What is(are) the difference(s) between the 1542a and the 1542b? -- Phone: (work) 219-482-9631; MCI mail: DFEUSTEL E-mail: feustel at well.sf.ca.us {ucbvax,apple,hplabs,pacbell}!well!feustel USMAIL: Dave Feustel, 1930 Curdes Ave, Fort Wayne, IN 46805-2710