. +- `5Dxx`: set D2R/SR of operator 2. +- `5Exx`: set D2R/SR of operator 3. +- `5Fxx`: set D2R/SR of operator 4. diff --git a/papers/doc/7-systems/ym2608.md b/papers/doc/7-systems/ym2608.md new file mode 100644 index 00000000..51720d1b --- /dev/null +++ b/papers/doc/7-systems/ym2608.md @@ -0,0 +1,101 @@ +# Yamaha YM2608 (OPNA) + +like YM2203, but with twice the FM channels, an ADPCM channel and built-in drums ("rhythm")! + +it was one of the available sound chips for the PC-98 series of computers. + +the YM2610 (OPNB) and YM2610B chips are very similar to this one, but the built-in drums have been replaced with 6 sample channels. + +# effects + +- `10xy`: set LFO parameters. + - `x` toggles the LFO. + - `y` sets its speed. +- `11xx`: set feedback of channel. +- `12xx`: set operator 1 level. +- `13xx`: set operator 2 level. +- `14xx`: set operator 3 level. +- `15xx`: set operator 4 level. +- `16xy`: set multiplier of operator. + - `x` is the operator (1-4). + - `y` is the mutliplier. +- `18xx`: toggle extended channel 3 mode. + - 0 disables it and 1 enables it. + - only in extended channel 3 system. +- `19xx`: set attack of all operators. +- `1Axx`: set attack of operator 1. +- `1Bxx`: set attack of operator 2. +- `1Cxx`: set attack of operator 3. +- `1Dxx`: set attack of operator 4. +- `20xx`: set SSG channel mode. `xx` may be one of the following: + - `00`: square + - `01`: noise + - `02`: square and noise + - `03`: nothing (apparently) + - `04`: envelope and square + - `05`: envelope and noise + - `06`: envelope and square and noise + - `07`: nothing +- `21xx`: set noise frequency. `xx` is a value between 00 and 1F. +- `22xy`: set envelope mode. + - `x` sets the envelope shape, which may be one of the following: + - `0: \___` decay + - `4: /___` attack once + - `8: \\\\` saw + - `9: \___` decay + - `A: \/\/` inverse obelisco + - `B: \¯¯¯` decay once + - `C: ////` inverse saw + - `D: /¯¯¯` attack + - `E: /\/\` obelisco + - `F: /___` attack once + - if `y` is 1 then the envelope will affect this channel. +- `23xx`: set envelope period low byte. +- `24xx`: set envelope period high byte. +- `25xx`: slide envelope period up. +- `26xx`: slide envelope period down. +- `29xy`: enable SSG auto-envelope mode. + - in this mode the envelope period is set to the channel's notes, multiplied by a fraction. + - `x` is the numerator. + - `y` is the denominator. + - if `x` or `y` are 0 this will disable auto-envelope mode. +- `30xx`: enable envelope hard reset. + - this works by inserting a quick release and tiny delay before a new note. +- `50xy`: set AM of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` determines whether AM is on. +- `51xy` set SL of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value. +- `52xy` set RR of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value. +- `53xy` set DT of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value: + - 0: +0 + - 1: +1 + - 2: +2 + - 3: +3 + - 4: -0 + - 5: -3 + - 6: -2 + - 7: -1 +- `54xy` set RS of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value. +- `55xy` set SSG-EG of operator. + - `x` is the operator (1-4). a value of 0 means "all operators". + - `y` is the value (0-8). + - values between 0 and 7 set SSG-EG. + - value 8 disables it. +- `56xx`: set DR of all operators. +- `57xx`: set DR of operator 1. +- `58xx`: set DR of operator 2. +- `59xx`: set DR of operator 3. +- `5Axx`: set DR of operator 4. +- `5Bxx`: set D2R/SR of all operators. +- `5Cxx`: set D2R/SR of operator 1. +- `5Dxx`: set D2R/SR of operator 2. +- `5Exx`: set D2R/SR of operator 3. +- `5Fxx`: set D2R/SR of operator 4. diff --git a/papers/doc/7-systems/ym2610b.md b/papers/doc/7-systems/ym2610b.md index 17f27455..4133681f 100644 --- a/papers/doc/7-systems/ym2610b.md +++ b/papers/doc/7-systems/ym2610b.md @@ -16,9 +16,9 @@ it is backward compatible with the original chip. - `16xy`: set multiplier of operator. - `x` is the operator (1-4). - `y` is the mutliplier. -- `18xx`: toggle extended channel 2 mode. +- `18xx`: toggle extended channel 3 mode. - 0 disables it and 1 enables it. - - only in extended channel 2 system. + - only in extended channel 3 system. - `19xx`: set attack of all operators. - `1Axx`: set attack of operator 1. - `1Bxx`: set attack of operator 2. @@ -95,4 +95,4 @@ it is backward compatible with the original chip. - `5Cxx`: set D2R/SR of operator 1. - `5Dxx`: set D2R/SR of operator 2. - `5Exx`: set D2R/SR of operator 3. -- `5Fxx`: set D2R/SR of operator 4. \ No newline at end of file +- `5Fxx`: set D2R/SR of operator 4.