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Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!cronkite.cisco.com!cisco.com!vandys From: vandys@cisco.com (Andrew Valencia) Newsgroups: comp.os.386bsd.questions Subject: Re: ISA strayintr 7 - please help!! Date: 18 Nov 93 02:36:59 GMT Organization: cisco Systems Lines: 18 Message-ID: <vandys.753590219@cisco.com> References: <2c6nga$2e8@darkstar.UCSC.EDU> <wilko.753391395@spoetnix.idca.tds.philips.nl> <2cafgi$rqs@olivaw.apanix.apana.org.au> <2cecj3$g30@usenet.mcs.kent.edu> NNTP-Posting-Host: glare.cisco.com In <2cecj3$g30@usenet.mcs.kent.edu> borsburn@mcs.kent.edu (Bret Orsburn) writes: >In article <2cafgi$rqs@olivaw.apanix.apana.org.au> hart@apanix.apana.org.au (Leigh Hart) writes: >>Printer ports usually have no need for interrupt routines because they >>very rarely are input devices. >Sorry if I'm missing some contextual subtlety here, but this statement is >nonsense. Lots of output devices use interrupts. You're both right. In the case of PC parallel ports, many interface cards do not interrupt reliably, thus polling drivers were written. The "interruptless" LP driver uses some clever adaptive counters to tune itself to your port and printer. Lots of other output devices (the transmit side of RS-232, for instance) do indeed use interrupts even when only operating as output devices. Andy