it is actually more about how SAGE clears files and what happens if that file is missing or tied up.. By added the extra open it was able to recreate it if it was missing.
01032 LET E1$=NAME$,E1=CHANNEL; OPEN (E1,ERR=*NEXT)E1$; CLOSE (E1); ERASE E1$,ERR=*NEXT; OPEN (E1,ERR=*NEXT)E1$; CLOSE (E1)
01035 IF ERR=12 THEN GOTO 1049 ELSE LET E1$=NAME$; ERASE E1$
01049 IF %SYS_WDX THEN WAIT 1
01050 CALL ""SYDEFN"",PATH$,NAME$,TYP$,KEY,RECS,BYTES,E,S2$