[fa.info-mac] Control and Status calls?

info-mac@uw-beaver (info-mac) (09/26/84)

From: David.Anderson@CMU-CS-G.ARPA
Could someone out there with the latest Inside Macintosh post a summary
of the Control and Status calls for the serial ports?  All I really
need is a way to find out if there is pending input, but a complete
summary would be wonderful.  

--david