diff --git a/erlang/apps/sim/src/sim_boolean.erl b/erlang/apps/sim/src/sim_boolean.erl
index a441ae7..00f52cd 100644
--- a/erlang/apps/sim/src/sim_boolean.erl
+++ b/erlang/apps/sim/src/sim_boolean.erl
@@ -48,6 +48,7 @@
         , handle_IORB/4
         , handle_IORI/4
         , handle_IORM/4
+        , handle_SETCA/4
         , handle_SETMB/4
         , handle_SETMI/4
         , handle_SETMM/4
@@ -513,6 +514,16 @@ handle_EQVB(Core, Mem, IR, EA) ->
                           fun(Core1, Mem1) -> handle_EQVB(Core1, Mem1, IR, EA) end)
   end.
 
+%% SETCA - Set to Complement of AC
+
+-spec handle_SETCA(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_SETCA(Core, Mem, IR, _EA) ->
+  AC = IR band 8#17,
+  CA = sim_core:get_ac(Core, AC),
+  Word = (bnot CA) band ((1 bsl 36) - 1),
+  sim_core:next_pc(sim_core:set_ac(Core, AC, Word), Mem).
+
 %% Miscellaneous ===============================================================
 
 ea_address(#ea{section = Section, offset = Offset}) ->
diff --git a/erlang/apps/sim/src/sim_core.erl b/erlang/apps/sim/src/sim_core.erl
index 9f63d86..2aafadc 100644
--- a/erlang/apps/sim/src/sim_core.erl
+++ b/erlang/apps/sim/src/sim_core.erl
@@ -293,6 +293,7 @@ dispatch(Core, Mem, IR, EA) ->
     8#445 -> sim_boolean:handle_EQVI(Core, Mem, IR, EA);
     8#446 -> sim_boolean:handle_EQVM(Core, Mem, IR, EA);
     8#447 -> sim_boolean:handle_EQVB(Core, Mem, IR, EA);
+    8#450 -> sim_boolean:handle_SETCA(Core, Mem, IR, EA);
     _ ->
       PC = (Core#core.pc_section bsl 18) bor Core#core.pc_offset,
       {Core, Mem, {error, {?MODULE, {dispatch, PC, IR, EA}}}}
diff --git a/erlang/apps/sim/test/sim_boolean_tests.erl b/erlang/apps/sim/test/sim_boolean_tests.erl
index 9e23bb2..1f59fa9 100644
--- a/erlang/apps/sim/test/sim_boolean_tests.erl
+++ b/erlang/apps/sim/test/sim_boolean_tests.erl
@@ -84,6 +84,7 @@
 -define(OP_EQVI, 8#445).
 -define(OP_EQVM, 8#446).
 -define(OP_EQVB, 8#447).
+-define(OP_SETCA, 8#450).
 
 %% 2.4 Boolean Functions =======================================================
 
@@ -574,6 +575,18 @@ eqvb_test() ->
          , {#ea{section = 1, offset = 1, islocal = false}, ?COMMA2(-1, 8#343434)} % AC1 = -1,,343434
          ]).
 
+%% SETCA - Set to Complement of AC
+
+setca_test() ->
+  Prog =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 8#707070)} % 1,,100/ MOVEI 1,707070
+    , {1, 8#101, ?INSN(?OP_SETCA, 1, 0, 0, 0)}        % 1,,101/ SETCA 1,
+    , {1, 8#102, ?INSN_INVALID}                       % 1,,102/ <invalid>
+    ],
+  expect(Prog, [], {1, 8#102}, ?DEFAULT_FLAGS,
+         [ {#ea{section = 1, offset = 1, islocal = false}, ?COMMA2(-1, 8#070707)} % AC1 = -1,,070707
+         ]).
+
 %% Common code to run short sequences ==========================================
 
 expect(Prog, ACs, ExpectedPC, ExpectedFlags, ExpectedEs) ->