diff --git a/plugins/cheat/cheat_xml.lua b/plugins/cheat/cheat_xml.lua
index ac63bb76c7c..cb849fe0b07 100644
--- a/plugins/cheat/cheat_xml.lua
+++ b/plugins/cheat/cheat_xml.lua
@@ -54,27 +54,46 @@ local function xml_parse(data)
 	return xml_table
 end
 
+local cpu_spaces = {}
+
+for tag, device in pairs(manager:machine().devices) do
+	local sp
+	for name, space in pairs(device.spaces) do
+		if not sp then
+			sp = {}
+			cpu_spaces[tag] = sp
+		end
+		sp[space.index] = space.name
+	end
+end
+
 function xml.conv_cheat(data)
 	local spaces, regions, output
 	data = xml_parse(data)
+
 	local function convert_expr(data)
 		local write = false
 
 		local function convert_memref(cpu, phys, space, width, addr, rw)
+			-- debug expressions address spaces by index not by name
+			local function get_space_name(index)
+				return cpu_spaces[":" .. cpu][index]
+			end
+
 			local mod = ""
 			local count
 			if space == "p" then
-				fullspace = "program"
+				fullspace = get_space_name(0)
 			elseif space == "d" then
-				fullspace = "data"
+				fullspace = get_space_name(1)
 			elseif space == "i" then
-				fullspace = "io"
+				fullspace = get_space_name(2)
 			elseif space == "r" then
-				fullspace = "program"
+				fullspace = get_space_name(0)
 				mod = "direct_"
 				space = "p"
 			elseif space == "o" then
-				fullspace = "decrypted_opcodes"
+				fullspace = get_space_name(3)
 				mod = "direct_"
 				space = "o"
 			end
diff --git a/src/frontend/mame/luaengine.cpp b/src/frontend/mame/luaengine.cpp
index e8e45bbf2fd..846d24dbbd0 100644
--- a/src/frontend/mame/luaengine.cpp
+++ b/src/frontend/mame/luaengine.cpp
@@ -1441,8 +1441,9 @@ void lua_engine::initialize()
 			"write_direct_u32", &addr_space::direct_mem_write<uint32_t>,
 			"write_direct_i64", &addr_space::direct_mem_write<int64_t>,
 			"write_direct_u64", &addr_space::direct_mem_write<uint64_t>,
-			"name", sol::property(&addr_space::name),
+			"name", sol::property([](addr_space &sp) { return sp.space.name(); }),
 			"shift", sol::property([](addr_space &sp) { return sp.space.addr_shift(); }),
+			"index", sol::property([](addr_space &sp) { return sp.space.spacenum(); }),
 			"map", sol::property([this](addr_space &sp) {
 					address_space &space = sp.space;
 					sol::table map = sol().create_table();
diff --git a/src/frontend/mame/luaengine.h b/src/frontend/mame/luaengine.h
index d346abe2857..205c84f2e36 100644
--- a/src/frontend/mame/luaengine.h
+++ b/src/frontend/mame/luaengine.h
@@ -138,7 +138,6 @@ private:
 		template<typename T> void log_mem_write(offs_t address, T val);
 		template<typename T> T direct_mem_read(offs_t address);
 		template<typename T> void direct_mem_write(offs_t address, T val);
-		const char *name() const { return space.name(); }
 
 		address_space &space;
 		device_memory_interface &dev;
diff --git a/src/mame/drivers/pc9801.cpp b/src/mame/drivers/pc9801.cpp
index 55076ea8d7e..b52c78d5689 100644
--- a/src/mame/drivers/pc9801.cpp
+++ b/src/mame/drivers/pc9801.cpp
@@ -2333,12 +2333,12 @@ MACHINE_CONFIG_START(pc9801_state::pc9801_common)
 	MCFG_SCREEN_UPDATE_DRIVER(pc9801_state, screen_update)
 	MCFG_SCREEN_VBLANK_CALLBACK(WRITELINE(pc9801_state, vrtc_irq))
 
-	MCFG_DEVICE_ADD("upd7220_chr", UPD7220, 5000000/2)
+	MCFG_DEVICE_ADD("upd7220_chr", UPD7220, 21.0526_MHz_XTAL / 8)
 	MCFG_DEVICE_ADDRESS_MAP(0, upd7220_1_map)
 	MCFG_UPD7220_DRAW_TEXT_CALLBACK_OWNER(pc9801_state, hgdc_draw_text)
 	MCFG_UPD7220_VSYNC_CALLBACK(DEVWRITELINE("upd7220_btm", upd7220_device, ext_sync_w))
 
-	MCFG_DEVICE_ADD("upd7220_btm", UPD7220, 5000000/2)
+	MCFG_DEVICE_ADD("upd7220_btm", UPD7220, 21.0526_MHz_XTAL / 8)
 	MCFG_DEVICE_ADDRESS_MAP(0, upd7220_2_map)
 	MCFG_UPD7220_DISPLAY_PIXELS_CALLBACK_OWNER(pc9801_state, hgdc_display_pixels)