€•ãjŒsphinx.addnodes”Œdocument”“”)”}”(Œ rawsource”Œ”Œchildren”]”(Œ translations”Œ LanguagesNode”“”)”}”(hhh]”(hŒ pending_xref”“”)”}”(hhh]”Œdocutils.nodes”ŒText”“”ŒChinese (Simplified)”…””}”Œparent”hsbaŒ attributes”}”(Œids”]”Œclasses”]”Œnames”]”Œdupnames”]”Œbackrefs”]”Œ refdomain”Œstd”Œreftype”Œdoc”Œ reftarget”Œ#/translations/zh_CN/networking/plip”Œmodname”NŒ classname”NŒ refexplicit”ˆuŒtagname”hhh ubh)”}”(hhh]”hŒChinese (Traditional)”…””}”hh2sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/zh_TW/networking/plip”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒItalian”…””}”hhFsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/it_IT/networking/plip”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒJapanese”…””}”hhZsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/ja_JP/networking/plip”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒKorean”…””}”hhnsbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/ko_KR/networking/plip”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒPortuguese (Brazilian)”…””}”hh‚sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/pt_BR/networking/plip”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubh)”}”(hhh]”hŒSpanish”…””}”hh–sbah}”(h]”h ]”h"]”h$]”h&]”Œ refdomain”h)Œreftype”h+Œ reftarget”Œ#/translations/sp_SP/networking/plip”Œmodname”NŒ classname”NŒ refexplicit”ˆuh1hhh ubeh}”(h]”h ]”h"]”h$]”h&]”Œcurrent_language”ŒEnglish”uh1h hhŒ _document”hŒsource”NŒline”NubhŒcomment”“”)”}”(hŒ SPDX-License-Identifier: GPL-2.0”h]”hŒ SPDX-License-Identifier: GPL-2.0”…””}”hh·sbah}”(h]”h ]”h"]”h$]”h&]”Œ xml:space”Œpreserve”uh1hµhhh²hh³Œ=/var/lib/git/docbuild/linux/Documentation/networking/plip.rst”h´KubhŒsection”“”)”}”(hhh]”(hŒtitle”“”)”}”(hŒ0PLIP: The Parallel Line Internet Protocol Device”h]”hŒ0PLIP: The Parallel Line Internet Protocol Device”…””}”(hhÏh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhhÊh²hh³hÇh´KubhŒ paragraph”“”)”}”(hŒVDonald Becker (becker@super.org) I.D.A. Supercomputing Research Center, Bowie MD 20715”h]”(hŒDonald Becker (”…””}”(hhßh²hh³Nh´NubhŒ reference”“”)”}”(hŒbecker@super.org”h]”hŒbecker@super.org”…””}”(hhéh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”Œmailto:becker@super.org”uh1hçhhßubhŒ7) I.D.A. Supercomputing Research Center, Bowie MD 20715”…””}”(hhßh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KhhÊh²hubhÞ)”}”(hŒWAt some point T. Thorn will probably contribute text, Tommy Thorn (tthorn@daimi.aau.dk)”h]”(hŒCAt some point T. Thorn will probably contribute text, Tommy Thorn (”…””}”(hjh²hh³Nh´Nubhè)”}”(hŒtthorn@daimi.aau.dk”h]”hŒtthorn@daimi.aau.dk”…””}”(hj h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”Œrefuri”Œmailto:tthorn@daimi.aau.dk”uh1hçhjubhŒ)”…””}”(hjh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K hhÊh²hubhÉ)”}”(hhh]”(hÎ)”}”(hŒPLIP Introduction”h]”hŒPLIP Introduction”…””}”(hj(h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhj%h²hh³hÇh´KubhÞ)”}”(hŒ½This document describes the parallel port packet pusher for Net/LGX. This device interface allows a point-to-point connection between two parallel ports to appear as a IP network interface.”h]”hŒ½This document describes the parallel port packet pusher for Net/LGX. This device interface allows a point-to-point connection between two parallel ports to appear as a IP network interface.”…””}”(hj6h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´Khj%h²hubhÉ)”}”(hhh]”(hÎ)”}”(hŒ What is PLIP?”h]”hŒ What is PLIP?”…””}”(hjGh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhjDh²hh³hÇh´KubhÞ)”}”(hXkPLIP is Parallel Line IP, that is, the transportation of IP packages over a parallel port. In the case of a PC, the obvious choice is the printer port. PLIP is a non-standard, but [can use] uses the standard LapLink null-printer cable [can also work in turbo mode, with a PLIP cable]. [The protocol used to pack IP packages, is a simple one initiated by Crynwr.]”h]”hXkPLIP is Parallel Line IP, that is, the transportation of IP packages over a parallel port. In the case of a PC, the obvious choice is the printer port. PLIP is a non-standard, but [can use] uses the standard LapLink null-printer cable [can also work in turbo mode, with a PLIP cable]. [The protocol used to pack IP packages, is a simple one initiated by Crynwr.]”…””}”(hjUh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KhjDh²hubeh}”(h]”Œ what-is-plip”ah ]”h"]”Œ what is plip?”ah$]”h&]”uh1hÈhj%h²hh³hÇh´KubhÉ)”}”(hhh]”(hÎ)”}”(hŒAdvantages of PLIP”h]”hŒAdvantages of PLIP”…””}”(hjnh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhjkh²hh³hÇh´KubhÞ)”}”(hŒ5It's cheap, it's available everywhere, and it's easy.”h]”hŒ;It’s cheap, it’s available everywhere, and it’s easy.”…””}”(hj|h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K!hjkh²hubhÞ)”}”(hŒgThe PLIP cable is all that's needed to connect two Linux boxes, and it can be built for very few bucks.”h]”hŒiThe PLIP cable is all that’s needed to connect two Linux boxes, and it can be built for very few bucks.”…””}”(hjŠh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K#hjkh²hubhÞ)”}”(hŒêConnecting two Linux boxes takes only a second's decision and a few minutes' work, no need to search for a [supported] netcard. This might even be especially important in the case of notebooks, where netcards are not easily available.”h]”hŒîConnecting two Linux boxes takes only a second’s decision and a few minutes’ work, no need to search for a [supported] netcard. This might even be especially important in the case of notebooks, where netcards are not easily available.”…””}”(hj˜h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K&hjkh²hubhÞ)”}”(hŒ¡Not requiring a netcard also means that apart from connecting the cables, everything else is software configuration [which in principle could be made very easy.]”h]”hŒ¡Not requiring a netcard also means that apart from connecting the cables, everything else is software configuration [which in principle could be made very easy.]”…””}”(hj¦h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K+hjkh²hubeh}”(h]”Œadvantages-of-plip”ah ]”h"]”Œadvantages of plip”ah$]”h&]”uh1hÈhj%h²hh³hÇh´KubhÉ)”}”(hhh]”(hÎ)”}”(hŒDisadvantages of PLIP”h]”hŒDisadvantages of PLIP”…””}”(hj¿h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhj¼h²hh³hÇh´K0ubhÞ)”}”(hŒÖDoesn't work over a modem, like SLIP and PPP. Limited range, 15 m. Can only be used to connect three (?) Linux boxes. Doesn't connect to an existing Ethernet. Isn't standard (not even de facto standard, like SLIP).”h]”hŒÜDoesn’t work over a modem, like SLIP and PPP. Limited range, 15 m. Can only be used to connect three (?) Linux boxes. Doesn’t connect to an existing Ethernet. Isn’t standard (not even de facto standard, like SLIP).”…””}”(hjÍh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K2hj¼h²hubeh}”(h]”Œdisadvantages-of-plip”ah ]”h"]”Œdisadvantages of plip”ah$]”h&]”uh1hÈhj%h²hh³hÇh´K0ubhÉ)”}”(hhh]”(hÎ)”}”(hŒ Performance”h]”hŒ Performance”…””}”(hjæh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhjãh²hh³hÇh´K8ubhÞ)”}”(hŒ^PLIP easily outperforms Ethernet cards....(ups, I was dreaming, but it *is* getting late. EOB)”h]”(hŒGPLIP easily outperforms Ethernet cards....(ups, I was dreaming, but it ”…””}”(hjôh²hh³Nh´NubhŒemphasis”“”)”}”(hŒ*is*”h]”hŒis”…””}”(hjþh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jühjôubhŒ getting late. EOB)”…””}”(hjôh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K:hjãh²hubeh}”(h]”Œ performance”ah ]”h"]”Œ performance”ah$]”h&]”uh1hÈhj%h²hh³hÇh´K8ubeh}”(h]”Œplip-introduction”ah ]”h"]”Œplip introduction”ah$]”h&]”uh1hÈhhÊh²hh³hÇh´KubhÉ)”}”(hhh]”(hÎ)”}”(hŒPLIP driver details”h]”hŒPLIP driver details”…””}”(hj)h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhj&h²hh³hÇh´K>ubhÞ)”}”(hŒÊThe Linux PLIP driver is an implementation of the original Crynwr protocol, that uses the parallel port subsystem of the kernel in order to properly share parallel ports between PLIP and other services.”h]”hŒÊThe Linux PLIP driver is an implementation of the original Crynwr protocol, that uses the parallel port subsystem of the kernel in order to properly share parallel ports between PLIP and other services.”…””}”(hj7h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K@hj&h²hubhÉ)”}”(hhh]”(hÎ)”}”(hŒIRQs and trigger timeouts”h]”hŒIRQs and trigger timeouts”…””}”(hjHh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhjEh²hh³hÇh´KEubhÞ)”}”(hŒÑWhen a parallel port used for a PLIP driver has an IRQ configured to it, the PLIP driver is signaled whenever data is sent to it via the cable, such that when no data is available, the driver isn't being used.”h]”hŒÓWhen a parallel port used for a PLIP driver has an IRQ configured to it, the PLIP driver is signaled whenever data is sent to it via the cable, such that when no data is available, the driver isn’t being used.”…””}”(hjVh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KGhjEh²hubhÞ)”}”(hXÝHowever, on some machines it is hard, if not impossible, to configure an IRQ to a certain parallel port, mainly because it is used by some other device. On these machines, the PLIP driver can be used in IRQ-less mode, where the PLIP driver would constantly poll the parallel port for data waiting, and if such data is available, process it. This mode is less efficient than the IRQ mode, because the driver has to check the parallel port many times per second, even when no data at all is sent. Some rough measurements indicate that there isn't a noticeable performance drop when using IRQ-less mode as compared to IRQ mode as far as the data transfer speed is involved. There is a performance drop on the machine hosting the driver.”h]”hXßHowever, on some machines it is hard, if not impossible, to configure an IRQ to a certain parallel port, mainly because it is used by some other device. On these machines, the PLIP driver can be used in IRQ-less mode, where the PLIP driver would constantly poll the parallel port for data waiting, and if such data is available, process it. This mode is less efficient than the IRQ mode, because the driver has to check the parallel port many times per second, even when no data at all is sent. Some rough measurements indicate that there isn’t a noticeable performance drop when using IRQ-less mode as compared to IRQ mode as far as the data transfer speed is involved. There is a performance drop on the machine hosting the driver.”…””}”(hjdh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KKhjEh²hubhÞ)”}”(hXKWhen the PLIP driver is used in IRQ mode, the timeout used for triggering a data transfer (the maximal time the PLIP driver would allow the other side before announcing a timeout, when trying to handshake a transfer of some data) is, by default, 500usec. As IRQ delivery is more or less immediate, this timeout is quite sufficient.”h]”hXKWhen the PLIP driver is used in IRQ mode, the timeout used for triggering a data transfer (the maximal time the PLIP driver would allow the other side before announcing a timeout, when trying to handshake a transfer of some data) is, by default, 500usec. As IRQ delivery is more or less immediate, this timeout is quite sufficient.”…””}”(hjrh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KVhjEh²hubhÞ)”}”(hXxWhen in IRQ-less mode, the PLIP driver polls the parallel port HZ times per second (where HZ is typically 100 on most platforms, and 1024 on an Alpha, as of this writing). Between two such polls, there are 10^6/HZ usecs. On an i386, for example, 10^6/100 = 10000usec. It is easy to see that it is quite possible for the trigger timeout to expire between two such polls, as the timeout is only 500usec long. As a result, it is required to change the trigger timeout on the *other* side of a PLIP connection, to about 10^6/HZ usecs. If both sides of a PLIP connection are used in IRQ-less mode, this timeout is required on both sides.”h]”(hXØWhen in IRQ-less mode, the PLIP driver polls the parallel port HZ times per second (where HZ is typically 100 on most platforms, and 1024 on an Alpha, as of this writing). Between two such polls, there are 10^6/HZ usecs. On an i386, for example, 10^6/100 = 10000usec. It is easy to see that it is quite possible for the trigger timeout to expire between two such polls, as the timeout is only 500usec long. As a result, it is required to change the trigger timeout on the ”…””}”(hj€h²hh³Nh´Nubjý)”}”(hŒ*other*”h]”hŒother”…””}”(hjˆh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jühj€ubhŒ™ side of a PLIP connection, to about 10^6/HZ usecs. If both sides of a PLIP connection are used in IRQ-less mode, this timeout is required on both sides.”…””}”(hj€h²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K\hjEh²hubhÞ)”}”(hŒøIt appears that in practice, the trigger timeout can be shorter than in the above calculation. It isn't an important issue, unless the wire is faulty, in which case a long timeout would stall the machine when, for whatever reason, bits are dropped.”h]”hŒúIt appears that in practice, the trigger timeout can be shorter than in the above calculation. It isn’t an important issue, unless the wire is faulty, in which case a long timeout would stall the machine when, for whatever reason, bits are dropped.”…””}”(hj h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KfhjEh²hubhÞ)”}”(hXA utility that can perform this change in Linux is plipconfig, which is part of the net-tools package (its location can be found in the Documentation/Changes file). An example command would be 'plipconfig plipX trigger 10000', where plipX is the appropriate PLIP device.”h]”hXA utility that can perform this change in Linux is plipconfig, which is part of the net-tools package (its location can be found in the Documentation/Changes file). An example command would be ‘plipconfig plipX trigger 10000’, where plipX is the appropriate PLIP device.”…””}”(hj®h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KkhjEh²hubeh}”(h]”Œirqs-and-trigger-timeouts”ah ]”h"]”Œirqs and trigger timeouts”ah$]”h&]”uh1hÈhj&h²hh³hÇh´KEubeh}”(h]”Œplip-driver-details”ah ]”h"]”Œplip driver details”ah$]”h&]”uh1hÈhhÊh²hh³hÇh´K>ubhÉ)”}”(hhh]”(hÎ)”}”(hŒPLIP hardware interconnection”h]”hŒPLIP hardware interconnection”…””}”(hjÏh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhjÌh²hh³hÇh´KrubhÞ)”}”(hŒþPLIP uses several different data transfer methods. The first (and the only one implemented in the early version of the code) uses a standard printer "null" cable to transfer data four bits at a time using data bit outputs connected to status bit inputs.”h]”hXPLIP uses several different data transfer methods. The first (and the only one implemented in the early version of the code) uses a standard printer “null†cable to transfer data four bits at a time using data bit outputs connected to status bit inputs.”…””}”(hjÝh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KthjÌh²hubhÞ)”}”(hŒùThe second data transfer method relies on both machines having bi-directional parallel ports, rather than output-only ``printer`` ports. This allows byte-wide transfers and avoids reconstructing nibbles into bytes, leading to much faster transfers.”h]”(hŒvThe second data transfer method relies on both machines having bi-directional parallel ports, rather than output-only ”…””}”(hjëh²hh³Nh´NubhŒliteral”“”)”}”(hŒ ``printer``”h]”hŒprinter”…””}”(hjõh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jóhjëubhŒx ports. This allows byte-wide transfers and avoids reconstructing nibbles into bytes, leading to much faster transfers.”…””}”(hjëh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KyhjÌh²hubhÉ)”}”(hhh]”(hÎ)”}”(hŒParallel Transfer Mode 0 Cable”h]”hŒParallel Transfer Mode 0 Cable”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhj h²hh³hÇh´KubhÞ)”}”(hX¼The cable for the first transfer mode is a standard printer "null" cable which transfers data four bits at a time using data bit outputs of the first port (machine T) connected to the status bit inputs of the second port (machine R). There are five status inputs, and they are used as four data inputs and a clock (data strobe) input, arranged so that the data input bits appear as contiguous bits with standard status register implementation.”h]”hXÀThe cable for the first transfer mode is a standard printer “null†cable which transfers data four bits at a time using data bit outputs of the first port (machine T) connected to the status bit inputs of the second port (machine R). There are five status inputs, and they are used as four data inputs and a clock (data strobe) input, arranged so that the data input bits appear as contiguous bits with standard status register implementation.”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´Khj h²hubhÞ)”}”(hŒÈA cable that implements this protocol is available commercially as a "Null Printer" or "Turbo Laplink" cable. It can be constructed with two DB-25 male connectors symmetrically connected as follows::”h]”hŒÏA cable that implements this protocol is available commercially as a “Null Printer†or “Turbo Laplink†cable. It can be constructed with two DB-25 male connectors symmetrically connected as follows:”…””}”(hj,h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K‰hj h²hubhŒ literal_block”“”)”}”(hX„STROBE output 1* D0->ERROR 2 - 15 15 - 2 D1->SLCT 3 - 13 13 - 3 D2->PAPOUT 4 - 12 12 - 4 D3->ACK 5 - 10 10 - 5 D4->BUSY 6 - 11 11 - 6 D5,D6,D7 are 7*, 8*, 9* AUTOFD output 14* INIT output 16* SLCTIN 17 - 17 extra grounds are 18*,19*,20*,21*,22*,23*,24* GROUND 25 - 25 * Do not connect these pins on either end”h]”hX„STROBE output 1* D0->ERROR 2 - 15 15 - 2 D1->SLCT 3 - 13 13 - 3 D2->PAPOUT 4 - 12 12 - 4 D3->ACK 5 - 10 10 - 5 D4->BUSY 6 - 11 11 - 6 D5,D6,D7 are 7*, 8*, 9* AUTOFD output 14* INIT output 16* SLCTIN 17 - 17 extra grounds are 18*,19*,20*,21*,22*,23*,24* GROUND 25 - 25 * Do not connect these pins on either end”…””}”hj<sbah}”(h]”h ]”h"]”h$]”h&]”hÅhÆuh1j:h³hÇh´Khj h²hubhÞ)”}”(hŒtIf the cable you are using has a metallic shield it should be connected to the metallic DB-25 shell at one end only.”h]”hŒtIf the cable you are using has a metallic shield it should be connected to the metallic DB-25 shell at one end only.”…””}”(hjJh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´Kœhj h²hubeh}”(h]”Œparallel-transfer-mode-0-cable”ah ]”h"]”Œparallel transfer mode 0 cable”ah$]”h&]”uh1hÈhjÌh²hh³hÇh´KubhÉ)”}”(hhh]”(hÎ)”}”(hŒParallel Transfer Mode 1”h]”hŒParallel Transfer Mode 1”…””}”(hjch²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhj`h²hh³hÇh´K ubhÞ)”}”(hX¾The second data transfer method relies on both machines having bi-directional parallel ports, rather than output-only ``printer`` ports. This allows byte-wide transfers, and avoids reconstructing nibbles into bytes. This cable should not be used on unidirectional ``printer`` (as opposed to ``parallel``) ports or when the machine isn't configured for PLIP, as it will result in output driver conflicts and the (unlikely) possibility of damage.”h]”(hŒvThe second data transfer method relies on both machines having bi-directional parallel ports, rather than output-only ”…””}”(hjqh²hh³Nh´Nubjô)”}”(hŒ ``printer``”h]”hŒprinter”…””}”(hjyh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jóhjqubhŒ‰ ports. This allows byte-wide transfers, and avoids reconstructing nibbles into bytes. This cable should not be used on unidirectional ”…””}”(hjqh²hh³Nh´Nubjô)”}”(hŒ ``printer``”h]”hŒprinter”…””}”(hj‹h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jóhjqubhŒ (as opposed to ”…””}”(hjqh²hh³Nh´Nubjô)”}”(hŒ ``parallel``”h]”hŒparallel”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1jóhjqubhŒ) ports or when the machine isn’t configured for PLIP, as it will result in output driver conflicts and the (unlikely) possibility of damage.”…””}”(hjqh²hh³Nh´Nubeh}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K¢hj`h²hubhÞ)”}”(hŒCThe cable for this transfer mode should be constructed as follows::”h]”hŒBThe cable for this transfer mode should be constructed as follows:”…””}”(hjµh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´Kªhj`h²hubj;)”}”(hXaSTROBE->BUSY 1 - 11 D0->D0 2 - 2 D1->D1 3 - 3 D2->D2 4 - 4 D3->D3 5 - 5 D4->D4 6 - 6 D5->D5 7 - 7 D6->D6 8 - 8 D7->D7 9 - 9 INIT -> ACK 16 - 10 AUTOFD->PAPOUT 14 - 12 SLCT->SLCTIN 13 - 17 GND->ERROR 18 - 15 extra grounds are 19*,20*,21*,22*,23*,24* GROUND 25 - 25 * Do not connect these pins on either end”h]”hXaSTROBE->BUSY 1 - 11 D0->D0 2 - 2 D1->D1 3 - 3 D2->D2 4 - 4 D3->D3 5 - 5 D4->D4 6 - 6 D5->D5 7 - 7 D6->D6 8 - 8 D7->D7 9 - 9 INIT -> ACK 16 - 10 AUTOFD->PAPOUT 14 - 12 SLCT->SLCTIN 13 - 17 GND->ERROR 18 - 15 extra grounds are 19*,20*,21*,22*,23*,24* GROUND 25 - 25 * Do not connect these pins on either end”…””}”hjÃsbah}”(h]”h ]”h"]”h$]”h&]”hÅhÆuh1j:h³hÇh´K¬hj`h²hubhÞ)”}”(hŒ€Once again, if the cable you are using has a metallic shield it should be connected to the metallic DB-25 shell at one end only.”h]”hŒ€Once again, if the cable you are using has a metallic shield it should be connected to the metallic DB-25 shell at one end only.”…””}”(hjÑh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K¾hj`h²hubeh}”(h]”Œparallel-transfer-mode-1”ah ]”h"]”Œparallel transfer mode 1”ah$]”h&]”uh1hÈhjÌh²hh³hÇh´K ubhÉ)”}”(hhh]”(hÎ)”}”(hŒPLIP Mode 0 transfer protocol”h]”hŒPLIP Mode 0 transfer protocol”…””}”(hjêh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÍhjçh²hh³hÇh´KÂubhÞ)”}”(hŒŒThe PLIP driver is compatible with the "Crynwr" parallel port transfer standard in Mode 0. That standard specifies the following protocol::”h]”hŒThe PLIP driver is compatible with the “Crynwr†parallel port transfer standard in Mode 0. That standard specifies the following protocol:”…””}”(hjøh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KÄhjçh²hubj;)”}”(hŒXsend header nibble '0x8' count-low octet count-high octet ... data octets checksum octet”h]”hŒXsend header nibble '0x8' count-low octet count-high octet ... data octets checksum octet”…””}”hjsbah}”(h]”h ]”h"]”h$]”h&]”hÅhÆuh1j:h³hÇh´KÇhjçh²hubhÞ)”}”(hŒEach octet is sent as::”h]”hŒEach octet is sent as:”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KÍhjçh²hubj;)”}”(hŒf >4)&0x0F)>”h]”hŒf >4)&0x0F)>”…””}”hj"sbah}”(h]”h ]”h"]”h$]”h&]”hÅhÆuh1j:h³hÇh´KÏhjçh²hubhÞ)”}”(hŒ×To start a transfer the transmitting machine outputs a nibble 0x08. That raises the ACK line, triggering an interrupt in the receiving machine. The receiving machine disables interrupts and raises its own ACK line.”h]”hŒ×To start a transfer the transmitting machine outputs a nibble 0x08. That raises the ACK line, triggering an interrupt in the receiving machine. The receiving machine disables interrupts and raises its own ACK line.”…””}”(hj0h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´KÒhjçh²hubhÞ)”}”(hŒ Restated::”h]”hŒ Restated:”…””}”(hj>h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hÝh³hÇh´K×hjçh²hubj;)”}”(hŒ®(OUT is bit 0-4, OUT.j is bit j from OUT. IN likewise) Send_Byte: OUT := low nibble, OUT.4 := 1 WAIT FOR IN.4 = 1 OUT := high nibble, OUT.4 := 0 WAIT FOR IN.4 = 0”h]”hŒ®(OUT is bit 0-4, OUT.j is bit j from OUT. IN likewise) Send_Byte: OUT := low nibble, OUT.4 := 1 WAIT FOR IN.4 = 1 OUT := high nibble, OUT.4 := 0 WAIT FOR IN.4 = 0”…””}”hjLsbah}”(h]”h ]”h"]”h$]”h&]”hÅhÆuh1j:h³hÇh´KÙhjçh²hubeh}”(h]”Œplip-mode-0-transfer-protocol”ah ]”h"]”Œplip mode 0 transfer protocol”ah$]”h&]”uh1hÈhjÌh²hh³hÇh´KÂubeh}”(h]”Œplip-hardware-interconnection”ah ]”h"]”Œplip hardware interconnection”ah$]”h&]”uh1hÈhhÊh²hh³hÇh´Krubeh}”(h]”Œ/plip-the-parallel-line-internet-protocol-device”ah ]”h"]”Œ0plip: the parallel line internet protocol device”ah$]”h&]”uh1hÈhhh²hh³hÇh´Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”hÇuh1hŒcurrent_source”NŒ current_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(hÍNŒ generator”NŒ datestamp”NŒ source_link”NŒ source_url”NŒ toc_backlinks”Œentry”Œfootnote_backlinks”KŒ sectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒ strip_classes”NŒ report_level”KŒ halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ traceback”ˆŒinput_encoding”Œ utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”j•Œerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œ language_code”Œen”Œrecord_dependencies”NŒconfig”NŒ id_prefix”hŒauto_id_prefix”Œid”Œ dump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”hÇŒ _destination”NŒ _config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒ raw_enabled”KŒline_length_limit”M'Œpep_references”NŒ pep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒ rfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œ smart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œ docinfo_xform”KŒsectsubtitle_xform”‰Œ image_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”(jojlj#j jhjej¹j¶jàjÝjjjÉjÆjÁj¾jgjdj]jZjäjáj_j\uŒ nametypes”}”(jo‰j#‰jh‰j¹‰jà‰j‰jɉjÁ‰jg‰j]‰jä‰j_‰uh}”(jlhÊj j%jejDj¶jkjÝj¼jjãjÆj&j¾jEjdjÌjZj jáj`j\jçuŒ footnote_refs”}”Œ citation_refs”}”Œ autofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ footnotes”]”Œ citations”]”Œautofootnote_start”KŒsymbol_footnote_start”KŒ id_counter”Œ collections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œ transformer”NŒ include_log”]”Œ decoration”Nh²hub.