diff --git a/test/occupation.nas b/test/occupation.nas
index 348bbc3..dd62575 100644
--- a/test/occupation.nas
+++ b/test/occupation.nas
@@ -37,11 +37,11 @@ var cpu_occupation = func() {
     while(1) {
         var cpu0 = cpu_stat();
         if (first_in) {
-            unix.sleep(0.1);
+            unix.sleep(0.05);
             first_in = 0;
         } else {
             for(var i = 0; i < 10; i += 1) {
-                unix.sleep(0.1);
+                unix.sleep(0.05);
                 coroutine.yield(nil);
             }
         }
diff --git a/test/tui.nas b/test/tui.nas
new file mode 100644
index 0000000..ec342ba
--- /dev/null
+++ b/test/tui.nas
@@ -0,0 +1,53 @@
+use std.utils;
+use std.unix;
+
+var screen_state = {
+    width: 0,
+    height: 0
+};
+
+screen_state.update = func() {
+    var res = utils.terminal_size();
+    me.width = res.cols;
+    me.height = res.rows;
+}
+
+screen_state.clear_screen = func() {
+    me.update();
+
+    var screen = "\e[0;0H";
+    for (var i = 0; i < me.height; i+=1) {
+        for (var j = 0; j < me.width; j+=1) {
+            screen ~= " ";
+        }
+        if (i != me.height - 1)
+            screen ~= "\n";
+    }
+    print(screen, "\e[0;0H");
+}
+
+screen_state.put_pixel = func(x, y, c) {
+    x = int(x);
+    y = int(y);
+    if (x < 0 or x >= me.width or y < 0 or y >= me.height)
+        return;
+    var coord = "\e[" ~ y ~ ";" ~ x ~ "H";
+    print(coord, c, "\e[0;0H");
+}
+
+var test_flush = func() {
+    screen_state.clear_screen();
+    for(var i=0; i<1e6; i+=1) {
+        unix.sleep(0.001);
+        screen_state.update();
+        screen_state.put_pixel(
+            rand()*screen_state.width,
+            rand()*screen_state.height,
+            "\e[38;5;" ~ int(256*rand()) ~ "m" ~ char(65 + 26*rand()) ~ "\e[0m"
+        );
+        print("\e[0;0H", i);
+    }
+
+    screen_state.clear_screen();
+    println();
+}
\ No newline at end of file