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Received: by minnie.vk1xwt.ampr.org with NNTP id AA7834 ; Tue, 26 Jan 93 19:00:21 EST Newsgroups: comp.unix.bsd Path: sserve!manuel.anu.edu.au!munnari.oz.au!spool.mu.edu!uunet!boulder!ucsu!rintintin.Colorado.EDU!galbrait From: galbrait@rintintin.Colorado.EDU (GALBRAITH JOHN) Subject: Re: reading from parallel port Message-ID: <1993Jan26.025455.7032@ucsu.Colorado.EDU> Sender: news@ucsu.Colorado.EDU (USENET News System) Nntp-Posting-Host: rintintin.colorado.edu Organization: University of Colorado, Boulder References: <1jhejv$9l3@Germany.EU.net> <C1ADIM.1s3@sleeper.apana.org.au> Date: Tue, 26 Jan 1993 02:54:55 GMT Lines: 29 In article <C1ADIM.1s3@sleeper.apana.org.au> raz@sleeper.apana.org.au (Roland Turner) writes: >bs@Germany.EU.net (Bernard Steiner) writes: > >>Folks, >>I just read through one of those terrible x86 magazines. Somebody advertized >>their LPT port ethernet[TM] adapter. > >>While I believe that the idea of driving the ethernet through a slow LPT >>port is not really fascinating, I sort of like the idea of using the >>parallel port for "serious work". This would require reading from the >>port, though. > I have built some hardware that read from the parallel port. The problem is that the main data lines are output only. You can read from the port, but it returns the last value that you wrote, not what is currently what you may have put on the port. I did get it to work (I was building a MIDI port for a lab). What I did was to use four control lines from one of the ports that CAN be read and read a nibble at a time. It worked, and was fine for MIDI (A serial interface) but I would imagine that it would be SLOW for an ethernet card. Also, it could be that some newer lpt cards do have bidirectionality. I think the MCA cards do for instance, but I may be wrong. john galbraith galbrait@rintintin.colorado.edu