diff --git a/Source/HBIOS/nabu.asm b/Source/HBIOS/nabu.asm
index 817c6ef3..6862337a 100644
--- a/Source/HBIOS/nabu.asm
+++ b/Source/HBIOS/nabu.asm
@@ -50,13 +50,13 @@ NABU_PREINIT:
 	; PORT B IN READ MODE
 ;
 	; SET I/O PORT MODES
-	LD	A,7			; PSG REGISTER 7 (ENABLE REG)
+	LD	A,7			; PSG R7 (ENABLE REG)
 	OUT	(NABU_RSEL),A		; SELECT IT
 	LD	A,%01000000		; PORT B INPUT, PORT A OUPUT
 	OUT	(NABU_RDAT),A		; SET IT
 ;
 	; SET PORT A TO VALUE 0
-	LD	A,16			; PSG REGISTER 16 (PORT A DATA)
+	LD	A,14			; PSG R16 (PORT A DATA)
 	OUT	(NABU_RSEL),A		; SELECT IT
 	XOR	A			; VALUE 0
 	OUT	(NABU_RDAT),A		; SET IT