diff --git a/sources/Z80.pas b/sources/Z80.pas
index b12f5a7..3bb97be 100644
--- a/sources/Z80.pas
+++ b/sources/Z80.pas
@@ -127,20 +127,20 @@ 	TZ80 = record
 	PZ80 = ^TZ80;
 
 const
-	Z80_OPTION_LD_A_IR_BUG = 1;
-	Z80_OPTION_OUT_VC_255  = 2;
+	Z80_OPTION_OUT_VC_255  = 1;
+	Z80_OPTION_LD_A_IR_BUG = 2;
 	Z80_OPTION_XQ          = 8;
 	Z80_OPTION_YQ          = 32;
 	Z80_OPTION_HALT_SKIP   = 64;
 	Z80_MODEL_ZILOG_NMOS   = (Z80_OPTION_LD_A_IR_BUG or Z80_OPTION_XQ or Z80_OPTION_YQ);
 	Z80_MODEL_ZILOG_CMOS   = (Z80_OPTION_OUT_VC_255 or Z80_OPTION_XQ or Z80_OPTION_YQ);
 	Z80_MODEL_NEC_NMOS     = Z80_OPTION_LD_A_IR_BUG;
-	Z80_MODEL_ST_CMOS      = (Z80_OPTION_LD_A_IR_BUG or Z80_OPTION_YQ);
+	Z80_MODEL_ST_CMOS      = (Z80_OPTION_OUT_VC_255 or Z80_OPTION_LD_A_IR_BUG or Z80_OPTION_YQ);
 
-	Z80_REQUEST_SPECIAL_RESET = 1;
 	Z80_REQUEST_REJECT_NMI    = 2;
 	Z80_REQUEST_NMI           = 4;
 	Z80_REQUEST_INT           = 8;
+	Z80_REQUEST_SPECIAL_RESET = 16;
 
 	Z80_RESUME_HALT     = 1;
 	Z80_RESUME_XY       = 2;