Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site unc.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!mcnc!unc!colbert From: colbert@unc.UUCP (Darylene Colbert) Newsgroups: net.micro.pc Subject: PC AT Communications Problem Message-ID: <56@unc.UUCP> Date: Tue, 15-Jan-85 14:59:35 EST Article-I.D.: unc.56 Posted: Tue Jan 15 14:59:35 1985 Date-Received: Fri, 18-Jan-85 01:51:12 EST Organization: CS Dept., U. of N. Carolina at Chapel Hill Lines: 22 I have written an interrupt driven communications program that works fine on the XT but fails under certain conditions on the AT. These conditions are: 1. High volume of transmission & received data at high baud rates (4800 or 9600 baud) 2. Any kind of receiver error (such as a parity error). I use all four possible communications interrupts (receive data available, transmit buffer empty, line status, and modem status). I have tested a few other programs that are similar to mine and they all failed on the AT except one that used only the receive data interrupt. One that failed is a program from IBM! I tried putting delays after every I/O port access; but the longer I made the delays, the more pronounced the problem became! The symptom is an apparent shutdown of the RS232 interrupt system. After the screwup, I never get a communications interrupt again. I am at the end of my rope. Can anyone give me a clue? Thanks Edmund Burnette