Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!steinmetz!davidsen From: davidsen@steinmetz.steinmetz.UUCP (William E. Davidsen Jr) Newsgroups: comp.sys.ibm.pc Subject: Re: Interrupt's for the COM ports on a PS/2 model 50 Message-ID: <8139@steinmetz.steinmetz.UUCP> Date: Tue, 8-Dec-87 21:35:16 EST Article-I.D.: steinmet.8139 Posted: Tue Dec 8 21:35:16 1987 Date-Received: Sun, 13-Dec-87 17:29:48 EST References: <16803@gatech.edu> <132@babbage.acc.virginia.edu> Reply-To: davidsen@crdos1.UUCP (bill davidsen) Organization: General Electric CRD, Schenectady, NY Lines: 14 Keywords: interrupts,serial,com,port,pia In article <132@babbage.acc.virginia.edu> mac3n@babbage.acc.virginia.edu (Alex Colvin) writes: | The 8259 triggers interrupts off the IRQ lines either by edge or by level. | In the PC it's edge, making it hard to share IRQ lines. | I believe this changed to level in the PS/2. I tried a number of communication programs, both internally written and other, and they ran on the PS/2. There is a bit in the 8259 which selects edge or level trigger, but it may be initialized diferently by the BIOS software (you do initialize everything, right?) in the PS/2. -- bill davidsen (wedu@ge-crd.arpa) {uunet | philabs | seismo}!steinmetz!crdos1!davidsen "Stupidity, like virtue, is its own reward" -me