!TITLE Register corruption on READ SYMBOL

Where the argument to READ SYMBOL is an intrinsic map (ie CHARNO, BYTE, INTEGER,
LENGTH), the address is first calculated, stored in a register, and READ SYMBOL
called. READ SYMBOL may overwrite the register in which the destination address
is stored. The solution is declare a temporary integer to hold the READ SYMBOL

  i.e. change

    READ SYMBOL(BYTE(100))

  into

    READ SYMBOL(C); BYTE(100) = C