1 files changed, 10 insertions, 0 deletions
diff --git a/src/isa.adb b/src/isa.adb
new file mode 100644
index 0000000..5941660
--- /dev/null
+++ b/src/isa.adb
@@ -0,0 +1,10 @@
+package body ISA is
+   function To_Byte (O : Opcode) return Byte
+      is (Byte (O.Value mod 256));
+
+   function X_Register (O : Opcode) return Register_Index
+      is (Register_Index (O.Value / 256));
+
+   function Y_Register (O : Opcode) return Register_Index
+      is (Register_Index (O.Value / 16 mod 16));
+end ISA;