diff --git a/Source/HBIOS/cfg_DUO.asm b/Source/HBIOS/cfg_DUO.asm
index 8bc8769e..9f673e01 100644
--- a/Source/HBIOS/cfg_DUO.asm
+++ b/Source/HBIOS/cfg_DUO.asm
@@ -375,6 +375,9 @@ AYMODE		.SET	AYMODE_DUO	; AY: DRIVER MODE: AYMODE_[SCG|N8|RCZ80|RCZ180|MSX|LINC|
 AY_FORCE	.SET	FALSE		; AY: BYPASS AUTO-DETECT, FORCED PRESENT
 ;
 SPKENABLE	.SET	TRUE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
+SPKPORT		.SET	RTCIO		; SPK: THE PORT WITH THE SPEAKER IO BIT
+SPKSHADOW	.SET	HB_RTCVAL	; SPK: THE SHADOW VALUE FOR THE PORT THAT HAS TO BE MAINTAINED
+SPKMASK		.SET	%00000100	; SPK: THE BIT MASK TO ACTUALLY TOGGLE
 ;
 DMAENABLE	.SET	FALSE		; DMA: ENABLE DMA DRIVER (DMA.ASM)
 DMABASE		.SET	$40		; DMA: DMA BASE ADDRESS
diff --git a/Source/HBIOS/cfg_MASTER.asm b/Source/HBIOS/cfg_MASTER.asm
index fd8ff97d..bb6a4b58 100644
--- a/Source/HBIOS/cfg_MASTER.asm
+++ b/Source/HBIOS/cfg_MASTER.asm
@@ -465,7 +465,7 @@ AY_FORCE	.EQU	FALSE		; AY: BYPASS AUTO-DETECT, FORCED PRESENT
 SPKENABLE	.EQU	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
 SPKPORT		.EQU	RTCIO		; SPK: THE PORT WITH THE SPEAKER IO BIT
 SPKSHADOW	.EQU	HB_RTCVAL	; SPK: THE SHADOW VALUE FOR THE PORT THAT HAS TO BE MAINTAINED
-SPKMASK		.EQU	00000100b	; SPK: THE BIT MASK TO ACTUALLY TOGGLE
+SPKMASK		.EQU	%00000100	; SPK: THE BIT MASK TO ACTUALLY TOGGLE
 ;
 DMAENABLE	.EQU	FALSE		; DMA: ENABLE DMA DRIVER (DMA.ASM)
 DMABASE		.EQU	$E0		; DMA: DMA BASE ADDRESS
diff --git a/Source/HBIOS/cfg_MBC.asm b/Source/HBIOS/cfg_MBC.asm
index e1ad3e1f..a137c5d0 100644
--- a/Source/HBIOS/cfg_MBC.asm
+++ b/Source/HBIOS/cfg_MBC.asm
@@ -362,6 +362,9 @@ AY_CLK		.SET	1789772		; AY: PSG CLOCK FREQ, ASSUME MSX STD
 AYMODE		.SET	AYMODE_MBC	; AY: DRIVER MODE: AYMODE_[SCG|N8|RCZ80|RCZ180|MSX|LINC|MBC|DUO|NABU]
 ;
 SPKENABLE	.SET	TRUE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
+SPKPORT		.SET	RTCIO		; SPK: THE PORT WITH THE SPEAKER IO BIT
+SPKSHADOW	.SET	HB_RTCVAL	; SPK: THE SHADOW VALUE FOR THE PORT THAT HAS TO BE MAINTAINED
+SPKMASK		.SET	%00000100	; SPK: THE BIT MASK TO ACTUALLY TOGGLE
 ;
 DMAENABLE	.SET	FALSE		; DMA: ENABLE DMA DRIVER (DMA.ASM)
 DMABASE		.SET	$E0		; DMA: DMA BASE ADDRESS
diff --git a/Source/HBIOS/cfg_SBC.asm b/Source/HBIOS/cfg_SBC.asm
index f0a2b488..4b13996f 100644
--- a/Source/HBIOS/cfg_SBC.asm
+++ b/Source/HBIOS/cfg_SBC.asm
@@ -348,6 +348,9 @@ AYMODE		.SET	AYMODE_SCG	; AY: DRIVER MODE: AYMODE_[SCG|N8|RCZ80|RCZ180|MSX|LINC|
 AY_FORCE	.SET	FALSE		; AY: BYPASS AUTO-DETECT, FORCED PRESENT
 ;
 SPKENABLE	.SET	FALSE		; SPK: ENABLE RTC LATCH IOBIT SOUND DRIVER (SPK.ASM)
+SPKPORT		.SET	RTCIO		; SPK: THE PORT WITH THE SPEAKER IO BIT
+SPKSHADOW	.SET	HB_RTCVAL	; SPK: THE SHADOW VALUE FOR THE PORT THAT HAS TO BE MAINTAINED
+SPKMASK		.SET	%00000100	; SPK: THE BIT MASK TO ACTUALLY TOGGLE
 ;
 DMAENABLE	.SET	FALSE		; DMA: ENABLE DMA DRIVER (DMA.ASM)
 DMABASE		.SET	$E0		; DMA: DMA BASE ADDRESS