patch-2.1.67 linux/drivers/net/README1.PLIP
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- Lines: 114
- Date:
Wed Dec 31 16:00:00 1969
- Orig file:
v2.1.66/linux/drivers/net/README1.PLIP
- Orig date:
Wed Aug 10 09:26:00 1994
diff -u --recursive --new-file v2.1.66/linux/drivers/net/README1.PLIP linux/drivers/net/README1.PLIP
@@ -1,113 +0,0 @@
-\title{PLIP: The Parallel Line Internet Protocol Device}
-
-\author{ Donald Becker (becker@super.org)}
-\affiliation{I.D.A. Supercomputing Research Center, Bowie MD 20715}
-
-%% At some point T. Thorn will probably contribute text,
-%% \author{ Tommy Thorn (tthorn@daimi.aau.dk)}
-
-\section{PLIP Introduction}
-This 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.
-
-\chapter{PLIP hardware interconnection}
-PLIP 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 transfers data four bits at a time using
-data bit outputs connected to status bit inputs.
-
-The 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.
-
-\section{Parallel Transfer Mode 0 Cable}
-The 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.
-
-A 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:
-
- 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
-
-If the cable you are using has a metallic shield it should be
-connected to the metallic DB-25 shell at one end only.
-
-\section{Parallel Transfer Mode 1}
-The 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.
-
-The cable for this transfer mode should be constructed as follows:
-
- STROBE->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
-
-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.
-
-\section{PLIP Mode 0 transfer protocol}
-The PLIP driver is compatible with the "Crynwr" parallel port transfer
-standard in Mode 0. That standard specifies the following protocol:
-
- send header nibble '8'
- count-low octet
- count-high octet
- ... data octets
- checksum octet
-
-Each octet is sent as
- <wait for rx. '1'> <send 0x10+(octet&0x0F)>
- <wait for rx. '0'> <send 0x00+((octet>>4)&0x0F)>
-
-To start a transfer the transmitting machine outputs a nibble 0x08.
-The raises the ACK line, triggering an interrupt in the receiving
-machine. The receiving machine disables
-
-Restated:
-
-(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
-
-
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