diff --git a/erlang/apps/sim/src/sim_arithmetic.erl b/erlang/apps/sim/src/sim_arithmetic.erl
index 37fc5cd..5d3f63e 100644
--- a/erlang/apps/sim/src/sim_arithmetic.erl
+++ b/erlang/apps/sim/src/sim_arithmetic.erl
@@ -71,6 +71,14 @@
         , handle_SKIPL/4
         , handle_SKIPLE/4
         , handle_SKIPN/4
+        , handle_SOJ/4
+        , handle_SOJA/4
+        , handle_SOJE/4
+        , handle_SOJG/4
+        , handle_SOJGE/4
+        , handle_SOJL/4
+        , handle_SOJLE/4
+        , handle_SOJN/4
         ]).
 
 -include("sim_core.hrl").
@@ -656,6 +664,72 @@ handle_AOSG(Core, Mem, IR, EA, Word, Flags) ->
                           fun(Core1, Mem1) -> ?FUNCTION_NAME(Core1, Mem1, IR, EA, Word, Flags) end)
   end.
 
+%% SOJ - Subtract One from AC and Jump if Condition Satisfied
+
+-spec handle_SOJ(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_SOJ(Core, Mem, IR, _EA) ->
+  AC = IR band 8#17,
+  CA = sim_core:get_ac(Core, AC),
+  {Word, Flags} = sub1(CA),
+  sim_core:next_pc(sim_core:set_flags(sim_core:set_ac(Core, AC, Word), Flags), Mem).
+
+-spec handle_SOJL(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_SOJL(Core, Mem, IR, EA) ->
+  AC = IR band 8#17,
+  CA = sim_core:get_ac(Core, AC),
+  {Word, Flags} = sub1(CA),
+  jump_if_L(sim_core:set_flags(sim_core:set_ac(Core, AC, Word), Flags), Mem, Word, EA).
+
+-spec handle_SOJE(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_SOJE(Core, Mem, IR, EA) ->
+  AC = IR band 8#17,
+  CA = sim_core:get_ac(Core, AC),
+  {Word, Flags} = sub1(CA),
+  jump_if_E(sim_core:set_flags(sim_core:set_ac(Core, AC, Word), Flags), Mem, Word, EA).
+
+-spec handle_SOJLE(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_SOJLE(Core, Mem, IR, EA) ->
+  AC = IR band 8#17,
+  CA = sim_core:get_ac(Core, AC),
+  {Word, Flags} = sub1(CA),
+  jump_if_LE(sim_core:set_flags(sim_core:set_ac(Core, AC, Word), Flags), Mem, Word, EA).
+
+-spec handle_SOJA(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_SOJA(Core, Mem, IR, EA) ->
+  AC = IR band 8#17,
+  CA = sim_core:get_ac(Core, AC),
+  {Word, Flags} = sub1(CA),
+  jump(sim_core:set_flags(sim_core:set_ac(Core, AC, Word), Flags), Mem, EA).
+
+-spec handle_SOJGE(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_SOJGE(Core, Mem, IR, EA) ->
+  AC = IR band 8#17,
+  CA = sim_core:get_ac(Core, AC),
+  {Word, Flags} = sub1(CA),
+  jump_if_GE(sim_core:set_flags(sim_core:set_ac(Core, AC, Word), Flags), Mem, Word, EA).
+
+-spec handle_SOJN(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_SOJN(Core, Mem, IR, EA) ->
+  AC = IR band 8#17,
+  CA = sim_core:get_ac(Core, AC),
+  {Word, Flags} = sub1(CA),
+  jump_if_N(sim_core:set_flags(sim_core:set_ac(Core, AC, Word), Flags), Mem, Word, EA).
+
+-spec handle_SOJG(#core{}, sim_mem:mem(), IR :: word(), #ea{})
+      -> {#core{}, sim_mem:mem(), {ok, integer()} | {error, {module(), term()}}}.
+handle_SOJG(Core, Mem, IR, EA) ->
+  AC = IR band 8#17,
+  CA = sim_core:get_ac(Core, AC),
+  {Word, Flags} = sub1(CA),
+  jump_if_G(sim_core:set_flags(sim_core:set_ac(Core, AC, Word), Flags), Mem, Word, EA).
+
 %% Miscellaneous ===============================================================
 
 jump_if_E(Core, Mem, X, EA) ->
@@ -735,6 +809,21 @@ add1(Word) ->
     end,
   {Add1, Flags}.
 
+sub1(Word) ->
+  Sub1 = (Word - 1) band ((1 bsl 36) - 1),
+  Flags =
+    case Sub1 of
+      8#377777777777 -> % -2^35 - 1
+        (1 bsl ?PDP10_PF_TRAP_1) bor
+        (1 bsl ?PDP10_PF_OVERFLOW) bor
+        (1 bsl ?PDP10_PF_CARRY_0);
+      8#777777777777 -> % 0 - 1
+        0;
+      _ -> % "any other non-zero number" - 1
+        (1 bsl ?PDP10_PF_CARRY_0) bor (1 bsl ?PDP10_PF_CARRY_1)
+    end,
+  {Sub1, Flags}.
+
 %% Sign-extend a uint36_t() to the full width of its representation type.
 -spec sext36(uint36_t()) -> integer().
 sext36(X) ->
diff --git a/erlang/apps/sim/src/sim_core.erl b/erlang/apps/sim/src/sim_core.erl
index b20703c..871f8a7 100644
--- a/erlang/apps/sim/src/sim_core.erl
+++ b/erlang/apps/sim/src/sim_core.erl
@@ -336,6 +336,14 @@ dispatch(Core, Mem, IR, EA) ->
     8#355 -> sim_arithmetic:handle_AOSGE(Core, Mem, IR, EA);
     8#356 -> sim_arithmetic:handle_AOSN(Core, Mem, IR, EA);
     8#357 -> sim_arithmetic:handle_AOSG(Core, Mem, IR, EA);
+    8#360 -> sim_arithmetic:handle_SOJ(Core, Mem, IR, EA);
+    8#361 -> sim_arithmetic:handle_SOJL(Core, Mem, IR, EA);
+    8#362 -> sim_arithmetic:handle_SOJE(Core, Mem, IR, EA);
+    8#363 -> sim_arithmetic:handle_SOJLE(Core, Mem, IR, EA);
+    8#364 -> sim_arithmetic:handle_SOJA(Core, Mem, IR, EA);
+    8#365 -> sim_arithmetic:handle_SOJGE(Core, Mem, IR, EA);
+    8#366 -> sim_arithmetic:handle_SOJN(Core, Mem, IR, EA);
+    8#367 -> sim_arithmetic:handle_SOJG(Core, Mem, IR, EA);
     8#400 -> sim_boolean:handle_SETZ(Core, Mem, IR, EA);
     8#401 -> sim_boolean:handle_SETZ(Core, Mem, IR, EA); % SETZI = SETZ
     8#402 -> sim_boolean:handle_SETZM(Core, Mem, IR, EA);
diff --git a/erlang/apps/sim/test/sim_arithmetic_tests.erl b/erlang/apps/sim/test/sim_arithmetic_tests.erl
index f97727d..8d69744 100644
--- a/erlang/apps/sim/test/sim_arithmetic_tests.erl
+++ b/erlang/apps/sim/test/sim_arithmetic_tests.erl
@@ -103,6 +103,14 @@
 -define(OP_AOSGE,  8#355).
 -define(OP_AOSN,   8#356).
 -define(OP_AOSG,   8#357).
+-define(OP_SOJ,    8#360).
+-define(OP_SOJL,   8#361).
+-define(OP_SOJE,   8#362).
+-define(OP_SOJLE,  8#363).
+-define(OP_SOJA,   8#364).
+-define(OP_SOJGE,  8#365).
+-define(OP_SOJN,   8#366).
+-define(OP_SOJG,   8#367).
 
 %% 2.6.1 Add One to Both Halves of AC and Jump =================================
 
@@ -1000,6 +1008,151 @@ aosg_test() ->
          [ {?EA(1, 8#150), ?LOW36(-1)}               % C(1,,150) = -1
          , {?AC(1), ?LOW36(-1)}]).                   % AC(1) = -1
 
+%% SOJ - Subtract One from AC and Jump if Condition Satisfied
+
+soj_test() ->
+  Prog =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 2)}       % 1,,100/ MOVEI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJ, 1, 0, 0, 0)}         % 1,,101/ SOJ 1,
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    ],
+  expect(Prog, [], {1, 8#102}, ?CARRY_FLAGS,         % no jump, carry 0 and 1
+         [ {?AC(1), 1}]).                            % AC(1) = 1
+
+sojl_test() ->
+  Prog1 =
+    [ {1, 8#100, ?INSN(?OP_MOVNI, 1, 0, 0, 2)}       % 1,,100/ MOVNI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJL, 1, 0, 0, 8#103)}    % 1,,101/ SOJL 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog1, [], {1, 8#103}, ?CARRY_FLAGS,        % jump, carry 0 and 1
+         [ {?AC(1), ?LOW36(-3)}]),                   % AC(1) = -3
+  Prog2 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 2)}       % 1,,100/ MOVEI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJL, 1, 0, 0, 8#103)}    % 1,,101/ SOJL 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog2, [], {1, 8#102}, ?CARRY_FLAGS,        % no jump, carry 0 and 1
+         [ {?AC(1), 1}]).                            % AC(1) = 1
+
+soje_test() ->
+  Prog1 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 1)}       % 1,,100/ MOVEI 1,1
+    , {1, 8#101, ?INSN(?OP_SOJE, 1, 0, 0, 8#103)}    % 1,,101/ SOJE 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog1, [], {1, 8#103}, ?CARRY_FLAGS,        % jump, carry 0 and 1
+         [ {?AC(1), 0}]),                            % AC(1) = 0
+  Prog2 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 2)}       % 1,,100/ MOVEI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJE, 1, 0, 0, 8#103)}    % 1,,101/ SOJE 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog2, [], {1, 8#102}, ?CARRY_FLAGS,        % no jump, carry 0 and 1
+         [ {?AC(1), 1}]).                            % AC(1) = 1
+
+sojle_test() ->
+  Prog1 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 0)}       % 1,,100/ MOVEI 1,0
+    , {1, 8#101, ?INSN(?OP_SOJLE, 1, 0, 0, 8#103)}   % 1,,101/ SOJLE 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog1, [], {1, 8#103}, ?DEFAULT_FLAGS,      % jump, no carry flags
+         [ {?AC(1), ?LOW36(-1)}]),                   % AC(1) = -1
+  Prog2 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 1)}       % 1,,100/ MOVEI 1,1
+    , {1, 8#101, ?INSN(?OP_SOJLE, 1, 0, 0, 8#103)}   % 1,,101/ SOJLE 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog2, [], {1, 8#103}, ?CARRY_FLAGS,        % jump, carry 0 and 1
+         [ {?AC(1), 0}]),                            % AC(1) = 0
+  Prog3 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 2)}       % 1,,100/ MOVEI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJLE, 1, 0, 0, 8#103)}   % 1,,101/ SOJLE 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog3, [], {1, 8#102}, ?CARRY_FLAGS,        % no jump, carry 0 and 1
+         [ {?AC(1), 1}]).                            % AC(1) = 1
+
+soja_test() ->
+  Prog =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 2)}       % 1,,100/ MOVEI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJA, 1, 0, 0, 8#103)}    % 1,,101/ SOJA 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog, [], {1, 8#103}, ?CARRY_FLAGS,         % jump, carry 0 and 1
+         [ {?AC(1), 1}]).                            % AC(1) = 1
+
+sojge_test() ->
+  Prog1 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 2)}       % 1,,100/ MOVEI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJGE, 1, 0, 0, 8#103)}   % 1,,101/ SOJGE 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog1, [], {1, 8#103}, ?CARRY_FLAGS,        % jump, carry 0 and 1
+         [ {?AC(1), 1}]),                            % AC(1) = 1
+  Prog2 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 1)}       % 1,,100/ MOVEI 1,1
+    , {1, 8#101, ?INSN(?OP_SOJGE, 1, 0, 0, 8#103)}   % 1,,101/ SOJGE 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog2, [], {1, 8#103}, ?CARRY_FLAGS,        % jump, carry 0 and 1
+         [ {?AC(1), 0}]),                            % AC(1) = 0
+  Prog3 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 0)}       % 1,,100/ MOVEI 1,0
+    , {1, 8#101, ?INSN(?OP_SOJGE, 1, 0, 0, 8#103)}   % 1,,101/ SOJGE 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog3, [], {1, 8#102}, ?DEFAULT_FLAGS,      % no jump, no carry flags
+         [ {?AC(1), ?LOW36(-1)}]).                   % AC(1) = -1
+
+sojn_test() ->
+  Prog1 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 2)}       % 1,,100/ MOVEI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJN, 1, 0, 0, 8#103)}    % 1,,101/ SOJN 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog1, [], {1, 8#103}, ?CARRY_FLAGS,        % jump, carry 0 and 1
+         [ {?AC(1), 1}]),                            % AC(1) = 1
+  Prog2 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 1)}       % 1,,100/ MOVEI 1,1
+    , {1, 8#101, ?INSN(?OP_SOJN, 1, 0, 0, 8#103)}    % 1,,101/ SOJN 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog2, [], {1, 8#102}, ?CARRY_FLAGS,        % no jump, carry 0 and 1
+         [ {?AC(1), 0}]).                            % AC(1) = 0
+
+sojg_test() ->
+  Prog1 =
+    [ {1, 8#100, ?INSN(?OP_MOVEI, 1, 0, 0, 2)}       % 1,,100/ MOVEI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJG, 1, 0, 0, 8#103)}    % 1,,101/ SOJG 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog1, [], {1, 8#103}, ?CARRY_FLAGS,        % jump, carry 0 and 1
+         [ {?AC(1), 1}]),                            % AC(1) = 1
+  Prog2 =
+    [ {1, 8#100, ?INSN(?OP_MOVNI, 1, 0, 0, 2)}       % 1,,100/ MOVNI 1,2
+    , {1, 8#101, ?INSN(?OP_SOJG, 1, 0, 0, 8#103)}    % 1,,101/ SOJG 1,103
+    , {1, 8#102, ?INSN_INVALID}                      % 1,,102/ <invalid>
+    , {1, 8#103, ?INSN_INVALID}                      % 1,,103/ <invalid>
+    ],
+  expect(Prog2, [], {1, 8#102}, ?CARRY_FLAGS,        % no jump, carry 0 and 1
+         [ {?AC(1), ?LOW36(-3)}]).                   % AC(1) = -3
+
 %% Common code to run short sequences ==========================================
 
 expect(Prog, ACs, ExpectedPC, ExpectedFlags, ExpectedEs) ->