the pc's parallel port.htm

Parallel Port description of the communication port

        <P><A 
        href="http://support.microsoft.com/support/kb/articles/Q160/1/29.asp?LN=EN-US&amp;SD=gn&amp;FR=0">HOWTO: 
        Get the Status of a Printer and a Print Job</A>. Article ID: Q160129. 
        From Microsoft.</P>
        <LI>
        <P><A href="http://www.fixyourownprinter.com/">Do-it-yourself printer 
        repair</A>.</P></LI></UL>
      <H3><FONT face="Arial, Helvetica, sans-serif"><A 
      name=ConnectingTwoPCs></A>Connecting Two PCs</FONT></H3>
      <P>Connecting two PCs via their parallel ports requires a special cable. 
      For software, you can use Windows 95/98's Direct Cable Connection, a 
      third-party product, or write your own program to do the transfers. To 
      find out about Direct Cable Connection, click F1 on the desktop and search 
      for Direct Cable Connection.</P>
      <UL>
        <LI><A href="http://www.kime.net/directcc/index.html">The Connect 
        Pages</A> have information on how to connect two PCs running various 
        combinations of operating systems, using serial and parallel ports. From 
        Kime.Net. 
        <LI>Symantec is one of many sources for the <A 
        href="http://service1.symantec.com/SUPPORT/ghost.nsf/docid/1998121609495725">pinout 
        for a LapLink cable</A> used in PC-to-PC transfers. 
        <LI>Sewell Development's <A href="http://www.sewelld.com/">Fast Lynx</A> 
        works with everything from DOS through Windows 2000. 
        <LI><A 
        href="http://www.laplink.com/products/llgold/overview.asp">Laplink</A> 
        and <A 
        href="http://enterprisesecurity.symantec.com/products/products.cfm?productID=2">pcAnywhere</A> 
        support PC-to-PC transfers. 
        <LI>Also see the information under <A 
        href="http://www.lvr.com/parport.htm#Cables">Cables</A> below. </LI></UL>
      <H2><A name="Enhanced and Extended Ports"></A><FONT 
      face=Helvetica>Enhanced and Extended Ports</FONT></H2>
      <P>Including the bidirectional (PS/2) port, extended capabilities port 
      (ECP), and enhanced parallel port (EPP), and the IEEE-1284 standard that 
      descibes them all.</P>
      <H3><FONT face="Arial, Helvetica, sans-serif">General 
      Information</FONT></H3>
      <UL>
        <LI>A table showing the <A 
        href="http://www.lvr.com/files/pppinout.pdf">pinouts</A> of all three of 
        the commonly used parallel-port connectors, including the 25-pin D-sub, 
        the 36-contact Centronics connector, and the new IEEE-1284C connector. 
        (6K PDF (Acrobat)&nbsp;file) 
        <LI>Windows 2000 includes improved drivers for accessing parallel-port 
        devices. The driver supports SPP, PS/2 (Byte), EPP, and ECP modes and 
        daisy-chaining. Parclass is a system class driver for parallel-port 
        devices, and Parport is a system function driver for the parallel port. 
        The <A href="http://www.microsoft.com/ddk/">Windows DDK</A> has details. 
        Search for <I>Parallel Devices and Drivers</I> in the index. 
        <LI><A name="Warp Nine Engineering"></A><A 
        href="http://www.fapo.com/">Warp Nine Engineering</A>. Detailed 
        descriptions of the EPP, ECP, and other IEEE-1284 modes. Warp Nine's 
        products include ECP/EPP parallel-port cards, EPP&nbsp;and ECP drivers, 
        and a peripheral interface controller that provides the logic between a 
        general-purpose microcontroller and a PC's parallel port, to enable a 
        peripheral to support EPP&nbsp;and ECP modes. Also check here for the 
        latest information on IEEE standards relating to the parallel port. And 
        there's a link to <A 
        href="http://www.fapo.com/files/ecp_reg.pdf">Microsoft's document 
        describing ECP mode</A>. (325k, PDF file). 
        <LI>Various files relating to the IEEE-1284 standard, from <A 
        href="ftp://ftp.lexmark.com/pub/ieee/">Lexmark's FTP site</A> 
        <LI>Information on ordering standards from <A 
        href="http://stdsbbs.ieee.org/">IEEE</A>. The title of the parallel port 
        standard is <I>1284-1994 IEEE Standard Signaling Method for a 
        Bidirectional Parallel Peripheral Interface for Personal Computers</I>. 
        <LI>Paul Rademacher has a page describing his experience with <A 
        href="http://www.cs.unc.edu/~tracker/tech/epp.html">programming an EPP 
        link</A> using one of Far Point's parallel-port cards. 
        <LI><A href="http://www.smsc.com/ftpdocs/chips.html">Standard 
        Microsystems Corp.</A> has preliminary versions of the daisy-chain 
        specification and EPP BIOS, plus drivers and source code for SMC chips. 
        <LI><A 
        href="http://www.qualitylogic.com/genoa_test_tools/interface_guide.html">QualityLogic</A> 
        (formerly Genoa Technology) has a protocol analyzer and test suite for 
        IEEE-1284 links as well as a variety of products for printer testing. 
        <LI><A href="http://www.transdigital.net/">Trans Digital</A> has a 
        high-speed universal parallel-port product. </LI></UL>
      <H2><A name=Chips></A><FONT face=Helvetica>Chips</FONT></H2>
      <P>The data sheets for parallel-port controller chips include timing 
      diagrams, register assignments, and other useful details about accessing 
      and using the new modes. <I>PC-side</I> chips are for use in PCs; 
      <I>peripheral-side</I> chips are for use in peripherals. 
      <UL>
        <LI><A 
        href="http://www.amd.com/products/lpd/techdocs/techdocs.html">AMD's 
        Am29202 processor</A>, for use in EPP/ECP (peripheral-side). 
        <LI><A 
        href="http://www.cirrus.com/products/categories/multiproto.html">Cirrus 
        Logic</A>'s parallel I/O chips. 
        <LI><A href="http://www.holtek.com.tw/docum/Computer/6535.htm">Holtek's 
        HT6535</A> SPP/EPP/ECP Controller. (PC-side) 
        <LI><A 
        href="http://www.intel.com/design/periphrl/datashts/290486.HTM">Intel's 
        82091</A> advanced integrated peripheral (PC side). 
        <LI>National Semiconductor has a variety of <A 
        href="http://www.national.com/catalog/AdvancedIOProducts.html">Super 
        I/O</A> chips that include an IEEE 1284-compatible parallel port with 
        EPP and ECP modes. (PC-side) 
        <LI><A 
        href="http://www.fairchildsemi.com/pf/74/74VHC161284.html">Fairchild's 
        74VHC161284 Transceiver</A> contains eight bidirectional data buffers 
        and eleven control/status buffers to implement an IEEE-1284 Level 2 
        interface. Outputs on the cable side can be configured to be either open 
        drain or push-pull. 
        <LI><A href="http://www.smsc.com/">Standard Microsystems Corp.,</A> 
        (SMSC), another manufacturer of EPP/ECP parallel-port chips. (PC- and 
        peripheral-side). 
        <LI><A 
        href="http://www.exar.com/cgi-bin/prodtree2.pl?cat=all">Exar/Startech</A>'s 
        ST78C34 and ST78C36 are EPP/ECP&nbsp;chips. Look under 
        Products/Communications/General Purpose. (PC-side). 
        <LI><A 
        href="http://www.ti.com/sc/docs/msp/irda/selguide.htm#pir552">Texas 
        Instruments' TL16PIR552</A> includes a PC-side ECP+EPP, plus a dual UART 
        and IrDa interface. 
        <LI><A href="http://www.fapo.com/1284pic.htm">Warp Nine's W91284PIC</A> 
        supports all modes, plus daisy-chaining and negotiating. 
        (peripheral-side) 
        <LI><A href="http://www.winbond.com.tw/produ/perso5.htm">Winbond</A> has 
        PC-side chips. </LI></UL>
      <H2><A name=Cables></A><FONT face=Helvetica>Cables</FONT></H2>
      <UL>
        <LI>Denis Kondakov has figured out <A 
        href="http://www.lvr.com/files/ecp-dcc.zip">how to do Direct Cable 
        Connection ECP transfers between PCs</A> using a simple, home-brewed 
        cable configuration. It requires a patch to paralink.vxd (zip file, 
        36k). 
        <LI><A href="http://www.lpt.com/lpt/">Parallel Technologies'</A> 
        Universal Cable contains active circuits for high-speed parallel-port 
        communications using Windows 95/98's Direct Cable Connection. 
        <LI>Trans Digital's <A href="http://www.transdigital.net/">Universal 
        Parallel Port</A> is a high-speed, long-distance link between 
        parallel-port peripherals and a PC-ard (PCMCIA) slot. 
        <LI>If you want to connect your parallel printer to a USB port, CableMAX 
        has a <A href="http://www.cablemax.com/cablemax/157.html">USB printer 
        adapter</A> that supports bidirectional printer communications. (Most 
        other adapters don't.) </LI></UL>
      <H2><FONT face="Arial, Helvetica, sans-serif">Various Projects</FONT></H2>
      <P>Projects that use the parallel port or an I/O chip like the 8255 
      Parallel Peripheral Interface chip. </P>
      <UL>
        <LI><A 
        href="http://csel.cs.colorado.edu/~boggs/pbus/pbus.html">Connecting an 
        8255 Parallel Peripheral Interface to the parallel port</A>. From Adam 
        Boggs. 
        <LI><A href="http://www.boondog.com/\tutorials\8255\8255.htm">Connecting 
        an 8255 Parallel Peripheral Interface to the ISA bus</A>. From Boondog 
        Automation. 
        <LI><A href="http://www.pjrc.com/tech/8051/ide/wesley.html">How to 
        connect an IDE disk to a microcontroller using an 8255</A>. by Peter 
        Faasse. I've included this one because of many requests for info about 
        IDE interfacing. 
        <LI>GKDesign's <A 
        href="http://www.geocities.com/SiliconValley/Lakes/7156/">Universal IR 
        Controller for a PC</A> includes source code and a circuit for reading 
        and sending infrared remote-control signals via the parallel port. 
      </LI></UL>
      <H2><A name=Programming></A><FONT face=Helvetica>Programming</FONT></H2>
      <P>There are several ways to access the parallel port and other I/O ports 
      in PCs, including direct I/O, custom device drivers, and Windows' built-in 
      drivers..</P>
      <P>Under Windows 3.x/95/98, applications can read and write directly to 
      port addresses. Use your compiler's built-in functions (<EM>inp</EM> and 
      <EM>out</EM> or similar) or in-line assembly code. (See the source code in 
      <EM>inpout32.zip</EM> below for an example.) This method is simple, but 
      it's slow, it can't protect the port from access by other applications, 
      and it doesn't work at all under NT or Windows 2000. If you use Visual 
      Basic or another language that doesn't have functions for port I/O or 
      allow in-line assembly, you can use a DLL or a custom control that adds 
      port I/O functions to an application.</P>
      <P>A system-level device driver enables faster port access and can manage 
      access by multiple applications. Driver types include VxD (virtual device 
      driver) for Windows 9x, WDM for Windows 98/NT/2000, and kernel-mode driver 
      for Windows NT/2000. Hardware interrupts must use a system-level driver 
      under Windows 9x/NT/2000. If you don't want to write your own driver, 
      there are custom controls and other tools that enable applications to