diff --git a/README.md b/README.md
index 7842555..88971a0 100644
--- a/README.md
+++ b/README.md
@@ -352,7 +352,7 @@ the resource constraints, the following limitations apply:
   program in the VM),
 * the program itself is entered into the DATA statements in the so-called
   MU74 format (see below),
-* no support for I/O port 2, tracing or intruction dumping,
+* no support for tracing or intruction dumping (I/O ports 1-2 supported though),
 * no boundary checks for the addresses inside the program.
 
 Also, since the VM runs on top of a BASIC interpreter, program execution is
diff --git a/mu808.b74 b/mu808.b74
index a64e35f..5e3db74 100644
--- a/mu808.b74
+++ b/mu808.b74
@@ -39,7 +39,7 @@
 480 NEXT I:GOTO 180
 490 IF CMD=4 THEN 500 ELSE 530
 500 FOR I=X TO Y
-510 IF Z=0 THEN INPUT DMEM(I)
+510 IF Z=0 THEN INPUT DMEM(I) ELSE IF Z=2 THEN DMEM(I)=ASC(KEY$)
 520 NEXT I:GOTO 180
 530 IF CMD=6 THEN 540 ELSE 570
 540 IF X=0 THEN DMEM(Z)=Y:GOTO 180