* paralel port - doesn't keep pins states @ 2003-04-06 23:16 filip 2003-04-15 14:47 ` Alexandru Damian 0 siblings, 1 reply; 2+ messages in thread From: filip @ 2003-04-06 23:16 UTC (permalink / raw) To: linux-kernel Hello, I hope it is the right place to ask about my problem... I want to use /dev/lp0 (lp module) on my PC for controlling external devices. The problem is when I wtire 1 byte to /dev/lp0, paralel port keeps this state just for few ms... (I made special plug - so the is no problem with handshake - details on: http://www.hut.fi/Misc/Electronics/circuits/nullprint.html) It is strange because everything works corect on my old PC (Pentium160). Regards, Filip ^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: paralel port - doesn't keep pins states 2003-04-06 23:16 paralel port - doesn't keep pins states filip @ 2003-04-15 14:47 ` Alexandru Damian 0 siblings, 0 replies; 2+ messages in thread From: Alexandru Damian @ 2003-04-15 14:47 UTC (permalink / raw) To: filip; +Cc: linux-kernel filip wrote: >Hello, > >I hope it is the right place to ask about my problem... > >I want to use /dev/lp0 (lp module) on my PC for controlling >external devices. >The problem is when I wtire 1 byte to /dev/lp0, paralel port >keeps this state just for few ms... >(I made special plug - so the is no problem with handshake - details on: >http://www.hut.fi/Misc/Electronics/circuits/nullprint.html) > > It's normal, since the parallel -port specification clearly states that the port doesn't maintain the pins voltage more than a minimum mandatory delay, and while setting, the state is undefined. >It is strange because everything works corect on my old PC (Pentium160). > That was broken hardware, it didn't meet the specifications :)) > >Regards, >Filip >- >To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html >Please read the FAQ at http://www.tux.org/lkml/ > > > > ^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2003-04-15 14:34 UTC | newest] Thread overview: 2+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2003-04-06 23:16 paralel port - doesn't keep pins states filip 2003-04-15 14:47 ` Alexandru Damian
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