diff --git a/Makefile b/Makefile
index bb079c6..6ba68e5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,3 +1,5 @@
+DOSBOX=dosbox -conf dosbox.conf -exit
+
 ordos.img: BOOT.BIN IO.SYS ORDOS.SYS COMMAND.COM debug.com edlin.com exe2bin.exe link.exe masm.exe
 	rm -f ordos.img
 	mkfs.fat -C $@ -M 0xff 320
@@ -12,16 +14,16 @@ ordos.img: BOOT.BIN IO.SYS ORDOS.SYS COMMAND.COM debug.com edlin.com exe2bin.exe
 	mcopy -i $@ masm.exe ::
 
 BOOT.BIN: boot.asm
-	dosbox -exit mk-boot.bat
+	$(DOSBOX) mk-boot.bat
 
 IO.SYS: io.asm
-	dosbox -exit mk-io.bat
+	$(DOSBOX) mk-io.bat
 
 ORDOS.SYS: msdos.asm stddos.asm
-	dosbox -exit mk-ordos.bat
+	$(DOSBOX) mk-ordos.bat
 
 COMMAND.COM: command.asm
-	dosbox -exit mk-comma.bat
+	$(DOSBOX) mk-comma.bat
 
 clean:
 	rm -f ordos.img *.OBJ *.EXE *.COM *.BIN *.SYS
diff --git a/dosbox.conf b/dosbox.conf
new file mode 100644
index 0000000..bdaaa83
--- /dev/null
+++ b/dosbox.conf
@@ -0,0 +1,2 @@
+[cpu]
+cycles=max