diff --git a/constants/ZX_VARS.INC b/constants/ZX_VARS.INC
index cee2363..a8787f1 100644
--- a/constants/ZX_VARS.INC
+++ b/constants/ZX_VARS.INC
@@ -73,6 +73,9 @@ AUTO_5C9A               		EQU #5C9A
 NMI_ADR                 EQU #5CB0
 TOP_CLEAR               EQU #5CB2
 P_RAMTOP                EQU #5CB4
+
+
+;	TR-DOS
 BEG_ADRESS              EQU #5CB6
 RET_INS                 EQU #5CC2
 AUTO_5CC3            			EQU #5CC3
@@ -128,6 +131,7 @@ FST_SYM_NAME            EQU #5D08
 VAR_3                   EQU #5D09
 BUF_FLAG                EQU #5D0C
 BAS_DOS_FLG             EQU #5D0E
+RUN_AUTO_BOOT		EQU #5D0E
 DOS_ERR_2               EQU #5D0F
 ERR_3D00                EQU #5D10
 ADR_DOS_COM             EQU #5D11