Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!necntc!ames!elroy!cit-vax!ucla-cs!zen!ucbvax!cbosgd!mandrill!neoucom!wtm From: wtm@neoucom.UUCP (Bill Mayhew) Newsgroups: comp.sys.ibm.pc Subject: Re: Interrupt's for the COM ports on a PS/2 model 50 Message-ID: <821@neoucom.UUCP> Date: Sun, 6-Dec-87 23:38:47 EST Article-I.D.: neoucom.821 Posted: Sun Dec 6 23:38:47 1987 Date-Received: Sun, 13-Dec-87 01:04:39 EST References: <16803@gatech.edu> <132@babbage.acc.virginia.edu> Organization: Northeastern Ohio Universities College of Medicine Lines: 25 Keywords: interrupts,serial,com,port,pia Summary: PS/2 PIC *is* level triggered Just a few days ago, I has this question and talked to a knowledgable person as SCO. He confirmed that in the PS/2 level triggering is used. Just to keep life interesting, I suppose. I have the PS/2 BIOS manual, and don't recall seeing that documented, but them I haven't finished absorbing every single word there yet. He also mentioned relative to the model 80 that if a '387 fpu is installed that the system can hang totally if a lot of floating point is going on at the same time as a long DMA xfer (like to disk for instance). Intel has announced that this is indeed a bug with the '386 to '387 interface. Apparently it can be remedied by the addition of a few SSI gates on some control lines between the '386 and '387. How easy it would be to fix on a model 80, I don't know. I have used a model 80 owned by an associate that *does* have a '387 and have not yet seen the aforementioned bug. (knock on wood...) Unlike the other PS/2 models, I am impressed with the 80. It is a nicely assembled box. The 70 meg *IBM made* ESDI disk is quite a screamer too. Quite a nice product; now if I only had the $$$. One of the nicer aspects of the 80 is that it doesn't sound like a miniature wind tunnel next to the desk; in fact it is barely audible. --Bill