diff --git a/Source/HBIOS/Config/RCEZ80_std.asm b/Source/HBIOS/Config/RCEZ80_std.asm
index a2d33aed..f5a95c4c 100644
--- a/Source/HBIOS/Config/RCEZ80_std.asm
+++ b/Source/HBIOS/Config/RCEZ80_std.asm
@@ -45,7 +45,7 @@ EZ80UARTENABLE	.SET	TRUE		; EZ80UART: ENABLE EZ80 UART DRIVER (EZ80UART.ASM)
 LPTENABLE	.SET	FALSE		; LPT: ENABLE CENTRONICS PRINTER DRIVER (LPT.ASM)
 ;
 TMSENABLE	.SET	TRUE		; TMS: ENABLE TMS9918 VIDEO/KBD DRIVER (TMS.ASM)
-TMSTIMENABLE	.SET	FALSE		; TMS: ENABLE TIMER INTERRUPTS (REQUIRES IM1)
+TMSTIMENABLE	.SET	TRUE		; TMS: ENABLE TIMER INTERRUPTS (REQUIRES IM1)
 TMSMODE		.SET	TMSMODE_MSX9958	; TMS: DRIVER MODE: TMSMODE_[SCG|N8|MBC|MSX|MSX9958|MSXKBD|COLECO]
 MKYENABLE	.SET	FALSE		; MSX 5255 PPI KEYBOARD COMPATIBLE DRIVER (REQUIRES TMS VDA DRIVER)
 VRCENABLE	.SET	FALSE		; VRC: ENABLE VGARC VIDEO/KBD DRIVER (VRC.ASM)
diff --git a/Source/HBIOS/cfg_rcez80.asm b/Source/HBIOS/cfg_rcez80.asm
index 0c172d11..817eb23d 100644
--- a/Source/HBIOS/cfg_rcez80.asm
+++ b/Source/HBIOS/cfg_rcez80.asm
@@ -31,7 +31,7 @@ AUTOCON		.EQU	TRUE		; ENABLE CONSOLE TAKEOVER AT LOADER PROMPT
 CPUSPDCAP	.EQU	SPD_FIXED	; CPU SPEED CHANGE CAPABILITY SPD_FIXED|SPD_HILO
 CPUSPDDEF	.EQU	SPD_HIGH	; CPU SPEED DEFAULT SPD_UNSUP|SPD_HIGH|SPD_LOW
 CPUOSC		.EQU	18432000	; CPU OSC FREQ IN MHZ
-INTMODE		.EQU	0		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2, 3=MODE 3 (Z280)
+INTMODE		.EQU	1		; INTERRUPTS: 0=NONE, 1=MODE 1, 2=MODE 2, 3=MODE 3 (Z280)
 DEFSERCFG	.EQU	SER_115200_8N1 | SER_RTS	; DEFAULT SERIAL LINE CONFIG (SEE STD.ASM)
 ;
 RAMSIZE		.EQU	512		; SIZE OF RAM IN KB (MUST MATCH YOUR HARDWARE!!!)
diff --git a/Source/HBIOS/hbios.asm b/Source/HBIOS/hbios.asm
index 9983e7d1..30bb4887 100644
--- a/Source/HBIOS/hbios.asm
+++ b/Source/HBIOS/hbios.asm
@@ -357,6 +357,9 @@ RTCDEF	.SET	RTCDEF | %00001000	; INITIAL SPEED LOW
   #DEFINE EZ80_IO	.DB 	$49, $CF	; RST.L $08
   #DEFINE EZ80_FN 	.DB	$49, $D7	; RST.L $10
   #DEFINE EZ80_BNKSEL 	.DB	$49, $DF	; RST.L $18
+
+  #DEFINE RET.L		.DB	$49 \ RET
+
 #ELSE
   #DEFINE EZ80_IO
 #ENDIF
@@ -1178,7 +1181,7 @@ HBX_INT:	; COMMON INTERRUPT ROUTING CODE
 HBX_RETI:
 	RETI
 ;
-  #ELSE
+  #ELSE ; (MEMMGR == MM_Z280)
 ;
 ; COMMON INTERRUPT DISPATCHING CODE
 ; SETUP AND CALL HANDLER IN BIOS BANK
@@ -1216,16 +1219,23 @@ HBX_INT_SP	.EQU	$ - 2
 ;
 	POP	HL			; RESTORE HL
 ;
+
+#IF (CPUFAM == CPU_EZ80)
+	RET.L				; INTERRUPTS WILL BE ENABLED BY BY EZ80 FIRMWARE
+					; CAN THEY BE ENABLED HERE - DOES THAT RISK RE-ENTRANT OF THE HANDLER?
+#ELSE
 	HB_EI				; ENABLE INTERRUPTS
 	RETI				; AND RETURN
+#ENDIF
+
 ;
-  #ENDIF
+  #ENDIF ; END ELSE IF (MEMMGR == MM_Z280)
 ;
-#ELSE
+#ELSE ; #IF (INTMODE > 0)
 ;
 	RET
 ;
-#ENDIF
+#ENDIF ; #END ELSE IF (INTMODE > 0)
 ;
 ; SMALL TEMPORARY STACK FOR USE BY HBX_BNKCPY
 ;