diff --git a/Source/HBIOS/sio.asm b/Source/HBIOS/sio.asm
index 2a101d48..4f7f9b86 100644
--- a/Source/HBIOS/sio.asm
+++ b/Source/HBIOS/sio.asm
@@ -69,8 +69,8 @@ SIO0B_DAT	.EQU	SIO0BASE + $05
 ;
 #IF (SIO0MODE == SIOMODE_Z80R)
 SIO0A_CMD	.EQU	SIO0BASE + $03
-SIO0A_DAT	.EQU	SIO0BASE + $02 
-SIO0B_CMD	.EQU	SIO0BASE + $01
+SIO0A_DAT	.EQU	SIO0BASE + $01
+SIO0B_CMD	.EQU	SIO0BASE + $02
 SIO0B_DAT	.EQU	SIO0BASE + $00
 #ENDIF
 ;
@@ -106,8 +106,8 @@ SIO1B_DAT	.EQU	SIO1BASE + $05
 ;
 #IF (SIO1MODE == SIOMODE_Z80R)
 SIO1A_CMD	.EQU	SIO0BASE + $03
-SIO1A_DAT	.EQU	SIO0BASE + $02 
-SIO1B_CMD	.EQU	SIO0BASE + $01
+SIO1A_DAT	.EQU	SIO0BASE + $01 
+SIO1B_CMD	.EQU	SIO0BASE + $02
 SIO1B_DAT	.EQU	SIO0BASE + $00
 #ENDIF
 ;
diff --git a/Source/ver.inc b/Source/ver.inc
index 89186f9b..170823eb 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,7 +2,7 @@
 #DEFINE	RMN	3
 #DEFINE	RUP	0
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.3.0-dev.1"
+#DEFINE BIOSVER	"3.3.0-dev.2"
 #define rmj	RMJ
 #define rmn	RMN
 #define rup	RUP
diff --git a/Source/ver.lib b/Source/ver.lib
index 1d3826c0..9d8d6895 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	3
 rup	equ	0
 rtp	equ	0
 biosver	macro
-	db	"3.3.0-dev.1"
+	db	"3.3.0-dev.2"
 	endm