diff --git a/src/Core.Terminal/ControlBuilderExtensions.cs b/src/Core.Terminal/ControlBuilderExtensions.cs
new file mode 100644
index 0000000..9c50978
--- /dev/null
+++ b/src/Core.Terminal/ControlBuilderExtensions.cs
@@ -0,0 +1,85 @@
+using System.Text;
+using Vezel.Cathode.Text.Control;
+using static Vezel.Cathode.Text.Control.ControlConstants;
+
+namespace OkTools.Core.Terminal;
+
+public readonly struct AutoSaveRestoreCursorState : IDisposable
+{
+    readonly ControlBuilder _cb;
+
+    public AutoSaveRestoreCursorState(ControlBuilder cb) =>
+        (_cb = cb).SaveCursorState();
+    public void Dispose() =>
+        _cb.RestoreCursorState();
+}
+
+public enum CursorConstrainMode
+{
+    // [Default] Origin is upper-left of screen. Cursor positioning will ignore any configured margin, though some
+    // operations such as MoveCursorTo() will constrain to the margin, if configured.
+    Screen,
+
+    // Origin is upper-left of margin. All cursor operations will be constrained to the current margin.
+    Margin
+}
+
+[PublicAPI]
+public static class ControlBuilderExtensions
+{
+    // for a good time, go to https://vt100.net/docs/vt100-ug/chapter3.html
+
+    public static ControlBuilder Print(this ControlBuilder @this, StringBuilder sb)
+    {
+        foreach (var chunk in sb.GetChunks())
+            @this.Print(chunk);
+        return @this;
+    }
+
+    public static ControlBuilder Print(this ControlBuilder @this, ReadOnlyMemory<char> mem) =>
+        @this.Print(mem.Span);
+
+    // these are affected by current CursorOrigin
+    public static ControlBuilder MoveCursorHome(this ControlBuilder @this) =>
+        @this.Print(CSI).Print('H');
+    public static ControlBuilder MoveCursorEnd(this ControlBuilder @this) =>
+        @this.MoveCursorTo(10000, 10000);
+
+    public static void MoveCursorHomeLine(this ControlBuilder @this) =>
+        @this.CarriageReturn();
+    public static void MoveCursorEndLine(this ControlBuilder @this) =>
+        @this.MoveCursorRight(10000);
+
+    public static ControlBuilder MoveCursorUp(this ControlBuilder @this) =>
+        @this.MoveCursorUp(1);
+    public static ControlBuilder MoveCursorDown(this ControlBuilder @this) =>
+        @this.MoveCursorDown(1);
+    public static ControlBuilder MoveCursorLeft(this ControlBuilder @this) =>
+        @this.MoveCursorLeft(1);
+    public static ControlBuilder MoveCursorRight(this ControlBuilder @this) =>
+        @this.MoveCursorRight(1);
+
+    public static ControlBuilder MoveBufferUp(this ControlBuilder @this) =>
+        @this.MoveBufferUp(1);
+    public static ControlBuilder MoveBufferDown(this ControlBuilder @this) =>
+        @this.MoveBufferDown(1);
+
+    public static ControlBuilder ResetScrollMargin(this ControlBuilder @this) =>
+        @this.Print(CSI).Print(";r");
+    public static ControlBuilder ReverseLineFeed(this ControlBuilder @this) =>
+        @this.Print(ESC).Print(['M']); // this is reverse index (M), not reverse line feed (H), but this is supported much better and does the same thing according to docs
+
+    public static AutoSaveRestoreCursorState AutoSaveRestoreCursorState(this ControlBuilder @this) =>
+        new(@this);
+
+    // note that this will cause the cursor to move to home position. can't save/restore cursor pos because it is tied
+    // to cursor state, and restoring state will kill the new constrain mode.
+    public static ControlBuilder SetCursorConstrainMode(this ControlBuilder @this, CursorConstrainMode mode) => @this
+        .Print(CSI)
+        .Print(mode switch
+        {
+            CursorConstrainMode.Screen => "?6l",
+            CursorConstrainMode.Margin => "?6h",
+            _ => throw new InvalidOperationException("Illegal flag: " + mode)
+        });
+}
diff --git a/src/Core/SmallExtensions.cs b/src/Core/SmallExtensions.cs
index b289ada..872bfbf 100644
--- a/src/Core/SmallExtensions.cs
+++ b/src/Core/SmallExtensions.cs
@@ -12,6 +12,17 @@ public static class ObjectExtensions
     public static bool IsNot <T>(this object @this) where T: class => @this is not T;
 }
 
+[PublicAPI]
+public static class IntExtensions
+{
+    public static int ClampMin(this int @this, int min) =>
+        @this < min ? min : @this;
+    public static int ClampMax(this int @this, int max) =>
+        @this > max ? max : @this;
+    public static int ClampMaxExcl(this int @this, int max) =>
+        @this >= max ? max-1 : @this;
+}
+
 [PublicAPI]
 public static class RefTypeExtensions
 {