diff --git a/Makefile b/Makefile
index dc9ff32..e9b37a9 100644
--- a/Makefile
+++ b/Makefile
@@ -14,6 +14,7 @@ SRC = \
 	  src/printf.c          \
 	  src/lfsr.c            \
 	  src/matrix.c          \
+	  src/mmap.c            \
 	  src/flipflap.c        \
 	  \
 
diff --git a/src/main.c b/src/main.c
index 890f7e8..844d9a7 100644
--- a/src/main.c
+++ b/src/main.c
@@ -6,6 +6,7 @@
 #include "io.h"
 #include "lfsr.h"
 #include "matrix.h"
+#include "mmap.h"
 #include "printf.h"
 #include "video.h"
 
@@ -44,7 +45,7 @@ const uint8_t FVB[15 * 8] = {
 };
 
 int main(void) {
-    io_out(0x81, io_in(0x81) & ~0x01);
+    mmap_set(MMAP_MODE_CEDA_VIDEO);
 
     for (;;) {
         cursor_enable(false);
@@ -96,7 +97,4 @@ int main(void) {
 
         crt_waitFrames(250);
     }
-
-    io_out(0x81, io_in(0x81) | 0x01);
-    return 0;
 }
diff --git a/src/video.c b/src/video.c
index f5e893c..83b910d 100644
--- a/src/video.c
+++ b/src/video.c
@@ -1,6 +1,7 @@
 #include "video.h"
 
 #include "io.h"
+#include "mmap.h"
 
 #include <stdint.h>
 
@@ -29,9 +30,9 @@ void video_putchar(char c) {
     }
 
     if (hstretch) {
-        io_out(0x81, io_in(0x81) | 0x80);
+        mmap_set(MMAP_MODE_CEDA_ATTR);
         *(VIDEO_MEMORY + offset) |= 0x08;
-        io_out(0x81, io_in(0x81) & ~0x80);
+        mmap_set(MMAP_MODE_CEDA_VIDEO);
     }
 
     if (c == '\t') {
@@ -44,12 +45,12 @@ void video_putchar(char c) {
     if (vstretch) {
         *(VIDEO_MEMORY + offset + 80) = c;
 
-        io_out(0x81, io_in(0x81) | 0x80);
+        mmap_set(MMAP_MODE_CEDA_ATTR);
         *(VIDEO_MEMORY + offset) |= 0x60;
         *(VIDEO_MEMORY + offset + 80) |= 0x70;
         if (hstretch)
             *(VIDEO_MEMORY + offset + 80) |= 0x08;
-        io_out(0x81, io_in(0x81) & ~0x80);
+        mmap_set(MMAP_MODE_CEDA_VIDEO);
     }
 
     ++offset;