diff --git a/Source/HBIOS/Build.ps1 b/Source/HBIOS/Build.ps1
index f2f5ee3f..eb60585a 100644
--- a/Source/HBIOS/Build.ps1
+++ b/Source/HBIOS/Build.ps1
@@ -21,13 +21,14 @@ param([string]$Platform = "", [string]$Config = "", [string]$RomSize = "512", [s
 #
 $PlatformListZ80 = "SBC", "ZETA", "ZETA2", "RCZ80", "RCZ280", "EZZ80", "UNA"
 $PlatformListZ180 = "N8", "MK4", "RCZ180", "SCZ180", "DYNO"
+$PlatformListZ280 = "RCZ280"
 
 #
 # Establish the build platform.  It may have been passed in on the command line.  Validate
 # $Platform and loop requesting a new value as long as it is not valid.  The valid platform
 # names are just hard-coded for now.
 #
-$PlatformList = $PlatformListZ80 + $PlatformListZ180
+$PlatformList = $PlatformListZ80 + $PlatformListZ180 + $PlatformListZ280
 $Prompt = "Platform ["
 ForEach ($PlatformName in $PlatformList) {$Prompt += $PlatformName + "|"}
 $Prompt = $Prompt.Substring(0, $Prompt.Length - 1) + "]"
@@ -72,7 +73,9 @@ while ($true)
 # TASM should be invoked with the proper CPU type.  Below, the CPU type is inferred
 # from the platform.
 #
-if ($PlatformListZ180 -contains $Platform) {$CPUType = "180"} else {$CPUType = "80"}
+$CPUType = "80"
+if ($PlatformListZ180 -contains $Platform) {$CPUType = "180"}
+if ($PlatformListZ280 -contains $Platform) {$CPUType = "280"}
 
 #
 # The $RomName variable determines the name of the image created by the script.  By default,
diff --git a/Source/HBIOS/z280.inc b/Source/HBIOS/z280.inc
index e2aea667..453e1539 100644
--- a/Source/HBIOS/z280.inc
+++ b/Source/HBIOS/z280.inc
@@ -72,16 +72,3 @@ Z280_CT2_CFG	.EQU	$F8	; COUNTER/TIMER 2 CONFIG REG
 Z280_CT2_CMDST	.EQU	$F9	; COUNTER/TIMER 2 COMMAND/STATUS REG
 Z280_CT2_TC	.EQU	$FA	; COUNTER/TIMER 2 TIME CONSTANT
 Z280_CT2_CT	.EQU	$FB	; COUNTER/TIMER 2 COUNT TIME
-;
-; Z280 INSTRUCTIONS (INCOMPLETE, JUST THE ONES USED)
-;
-.ADDINSTR	PCACHE	""	65ED	2 NOP 1
-.ADDINSTR	LDCTL	(C),HL	6EED	2 NOP 1
-.ADDINSTR	LDCTL	HL,(C)	66ED	2 NOP 1
-.ADDINSTR	IM	3	4EED	2 NOP 1
-.ADDINSTR	LDCTL	USP,HL	8FED	2 NOP 1
-.ADDINSTR	LDCTL	IY,(C)	66EDFD	3 NOP 1
-.ADDINSTR	LDCTL	(C),IY	6EEDFD	3 NOP 1
-.ADDINSTR	MULTU	A,*	F9EDFD	4 NOP 1
-.ADDINSTR	LD2	HL,(HL)	26ED	2 NOP 1
-.ADDINSTR	LD2	(HL),DE	1EED	2 NOP 1
diff --git a/Source/HBIOS/z2u.asm b/Source/HBIOS/z2u.asm
index 275ffbe1..7ead843c 100644
--- a/Source/HBIOS/z2u.asm
+++ b/Source/HBIOS/z2u.asm
@@ -199,7 +199,7 @@ Z2U_INTRCV1:
 Z2U_INTRCV2:
 	INC	HL			; HL NOW HAS ADR OF HEAD PTR
 	PUSH	HL			; SAVE ADR OF HEAD PTR
-	LD2	HL,(HL)			; DEREFERENCE HL, HL IS NOW ACTUAL HEAD PTR
+	LD	HL,(HL)			; DEREFERENCE HL, HL IS NOW ACTUAL HEAD PTR
 	LD	(HL),B			; SAVE CHARACTER RECEIVED IN BUFFER AT HEAD
 	INC	HL			; BUMP HEAD POINTER
 	POP	DE			; RECOVER ADR OF HEAD PTR
@@ -215,7 +215,7 @@ Z2U_INTRCV2:
 	INC	HL			; ... SO HL NOW HAS ADR OF ACTUAL BUFFER START
 Z2U_INTRCV3:
 	EX	DE,HL			; DE := HEAD PTR VAL, HL := ADR OF HEAD PTR
-	LD2	(HL),DE			; SAVE UPDATED HEAD PTR
+	LD	(HL),DE			; SAVE UPDATED HEAD PTR
 
 	; CHECK FOR MORE PENDING...
 	IN	A,(Z280_UARTRCTL)	; GET STATUS
diff --git a/Source/ver.inc b/Source/ver.inc
index 09ba0f52..39f2d6eb 100644
--- a/Source/ver.inc
+++ b/Source/ver.inc
@@ -2,4 +2,4 @@
 #DEFINE	RMN	1
 #DEFINE	RUP	1
 #DEFINE	RTP	0
-#DEFINE BIOSVER	"3.1.1-pre.48"
+#DEFINE BIOSVER	"3.1.1-pre.49"
diff --git a/Source/ver.lib b/Source/ver.lib
index 8687f19a..3fd16099 100644
--- a/Source/ver.lib
+++ b/Source/ver.lib
@@ -3,5 +3,5 @@ rmn	equ	1
 rup	equ	1
 rtp	equ	0
 biosver	macro
-	db	"3.1.1-pre.48"
+	db	"3.1.1-pre.49"
 	endm