diff --git a/gui/m291/src/m291.tal b/gui/m291/src/m291.tal
index d06644a..e112d9e 100644
--- a/gui/m291/src/m291.tal
+++ b/gui/m291/src/m291.tal
@@ -369,6 +369,8 @@
 	&folder ( line* -- )
 	DUP2 llen #003f LTH2 ?{ POP2 JMP2r }
 	;mem/folders [ LIT2 00 -lines/folders ] LDZ
+	( | max folders = 3000 / 80 = 60 )
+	DUP #60 LTH ?{ POP POP2 JMP2r }
 	( CELLSIZE ) #70 SFT2 ADD2 <lcpy>
 	.lines/folders LDZ INC .lines/folders STZ
 	JMP2r
@@ -377,6 +379,8 @@
 	DUP2 llen
 	( CELLSIZE ) #007f LTH2 ?{ POP2 JMP2r }
 	;mem/tracks [ LIT2 00 -lines/tracks ] LDZ
+	( | max tracks = 80 )
+	DUP #80 LTH ?{ POP JMP2r }
 	( CELLSIZE ) #70 SFT2 ADD2 <lcpy>
 	.lines/tracks LDZ INC .lines/tracks STZ
 	JMP2r