diff --git a/doc/7-systems/opz.md b/doc/7-systems/opz.md
index dc7008085..cb374693f 100644
--- a/doc/7-systems/opz.md
+++ b/doc/7-systems/opz.md
@@ -113,6 +113,11 @@ no plans have been made for TX81Z MIDI passthrough, because:
 - `5Dxx`: **set D2R/SR of operator 2.**
 - `5Exx`: **set D2R/SR of operator 3.**
 - `5Fxx`: **set D2R/SR of operator 4.**
+- `61xx`: **set algorithm** (0 to 7).
+- `62xx`: **set LFO FM depth** (0 to 7).
+- `63xx`: **set LFO AM depth** (0 to 3).
+- `64xx`: **set LFO2 FM depth** (0 to 7).
+- `65xx`: **set LFO2 AM depth** (0 to 3).
 
 ## info
 
diff --git a/doc/7-systems/ym2151.md b/doc/7-systems/ym2151.md
index cadaf6b79..984184730 100644
--- a/doc/7-systems/ym2151.md
+++ b/doc/7-systems/ym2151.md
@@ -75,6 +75,9 @@ in most arcade boards the chip was used in combination with a PCM chip, like [Se
     - for example, having only OP2 and OP4 on would be 2 + 8 = 10, resulting in an `xy` value of `0A`.
   - if `x` is `1` to `4`, the effect targets that operator; `y` turns it off with a value of `0` and on with a value of `1`.
     - for example, the effect `6031` enables OP3.
+- `61xx`: **set algorithm** (0 to 7).
+- `62xx`: **set LFO FM depth** (0 to 7).
+- `63xx`: **set LFO AM depth** (0 to 3).
 
 ## info
 
diff --git a/doc/7-systems/ym2203.md b/doc/7-systems/ym2203.md
index b92290914..5a744db01 100644
--- a/doc/7-systems/ym2203.md
+++ b/doc/7-systems/ym2203.md
@@ -106,6 +106,9 @@ several variants of this chip were released as well, with more features.
     - for example, having only OP2 and OP4 on would be 2 + 8 = 10, resulting in an `xy` value of `0A`.
   - if `x` is `1` to `4`, the effect targets that operator; `y` turns it off with a value of `0` and on with a value of `1`.
     - for example, the effect `6031` enables OP3.
+- `61xx`: **set algorithm** (0 to 7).
+- `62xx`: **set LFO FM depth** (0 to 7).
+- `63xx`: **set LFO AM depth** (0 to 3).
 
 ## info
 
diff --git a/doc/7-systems/ym2608.md b/doc/7-systems/ym2608.md
index 570883569..63e0adc1d 100644
--- a/doc/7-systems/ym2608.md
+++ b/doc/7-systems/ym2608.md
@@ -106,7 +106,10 @@ the YM2610 (OPNB) and YM2610B chips are very similar to this one, but the built-
     - for example, having only OP2 and OP4 on would be 2 + 8 = 10, resulting in an `xy` value of `0A`.
   - if `x` is `1` to `4`, the effect targets that operator; `y` turns it off with a value of `0` and on with a value of `1`.
     - for example, the effect `6031` enables OP3.
-  
+- `61xx`: **set algorithm** (0 to 7).
+- `62xx`: **set LFO FM depth** (0 to 7).
+- `63xx`: **set LFO AM depth** (0 to 3).
+
 ## info
 
 this chip uses the [FM (OPN)](../4-instrument/fm-opn.md), [AY-3-8910/SSG](../4-instrument/ay8910.md), [ADPCM-A](../4-instrument/adpcm-a.md) and [ADPCM-B](../4-instrument/adpcm-b.md) instrument editors.
diff --git a/doc/7-systems/ym2610.md b/doc/7-systems/ym2610.md
index d8279e833..a32cdf0c2 100644
--- a/doc/7-systems/ym2610.md
+++ b/doc/7-systems/ym2610.md
@@ -104,6 +104,9 @@ its soundchip is a 4-in-1: 4ch 4-op FM, YM2149 (AY-3-8910 clone) and [2 differen
     - for example, having only OP2 and OP4 on would be 2 + 8 = 10, resulting in an `xy` value of `0A`.
   - if `x` is `1` to `4`, the effect targets that operator; `y` turns it off with a value of `0` and on with a value of `1`.
     - for example, the effect `6031` enables OP3.
+- `61xx`: **set algorithm** (0 to 7).
+- `62xx`: **set LFO FM depth** (0 to 7).
+- `63xx`: **set LFO AM depth** (0 to 3).
 
 ## info
 
diff --git a/doc/7-systems/ym2610b.md b/doc/7-systems/ym2610b.md
index f9fd0017b..c7b91df6e 100644
--- a/doc/7-systems/ym2610b.md
+++ b/doc/7-systems/ym2610b.md
@@ -103,6 +103,9 @@ it is backward compatible with the original chip.
     - for example, having only OP2 and OP4 on would be 2 + 8 = 10, resulting in an `xy` value of `0A`.
   - if `x` is `1` to `4`, the effect targets that operator; `y` turns it off with a value of `0` and on with a value of `1`.
     - for example, the effect `6031` enables OP3.
+- `61xx`: **set algorithm** (0 to 7).
+- `62xx`: **set LFO FM depth** (0 to 7).
+- `63xx`: **set LFO AM depth** (0 to 3).
 
 ## info
 
diff --git a/doc/7-systems/ym2612.md b/doc/7-systems/ym2612.md
index c5c8da66f..0d584b231 100644
--- a/doc/7-systems/ym2612.md
+++ b/doc/7-systems/ym2612.md
@@ -74,6 +74,9 @@ Furnace also offers DualPCM, a Z80 driver that splits channel 6 into two individ
     - for example, having only OP2 and OP4 on would be 2 + 8 = 10, resulting in an `xy` value of `0A`.
   - if `x` is `1` to `4`, the effect targets that operator; `y` turns it off with a value of `0` and on with a value of `1`.
     - for example, the effect `6031` enables OP3.
+- `61xx`: **set algorithm** (0 to 7).
+- `62xx`: **set LFO FM depth** (0 to 7).
+- `63xx`: **set LFO AM depth** (0 to 3).
 
 ## info