diff --git a/Source/HBIOS/cfg_duo.asm b/Source/HBIOS/cfg_duo.asm
index 5d360c09..ed38af39 100644
--- a/Source/HBIOS/cfg_duo.asm
+++ b/Source/HBIOS/cfg_duo.asm
@@ -88,6 +88,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_dyno.asm b/Source/HBIOS/cfg_dyno.asm
index 56cfffa5..ea3220ff 100644
--- a/Source/HBIOS/cfg_dyno.asm
+++ b/Source/HBIOS/cfg_dyno.asm
@@ -90,6 +90,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_heath.asm b/Source/HBIOS/cfg_heath.asm
index 77335229..d9fcf6a4 100644
--- a/Source/HBIOS/cfg_heath.asm
+++ b/Source/HBIOS/cfg_heath.asm
@@ -90,6 +90,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_master.asm b/Source/HBIOS/cfg_master.asm
index 1f8c70fa..d048d332 100644
--- a/Source/HBIOS/cfg_master.asm
+++ b/Source/HBIOS/cfg_master.asm
@@ -119,6 +119,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_mbc.asm b/Source/HBIOS/cfg_mbc.asm
index b67b1d39..49ffc623 100644
--- a/Source/HBIOS/cfg_mbc.asm
+++ b/Source/HBIOS/cfg_mbc.asm
@@ -85,6 +85,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_mk4.asm b/Source/HBIOS/cfg_mk4.asm
index 0e174fcb..6a4afca6 100644
--- a/Source/HBIOS/cfg_mk4.asm
+++ b/Source/HBIOS/cfg_mk4.asm
@@ -90,6 +90,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_n8.asm b/Source/HBIOS/cfg_n8.asm
index 80d3e1a0..1038df1a 100644
--- a/Source/HBIOS/cfg_n8.asm
+++ b/Source/HBIOS/cfg_n8.asm
@@ -92,6 +92,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_rcz180.asm b/Source/HBIOS/cfg_rcz180.asm
index bfcb305b..02efb3e4 100644
--- a/Source/HBIOS/cfg_rcz180.asm
+++ b/Source/HBIOS/cfg_rcz180.asm
@@ -96,6 +96,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_rcz280.asm b/Source/HBIOS/cfg_rcz280.asm
index 5e1399e1..dcdf08e5 100644
--- a/Source/HBIOS/cfg_rcz280.asm
+++ b/Source/HBIOS/cfg_rcz280.asm
@@ -90,6 +90,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_rcz80.asm b/Source/HBIOS/cfg_rcz80.asm
index dac63190..f9f84ac4 100644
--- a/Source/HBIOS/cfg_rcz80.asm
+++ b/Source/HBIOS/cfg_rcz80.asm
@@ -90,6 +90,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_rph.asm b/Source/HBIOS/cfg_rph.asm
index bae33dd2..017e41db 100644
--- a/Source/HBIOS/cfg_rph.asm
+++ b/Source/HBIOS/cfg_rph.asm
@@ -90,6 +90,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_s100.asm b/Source/HBIOS/cfg_s100.asm
index 7e999a30..94b77fc7 100644
--- a/Source/HBIOS/cfg_s100.asm
+++ b/Source/HBIOS/cfg_s100.asm
@@ -90,6 +90,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_sbc.asm b/Source/HBIOS/cfg_sbc.asm
index 23185ce6..c9ba3f64 100644
--- a/Source/HBIOS/cfg_sbc.asm
+++ b/Source/HBIOS/cfg_sbc.asm
@@ -85,6 +85,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_scz180.asm b/Source/HBIOS/cfg_scz180.asm
index faab26af..ae61ef55 100644
--- a/Source/HBIOS/cfg_scz180.asm
+++ b/Source/HBIOS/cfg_scz180.asm
@@ -90,6 +90,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_z80retro.asm b/Source/HBIOS/cfg_z80retro.asm
index d7264eef..2432a2ad 100644
--- a/Source/HBIOS/cfg_z80retro.asm
+++ b/Source/HBIOS/cfg_z80retro.asm
@@ -88,6 +88,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_zeta.asm b/Source/HBIOS/cfg_zeta.asm
index 4fee5070..2065bac7 100644
--- a/Source/HBIOS/cfg_zeta.asm
+++ b/Source/HBIOS/cfg_zeta.asm
@@ -77,6 +77,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD
diff --git a/Source/HBIOS/cfg_zeta2.asm b/Source/HBIOS/cfg_zeta2.asm
index 00eebcde..22dfb7c8 100644
--- a/Source/HBIOS/cfg_zeta2.asm
+++ b/Source/HBIOS/cfg_zeta2.asm
@@ -88,6 +88,7 @@ PKDOSC		.EQU	3000000		; OSCILLATOR FREQ FOR PKD (IN HZ)
 H8PENABLE	.EQU	FALSE		; ENABLES HEATH H8 FRONT PANEL
 ;
 BOOTCON		.EQU	0		; BOOT CONSOLE DEVICE
+SECCON		.EQU	$FF		; SECONDARY CONSOLE DEVICE
 CRTACT		.EQU	FALSE		; ACTIVATE CRT (VDU,CVDU,PROPIO,ETC) AT STARTUP
 VDAEMU		.EQU	EMUTYP_ANSI	; VDA EMULATION: EMUTYP_[TTY|ANSI]
 VDAEMU_SERKBD	.EQU	$FF		; VDA EMULATION: SERIAL KBD UNIT #, OR $FF FOR HW KBD