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From: CHEM194@canterbury.ac.nz (J.DAVIS)
Newsgroups: comp.sys.ibm.pc
Subject: Re: INPUT PARALLEL DATA OVER THE PRINTER PORT?
Message-ID: <7730@canterbury.ac.nz>
Date: 30 May 90 15:38:23 GMT
References: <7459@arctic.nprdc.arpa> <2010023@hpctdls.HP.COM> <12548@netcom.UUCP> <3260@galena2.UUCP>
Lines: 46

> Parallel input *IS* possible on all PC's. - BUT (here it comes) as has been
> stated you cant use the 8 outputs. The parallel interface does have four
> inputs used by printers to indicate BUISY, PAPEROUT, ONLINE, etc. it is
> possible to use these and with some software jigery-pokery, multiplex two
> nibbles. OK its not quite 8 bits parallel but 4 bits parallel can still
> run faster than serial at 115Kbaud. This is (I think flame on if i'm wrong)
> the mechanism used by Laplink and other software that uses input from parallel
> ports.

well, I'm sitting here looking at a PC technical ( hardware ) reference,
and this is what it's got to say

"output to address 03bch ( for mono graphics/printer adaptor ) or
                   0378h ( for printer card )
 
 this instruction captures the data from the data bus and sends it
 to the respective ( data ) pins on the printer adaptor. i.e bits
 0-7 on pins 2-9 respectively "

"input from address 03bch ( for mono graphics/printer adaptor ) or
                    0378h ( for printer card )
 
 this instruction gets data from the pins on the adaptor on to
 the data bus in a similar way to the out instruction on the 
 dame adress"
 
Sure looks like fully bi-directional 8-bit to me ....
 
> ----------------------------------------------------------------------------
>              Justin Smith   SYSOP- Orange Crush BBS  (708) 359-5379
>                         24 Hours USRobotics HST14400/V.32
> Email UUNET smithju@motcid.uu.net  INTERNET motcid!smithju@chg.mcd.mot.com  


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