1 files changed, 9 insertions, 5 deletions
diff --git a/sw/z80/tests/pio/main.c b/sw/z80/tests/pio/main.c
index 3687f50..7ac64bc 100644
--- a/sw/z80/tests/pio/main.c
+++ b/sw/z80/tests/pio/main.c
@@ -3,8 +3,8 @@
 #include <stdint.h>
 
 #define PIO_A_DATA  0x10
-#define PIO_A_CMD   0x11
-#define PIO_B_DATA  0x12
+#define PIO_B_DATA  0x11
+#define PIO_A_CMD   0x12
 #define PIO_B_CMD   0x13
 
 void main(void)
@@ -14,21 +14,25 @@ void main(void)
     ld h, #0x00
 
     ;; set bit mode
-    ld a, #0xCF
-    ;; load cmd addr 
     ld c, #PIO_B_CMD
+
+    ld a, #0xCF
     out (c), a
-    ;; set output
+
+    ;; set all pins to output
     ld a, #0x00
     out (c), a
+
     ;; disable interrupts
     ld a, #0x0C
     out (c), a
+
     ;; load data addr
     ld c, #PIO_B_DATA
 loop:
     out (c), h
     ld a, h
+
     cpl
     ld h, a
     jr loop