; FIRST.ACT  --  a few odd PROCs/FUNCs››;   LegalDrive - allows determining if›       the specified drive number is›       recognized by DOS››;   MaskInput - uses underlines as input›       masking for user responses››;   UnMask - cleans off excess masking›       that the editor picks up››;   Find - returns the position in a›       CHAR ARRAY (string) where the›       sub-string was found, returns›       0 if not found - search begins›       at the position specified by›       start› ›; ------------------------------------›       ›BYTE FUNC LegalDrive(BYTE drive_num)›BYTE drvbyt=$070A, bit, i›BYTE ARRAY mask=[1 2 4 8 16 32 64 128], drive(8)›  FOR bit=0 TO 7›  DO›    drive(bit)=(drvbyt&mask(bit)) RSH bit›  OD›RETURN(drive(drive_num-1))››PROC MaskInput(BYTE width)›BYTE i›  FOR i=1 TO width›  DO›    Put('_)›  OD›  FOR i=1 TO width›  DO›    Put(')›  OD›RETURN››PROC UnMask(CHAR ARRAY source,destination)›BYTE i›  FOR i=1 TO source(0)›  DO›    IF source(i)<>'_ THEN›      destination(i)=source(i)›    ELSE›      EXIT›    FI›  OD›  destination(0)=i-1›RETURN››BYTE FUNC Find(CHAR ARRAY str,sub BYTE start)›BYTE i, j›CHAR ARRAY tmp›  FOR i=start TO str(0)›  DO›    IF sub(1)=str(i) THEN›      tmp(0)=sub(0)›      FOR j=1 TO sub(0)›      DO›        tmp(j)=str(j+i-1)›      OD›      IF SCompare(tmp,sub)=0 THEN›        RETURN(i)›      FI›    FI›  OD›RETURN(0)››