diff --git a/jvs/jvs-cmd.h b/jvs/jvs-cmd.h
new file mode 100644
index 0000000..0197c9f
--- /dev/null
+++ b/jvs/jvs-cmd.h
@@ -0,0 +1,45 @@
+#pragma once
+
+enum {
+    JVS_CMD_READ_ID = 0x10,
+    JVS_CMD_GET_CMD_VERSION = 0x11,
+    JVS_CMD_GET_JVS_VERSION = 0x12,
+    JVS_CMD_GET_COMM_VERSION = 0x13,
+    JVS_CMD_GET_FEATURES = 0x14,
+    JVS_CMD_READ_SWITCHES = 0x20,
+    JVS_CMD_READ_COIN = 0x21,
+    JVS_CMD_READ_ANALOGS = 0x22,
+    JVS_CMD_WRITE_GPIO = 0x32,
+    JVS_CMD_RESET = 0xF0,
+    JVS_CMD_ASSIGN_ADDR = 0xF1,
+};
+
+#pragma pack(push, 1)
+
+struct jvs_req_read_switches {
+    uint8_t cmd;
+    uint8_t num_players;
+    uint8_t bytes_per_player;
+};
+
+struct jvs_req_read_coin {
+    uint8_t cmd;
+    uint8_t nslots;
+};
+
+struct jvs_req_read_analogs {
+    uint8_t cmd;
+    uint8_t nanalogs;
+};
+
+struct jvs_req_reset {
+    uint8_t cmd;
+    uint8_t unknown;
+};
+
+struct jvs_req_assign_addr {
+    uint8_t cmd;
+    uint8_t addr;
+};
+
+#pragma pack(pop)
diff --git a/jvs/meson.build b/jvs/meson.build
index 3c90966..49737a0 100644
--- a/jvs/meson.build
+++ b/jvs/meson.build
@@ -9,6 +9,7 @@ jvs_lib = static_library(
     sources : [
         'jvs-bus.c',
         'jvs-bus.h',
+        'jvs-cmd.h',
         'jvs-frame.c',
         'jvs-frame.h',
         'jvs-util.c',