diff --git a/papers/format.md b/papers/format.md
index dca4c0143..fc442e895 100644
--- a/papers/format.md
+++ b/papers/format.md
@@ -236,7 +236,7 @@ size | description
      |   - 0xd0: Namco C352 - 32 channels (UNAVAILABLE)
      |   - 0xd1: ESFM - 18 channels
      |   - 0xd2: Ensoniq ES5503 (hard pan) - 32 channels (UNAVAILABLE)
-     |   - 0xd4: PowerNoise - 4 channels (UNAVAILABLE)
+     |   - 0xd4: PowerNoise - 4 channels
      |   - 0xde: YM2610B extended - 19 channels
      |   - 0xe0: QSound - 19 channels
      |   - 0xfc: Pong - 1 channel
diff --git a/papers/newIns.md b/papers/newIns.md
index 8111ac4a4..341956c32 100644
--- a/papers/newIns.md
+++ b/papers/newIns.md
@@ -121,6 +121,9 @@ the following instrument types are available:
 - 52: TED
 - 53: C140
 - 54: C219
+- 55: ESFM
+- 56: PowerNoise (noise)
+- 57: PowerNoise (slope)
 
 the following feature codes are recognized:
 
@@ -146,6 +149,7 @@ the following feature codes are recognized:
 - `ES`: ES5506 ins data
 - `X1`: X1-010 ins data
 - `NE`: NES DPCM sample map data
+- `EF`: ESFM ins data
 - `EN`: end of features
   - if you find this feature code, stop reading the instrument.
   - it will usually appear only when there sample/wave lists.