diff --git a/.gitignore b/.gitignore
index 5c4e686..f34e038 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 *.out
 .cache/
-compile_commands.json
\ No newline at end of file
+compile_commands.json
+/TAGS
+/.gdb_history
diff --git a/build.sh b/build.sh
index b249881..f5635b1 100644
--- a/build.sh
+++ b/build.sh
@@ -2,7 +2,7 @@
 
 CFLAGS="-Wall -Wextra -Wpedantic -Wswitch-enum -Werror -std=c23 -ggdb"
 LDFLAGS="-lm -lraylib"
-SRC="src/sv.c src/vec.c src/program_iter.c src/main.c"
+SRC="src/sv.c src/vec.c src/program_iter.c src/simulation.c src/main.c"
 OUT="main.out"
 
 set -xe
diff --git a/src/main.c b/src/main.c
index b25f5a5..bfc9cae 100644
--- a/src/main.c
+++ b/src/main.c
@@ -15,55 +15,11 @@
 #include "vec.h"
 
 #include "program_iter.h"
-
-struct ProgramConcat
-{
-  sv_t A, B;
-  u8 tape[SIZEOF_PROGRAM * 2];
-};
+#include "simulation.h"
 
 #define WIDTH  800
 #define HEIGHT 600
 
-#define NUM_PROGRAMS_POW_2 10
-#define NUM_PROGRAMS       (1LU << NUM_PROGRAMS_POW_2)
-#define SIMULATION_SIZE    (SIZEOF_PROGRAM * NUM_PROGRAMS)
-struct Simulation
-{
-  char buffer[SIMULATION_SIZE];
-  u64 p1, p2;
-};
-
-void simulation_init(struct Simulation *sim)
-{
-  for (u64 i = 0; i < SIMULATION_SIZE / sizeof(u16); ++i)
-  {
-    ((u16 *)(sim->buffer))[i] = rand() % UINT16_MAX;
-  }
-}
-
-void simulation_pick(struct Simulation *sim)
-{
-  sim->p1 = rand() % (SIMULATION_SIZE / SIZEOF_PROGRAM);
-  sim->p2 = rand() % (SIMULATION_SIZE / SIZEOF_PROGRAM);
-  while (sim->p1 * 8 <= ((sim->p2 * 8) + SIZEOF_PROGRAM) &&
-         sim->p2 * 8 <= ((sim->p1 * 8) + SIZEOF_PROGRAM))
-  {
-    sim->p2 = rand() % (SIMULATION_SIZE / SIZEOF_PROGRAM);
-  }
-}
-
-void simulation_update(struct Simulation *sim)
-{
-  sv_t a = SV(sim->buffer + (sim->p1 * SIZEOF_PROGRAM), 64);
-  sv_t b = SV(sim->buffer + (sim->p2 * SIZEOF_PROGRAM), 64);
-
-  struct ProgramConcat prog_concat = {0};
-  program_concat(&prog_concat, a, b);
-  program_execute(&prog_concat);
-  program_split(&prog_concat);
-}
-
 Color simulation_cell_color(const u8 *program)
 {
   // How do we compute a "colour" for a program?  I say we count all the valid
@@ -160,7 +116,6 @@ int main(void)
   SetTargetFPS(60);
   for (size_t ticks = 0; !WindowShouldClose(); ++ticks)
   {
-    simulation_pick(&sim);
     simulation_update(&sim);
     BeginDrawing();
     ClearBackground(BLACK);
diff --git a/src/simulation.c b/src/simulation.c
new file mode 100644
index 0000000..5343b8e
--- /dev/null
+++ b/src/simulation.c
@@ -0,0 +1,53 @@
+/* simulation.c: Simulation implementation
+ * Created: 2026-03-10
+ * Author: Aryadev Chavali
+ * License: See end of file
+ */
+
+#include <stdlib.h>
+
+#include "simulation.h"
+
+void simulation_init(struct Simulation *sim)
+{
+  for (u64 i = 0; i < SIMULATION_SIZE / sizeof(u16); ++i)
+  {
+    ((u16 *)(sim->buffer))[i] = rand() % UINT16_MAX;
+  }
+}
+
+void simulation_pick(struct Simulation *sim)
+{
+  sim->p1 = rand() % (SIMULATION_SIZE / SIZEOF_PROGRAM);
+  sim->p2 = rand() % (SIMULATION_SIZE / SIZEOF_PROGRAM);
+  while (sim->p1 * 8 <= ((sim->p2 * 8) + SIZEOF_PROGRAM) &&
+         sim->p2 * 8 <= ((sim->p1 * 8) + SIZEOF_PROGRAM))
+  {
+    sim->p2 = rand() % (SIMULATION_SIZE / SIZEOF_PROGRAM);
+  }
+}
+
+void simulation_update(struct Simulation *sim)
+{
+  simulation_pick(sim);
+  sv_t a = SV(sim->buffer + (sim->p1 * SIZEOF_PROGRAM), 64);
+  sv_t b = SV(sim->buffer + (sim->p2 * SIZEOF_PROGRAM), 64);
+
+  struct ProgramConcat prog_concat = {0};
+  program_concat(&prog_concat, a, b);
+  program_execute(&prog_concat);
+  program_split(&prog_concat);
+}
+
+/* Copyright (C) 2026 Aryadev Chavali
+
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License Version 2 for
+ * details.
+
+ * You may distribute and modify this code under the terms of the GNU General
+ * Public License Version 2, which you should have received a copy of along with
+ * this program.  If not, please go to <https://www.gnu.org/licenses/>.
+
+ */
diff --git a/src/simulation.h b/src/simulation.h
new file mode 100644
index 0000000..89d7da7
--- /dev/null
+++ b/src/simulation.h
@@ -0,0 +1,41 @@
+/* simulation.h: Simulation handlers and helpers
+ * Created: 2026-03-10
+ * Author: Aryadev Chavali
+ * License: See end of file
+ * Commentary:
+ */
+
+#ifndef SIMULATION_H
+#define SIMULATION_H
+
+#include "program_iter.h"
+
+#define NUM_PROGRAMS_POW_2 10
+#define NUM_PROGRAMS       (1LU << NUM_PROGRAMS_POW_2)
+#define SIMULATION_SIZE    (SIZEOF_PROGRAM * NUM_PROGRAMS)
+
+// Simulation is simply a massive tape.  We pick two 64 byte portions of this
+// buffer for our update procedure, which is based on program_iter.
+struct Simulation
+{
+  char buffer[SIMULATION_SIZE];
+  u64 p1, p2;
+};
+
+void simulation_init(struct Simulation *sim);
+void simulation_update(struct Simulation *sim);
+
+#endif
+
+/* Copyright (C) 2026 Aryadev Chavali
+
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License Version 2 for
+ * details.
+
+ * You may distribute and modify this code under the terms of the GNU General
+ * Public License Version 2, which you should have received a copy of along with
+ * this program.  If not, please go to <https://www.gnu.org/licenses/>.
+
+ */