diff --git a/src/cpu.ml b/src/cpu.ml
new file mode 100644
index 0000000..61e7af5
--- /dev/null
+++ b/src/cpu.ml
@@ -0,0 +1,26 @@
+(** http://bgb.bircd.org/pandocs.htm#cpuregistersandflags *)
+
+type registers = {
+  a : char;
+  b : char;
+  c : char;
+  d : char;
+  e : char;
+  h : char;
+  l : char;
+
+  sp : int;
+  pc : int;
+}
+
+type flags = {
+  zf : bool;
+  n  : bool;
+  h  : bool;
+  cy : bool;
+}
+
+type t = {
+  reg : registers;
+  flags : flags;
+}