Update std.asm

Source/HBIOS/std.asm

@@ -349,6 +349,53 @@ CPUKHZ		.SET	CPUKHZ * 2	; ADJUST FOR DOUBLE SPEED OPERATION
 ;
 CPUMHZ		.EQU	CPUKHZ / 1000	; CPU FREQ IN MHZ
 ;
+; SYSTEM PERIODIC TIMER MODE
+;
+#IF (BIOS == BIOS_WBW)
+;
+TM_NONE	.EQU	0
+TM_CTC	.EQU	1
+TM_TMS	.EQU	2
+TM_SIMH	.EQU	3
+TM_Z180	.EQU	4
+;
+	.ECHO "SYSTEM TIMER:"
+SYSTIM	.EQU	TM_NONE
+;
+  #IF (CTCENABLE & (INTMODE == 2))
+    #IF (CTCTIMER)
+SYSTIM	.SET	TM_CTC
+	.ECHO	" CTC"
+    #ENDIF
+  #ENDIF
+;
+  #IF (TMSENABLE & (INTMODE == 1))
+    #IF (TMSTIMENABLE)
+SYSTIM	.SET	TM_TMS
+	.ECHO	" TMS9918"
+    #ENDIF
+  #ENDIF
+;
+  #IF ((PLATFORM == PLT_SBC) & (INTMODE == 1))
+    #IF (HTIMENABLE)
+SYSTIM	.SET	TM_SIMH
+	.ECHO	" SIMH"
+    #ENDIF
+  #ENDIF
+;
+  #IF ((CPUFAM == CPU_Z180) & (INTMODE == 2))
+SYSTIM	.SET	TM_Z180
+	.ECHO	" Z180"
+  #ENDIF
+;
+  #IF SYSTIM == TM_NONE
+	.ECHO " NONE"
+  #ENDIF
+;
+	.ECHO	"\n"
+;
+#ENDIF
+;
 ; MEMORY BANK CONFIGURATION
 ;
 #IF (BIOS == BIOS_UNA)