diff --git a/toolbox/mm.cpp b/toolbox/mm.cpp
index f72d089..58ec8aa 100644
--- a/toolbox/mm.cpp
+++ b/toolbox/mm.cpp
@@ -294,6 +294,29 @@ namespace MM
 		return mplite_maxmem(&pool);
 	}
 
+	uint32_t MaxBlock(uint16_t trap)
+	{
+		/*
+		 * The MaxBlock function returns the maximum contiguous space, in bytes, that you 
+		 * could obtain after compacting the current heap zone. MaxBlock does not actually 
+		 * do the compaction.
+		 */
+		 
+		/* 
+		 * on entry:
+		 * (nothing)
+		 *
+		 * on exit:
+		 * D0: function result (long word)
+		 *
+		 */
+
+		Log("%04x MaxBlock()\n", trap);
+
+		SetMemError(0);
+		return mplite_maxmem(&pool);
+	}
+
 	uint32_t FreeMem(uint16_t trap)
 	{
 		// total free memory.
@@ -312,6 +335,9 @@ namespace MM
 		return mplite_freemem(&pool);
 	}
 
+
+
+
 	uint16_t ReserveMem(uint16_t trap)
 	{
 		/* 
diff --git a/toolbox/mm.h b/toolbox/mm.h
index 478c354..2cf7457 100644
--- a/toolbox/mm.h
+++ b/toolbox/mm.h
@@ -27,6 +27,7 @@ namespace MM
 	uint16_t BlockMove(uint16_t trap);
 	uint32_t CompactMem(uint16_t trap);
 	uint32_t MaxMem(uint16_t trap);
+	uint32_t MaxBlock(uint16_t trap);
 	uint32_t FreeMem(uint16_t trap);
 	uint16_t ReserveMem(uint16_t trap);
 	
diff --git a/toolbox/toolbox.cpp b/toolbox/toolbox.cpp
index 904fbb0..b689ff6 100644
--- a/toolbox/toolbox.cpp
+++ b/toolbox/toolbox.cpp
@@ -159,6 +159,10 @@ namespace ToolBox {
 				d0 = MM::StripAddress(trap);
 				break;
 
+			case 0xa061:
+				d0 = MM::MaxBlock(trap);
+				break;
+
 			// MoveHHi (h: Handle);
 			case 0xa064:
 				d0 = MM::MoveHHi(trap);