99 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			99 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| # Taito Arcade/Yamaha YM2610B
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| 
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| YM2610B is basically YM2610 with 2 extra FM channels used at some 90s Taito arcade hardware.
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| it is backward compatible with the original chip.
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| 
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| # effects
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| 
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| - `10xy`: **set LFO parameters.**
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|   - `x` toggles the LFO.
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|   - `y` sets its speed.
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| - `11xx`: **set feedback of channel.**
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| - `12xx`: **set operator 1 level.**
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| - `13xx`: **set operator 2 level.**
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| - `14xx`: **set operator 3 level.**
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| - `15xx`: **set operator 4 level.**
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| - `16xy`: **set multiplier of operator.**
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|   - `x` is the operator (1-4).
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|   - `y` is the multiplier.
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| - `18xx`: **toggle extended channel 3 mode.**
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|   - 0 disables it and 1 enables it.
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|   - only in extended channel 3 chip.
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| - `19xx`: **set attack of all operators.**
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| - `1Axx`: **set attack of operator 1.**
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| - `1Bxx`: **set attack of operator 2.**
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| - `1Cxx`: **set attack of operator 3.**
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| - `1Dxx`: **set attack of operator 4.**
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| - `20xx`: **set SSG channel mode.**
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|   - `00`: square
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|   - `01`: noise
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|   - `02`: square and noise
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|   - `03`: nothing (apparently)
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|   - `04`: envelope and square
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|   - `05`: envelope and noise
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|   - `06`: envelope and square and noise
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|   - `07`: nothing
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| - `21xx`: **set noise frequency.** range is `00` to `1F`.
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| - `22xy`: **set envelope mode.**
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|   - `x` sets the envelope shape, which may be one of the following:
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|     - `0`:` \___` decay
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|     - `4`:` /___` attack once
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|     - `8`:` \\\\` saw
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|     - `9`:` \___` decay
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|     - `A`:` \/\/` inverse obelisco
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|     - `B`:` \¯¯¯` decay once
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|     - `C`:` ////` inverse saw
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|     - `D`:` /¯¯¯` attack
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|     - `E`:` /\/\` obelisco
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|     - `F`:` /___` attack once
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|   - if `y` is 1 then the envelope will affect this channel.
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| - `23xx`: **set envelope period low byte.**
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| - `24xx`: **set envelope period high byte.**
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| - `25xx`: **slide envelope period up.**
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| - `26xx`: **slide envelope period down.**
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| - `29xy`: **enable SSG auto-envelope mode.**
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|   - in this mode the envelope period is set to the channel's notes, multiplied by a fraction.
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|   - `x` is the numerator.
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|   - `y` is the denominator.
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|   - if `x` or `y` are 0 this will disable auto-envelope mode.
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| - `30xx`: **enable envelope hard reset.**
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|   - this works by inserting a quick release and tiny delay before a new note.
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| - `50xy`: **set AM of operator.**
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|   - `x` is the operator (1-4). a value of 0 means "all operators".
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|   - `y` determines whether AM is on.
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| - `51xy`: **set SL of operator.**
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|   - `x` is the operator (1-4). a value of 0 means "all operators".
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|   - `y` is the value.
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| - `52xy`: **set RR of operator.**
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|   - `x` is the operator (1-4). a value of 0 means "all operators".
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|   - `y` is the value.
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| - `53xy`: **set DT of operator.**
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|   - `x` is the operator (1-4). a value of 0 means "all operators".
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|   - `y` is the value:
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|     - `0`: +0
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|     - `1`: +1
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|     - `2`: +2
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|     - `3`: +3
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|     - `4`: -0
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|     - `5`: -3
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|     - `6`: -2
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|     - `7`: -1
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| - `54xy`: **set RS of operator.**
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|   - `x` is the operator (1-4). a value of 0 means "all operators".
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|   - `y` is the value.
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| - `55xy`: **set SSG-EG of operator.**
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|   - `x` is the operator (1-4). a value of 0 means "all operators".
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|   - `y` is the value (0-8).
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|     - values between 0 and 7 set SSG-EG.
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|     - value 8 disables it.
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| - `56xx`: **set DR of all operators.**
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| - `57xx`: **set DR of operator 1.**
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| - `58xx`: **set DR of operator 2.**
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| - `59xx`: **set DR of operator 3.**
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| - `5Axx`: **set DR of operator 4.**
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| - `5Bxx`: **set D2R/SR of all operators.**
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| - `5Cxx`: **set D2R/SR of operator 1.**
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| - `5Dxx`: **set D2R/SR of operator 2.**
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| - `5Exx`: **set D2R/SR of operator 3.**
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| - `5Fxx`: **set D2R/SR of operator 4.**
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