diff --git a/doc/README.md b/doc/README.md
index 4ce663a..b3cc13c 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -288,26 +288,3 @@ GVerb algorithm from SWH plugins.
  - drylevel (dB): -70..0, default 0
  - earlylevel (dB): -70..0, default 0
  - taillevel (dB): -70..0, default -17.5
-
-## `invert split index`
-
-> A utility plugin that inverts the signal, also (wrongly) known as a 180 degree phase shift.
-
-## `tapedelay split index`
-
-**TODO:** gives 0 output
-
-> Correctly models the tape motion and some of the smear effect, there is no simulation fo the head saturation yet, as I don't have a good model of it. When I get one I will add it.
-
-> The way the tape accelerates and decelerates gives a nicer delay effect for many purposes.
-
- - speed (inches/sec, 1=normal): 0..10, default 1
- - da\_db (dry level, dB): -90..0, default -90
- - t1d (tap 1 distance, inches): 0..4, default 0
- - t1a\_db (tap 1 level, dB): -90..0, default 0
- - t2d (tap 2 distance, inches): 0..4, default 1
- - t2a\_db (tap 2 level, dB): -90..0, default -90
- - t3d (tap 3 distance, inches): 0..4, default 2
- - t3a\_db (tap 3 level, dB): -90..0, default -90
- - t4d (tap 4 distance, inches): 0..4, default 3
- - t4a\_db (tap 4 level, dB): -90..0, default -90
diff --git a/examples/invert.scri b/examples/invert.scri
deleted file mode 100644
index bd7b695..0000000
--- a/examples/invert.scri
+++ /dev/null
@@ -1,3 +0,0 @@
-load :0;
-invert 3 1;
-quicksave;
diff --git a/examples/tapedelay.scri b/examples/tapedelay.scri
deleted file mode 100644
index 4b5d8c0..0000000
--- a/examples/tapedelay.scri
+++ /dev/null
@@ -1,3 +0,0 @@
-load :0;
-tapedelay 3 1 1 -90 0 0 1 -90 2 -90 3 -90;
-quicksave;
diff --git a/src/lang.zig b/src/lang.zig
index dd91bd6..60bf549 100644
--- a/src/lang.zig
+++ b/src/lang.zig
@@ -36,8 +36,6 @@ pub const CommandType = enum {
     ThruZero,
     Foverdrive,
     Gverb,
-    Invert,
-    TapeDelay,
 
     Noise,
     WildNoise,
@@ -203,8 +201,6 @@ pub const Lang = struct {
         _ = try self.keywords.put("thruzero", .ThruZero);
         _ = try self.keywords.put("foverdrive", .Foverdrive);
         _ = try self.keywords.put("gverb", .Gverb);
-        _ = try self.keywords.put("invert", .Invert);
-        _ = try self.keywords.put("tapedelay", .TapeDelay);
 
         // custom implementations (not lv2)
         _ = try self.keywords.put("noise", .Noise);
diff --git a/src/printer.zig b/src/printer.zig
index 8491328..1fb6c68 100644
--- a/src/printer.zig
+++ b/src/printer.zig
@@ -30,8 +30,6 @@ pub fn printList(list: langs.CommandList, stream: var) !void {
             .ThruZero => "thruzero",
             .Foverdrive => "foverdrive",
             .Gverb => "gverb",
-            .Invert => "invert",
-            .TapeDelay => "tapedelay",
 
             .Noise => "noise",
             .WildNoise => "wildnoise",
diff --git a/src/runner.zig b/src/runner.zig
index 7bc870d..451dac5 100644
--- a/src/runner.zig
+++ b/src/runner.zig
@@ -344,16 +344,6 @@ pub const Runner = struct {
         try image.runPlugin("http://plugin.org.uk/swh-plugins/gverb", pos, params);
     }
 
-    fn invertCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/inv", pos, params);
-    }
-
-    fn tapedelayCmd(self: *Runner, pos: Position, params: ParamList) !void {
-        var image = try self.getImage();
-        try image.runPlugin("http://plugin.org.uk/swh-plugins/tapeDelay", pos, params);
-    }
-
     fn runCommand(self: *Runner, cmd: *lang.Command) !void {
         var params = ParamList.init(self.allocator);
         defer params.deinit();
@@ -639,31 +629,6 @@ pub const Runner = struct {
                 try self.gverbCmd(pos, params);
             },
 
-            .Invert => {
-                const pos = try cmd.consumePosition();
-                try self.gverbCmd(pos, params);
-            },
-
-            .TapeDelay => {
-                const pos = try cmd.consumePosition();
-                try cmd.appendParam(&params, "speed");
-                try cmd.appendParam(&params, "da_db");
-
-                try cmd.appendParam(&params, "t1d");
-                try cmd.appendParam(&params, "t1a_db");
-
-                try cmd.appendParam(&params, "t2d");
-                try cmd.appendParam(&params, "t2a_db");
-
-                try cmd.appendParam(&params, "t3d");
-                try cmd.appendParam(&params, "t3a_db");
-
-                try cmd.appendParam(&params, "t4d");
-                try cmd.appendParam(&params, "t4a_db");
-
-                try self.tapedelayCmd(pos, params);
-            },
-
             else => blk: {
                 std.debug.warn("Unsupported command: {}\n", .{cmd.command});
                 break :blk RunError.UnknownCommand;