So as an update and as a request for more assistance . . .
I have tried to read 8 bits of data using status and control ports. I
shifted my lower nibble of the desired 8 bits differently than my pin out
chart listed before. I have changed to model after this:
http://www.beyondlogic.org/spp/parallel.htm#7
"No luck". I should clarify by saying "not complete success". However, I
don't know if the chip is good for this or not either. That may be good
news or bad news. :)
I have the status port of PC #2 accepting bit changes from data port of
PC #1. However, no matter what I do, I cannot change the values of the
control port of PC #2 from outside of PC #2.
I am explicitly telling how to get this executable to compile for posterity
and for those who may not know how. I have attached some source files I
wrote for this test. To compile the executable, put the 4 attached files in
a directory. At the console prompt in that directory, type "make", (without
parenthesis). This while yield the executable "sim.x". To run the program
at the console, type "./sim.x" plus the number of loops to read the ports.
It assumes that the kernel has parport and parport_pc. The executable will
load and unload ppdev.o and its only real purpose is to see and manipulate
the bits of the respective ports...
I have two parallel port cards in my PC so I am simulating both PC's on a
single computer. I have tried several W83787F chip boards and a couple
others types. I connect them with the cable as described on the link above
but also here:
PC PC
1 - 2 <-
2 - 1 ->
3 - 14 ->
4 - 16 ->
5 - 17 ->
6 - 13
7 - 12
8 - 10
9 - 11
10 - 8
11 - 9
12 - 7
13 - 6
14 - 3 <-
15 - 15
16 - 4 <-
17 - 5 <-
18 - 18
19 - 19
20 - 20
21 - 21
22 - 22
23 - 23
24 - 24
25 - 25
Note: The arrows above indicate my open collector inverters.
I am using 5.6 K resisters in front of the transistors to make my open
collector logic and I know it works, (should sink a couple hundred
milliamps)
So I have been able to set my data lines to the values I wish. I can see my
status bits PC#2 change when I set data bits on PC#1 but not control bits.
So I am able to probe the open collector logic and it looks correct. When I
drive pin 2 high on either PC, I see the other side sink low and vice versa.
However, the software isn't seeing the change. So what I am thinking is
that the values are being held either by hardware or software despite the
values changing on the pins. Is this a driver thing? Is it a chip thing?
Did I miss some driver documentation on toggling the control from output to
input?
Thank You,
Nate Jenkins
----- Original Message -----
From: "Blaise Gassend" <blaise@gassend.com>
To: "Nate Jenkins" <nate@uniwest.com>
Cc: <linux-parport@torque.net>; "Gregg C Levine"
<yodathejediknight@worldnet.att.net>
Sent: Monday, April 21, 2003 11:10 AM
Subject: Re: [PARPORT] custom cabling
> If you are worried about damaging your parallel port, just put a
> suitable resistor on lines that might both be outputs at the same time.
> That way, if they both try to drive the line, the resistor will limit
> the current to a safe value.
>
> Blaise
>
> Quoted from Nate Jenkins on Mon, Apr 21, 2003 at 10:47:44AM -0700.
> > Thanks for your input,
> >
> > I just found a few extra ISA parallel port cards laying around here.
Maybe
> > I'll have to try it on one of those. I didn't want to attempt to
destroy
> > the parport on the mother board, for fear I might render the mother
board
> > useless. I know, no guts, no glory. If I blow up an ISA card, that
might
> > be fun. I'll let you know how it goes when I try. It may be a couple
of
> > weeks, depending on how it goes around here.
> >
> > Nate
> >
> >
> > ----- Original Message -----
> > From: "Gregg C Levine" <yodathejediknight@worldnet.att.net>
> > To: "Nate Jenkins" <nate@uniwest.com>; <linux-parport@torque.net>
> > Cc: "Blaise Gassend" <blaise@gassend.com>
> > Sent: Saturday, April 19, 2003 6:01 PM
> > Subject: Re: [PARPORT] custom cabling
> >
> >
> > > Hello from Gregg C Levine
> > > I, too, looked at the site. I also have one of the Lap Link Turbo
cables,
> > > made by Belkin. It works, under an OS made by the Evil Empire.
However, to
> > > get it to work under Linux, using, say, PLIP functions would take an
act
> > of
> > > God, or somebody because it did not work for me, even after filing a
> > > particular How To note. I think the Beyond Logic data, is
questionable,
> > not
> > > your interpretations of them. How about you, Nate, keep working on it,
and
> > > report back?
> > > Gregg C Levine yodathejediknight@att.net or
> > > yodathejediknight@worldnet.att.net
> > > "May the Force be with you!"
> > > ----- Original Message -----
> > > From: "Nate Jenkins" <nate@uniwest.com>
> > > To: <linux-parport@torque.net>
> > > Cc: "Blaise Gassend" <blaise@gassend.com>
> > > Sent: Friday, April 18, 2003 12:59 PM
> > > Subject: Re: [PARPORT] custom cabling
> > >
> > >
> > > > Blaise, et al.
> > > >
> > > > I appreciate your input. I have tried to not disregard the fact
that
> > some
> > > > pins are input and others are output. Maybe my source is
> > questionable...
> > > >
> > > > http://www.beyondlogic.org/spp/parallel.htm
> > > >
> > > >
> > > > Hardware Properties
> > > > .
> > > > .<some copy snipped>
> > > > .
> > > > Pin No (D-Type 25) Pin No (Centronics) SPP Signal Direction
> > In/out
> > > > Register Hardware Inverted
> > > > 1 1 nStrobe In/Out Control Yes
> > > > 2 2 Data 0 Out Data
> > > > 3 3 Data 1 Out Data
> > > > 4 4 Data 2 Out Data
> > > > 5 5 Data 3 Out Data
> > > > 6 6 Data 4 Out Data
> > > > 7 7 Data 5 Out Data
> > > > 8 8 Data 6 Out Data
> > > > 9 9 Data 7 Out Data
> > > > 10 10 nAck In Status
> > > > 11 11 Busy In Status Yes
> > > > 12 12 Paper-Out / Paper-End In Status
> > > > 13 13 Select In Status
> > > > 14 14 nAuto-Linefeed In/Out Control Yes
> > > > 15 32 nError / nFault In Status
> > > > 16 31 nInitialize In/Out Control
> > > > 17 36 nSelect-Printer / nSelect-In In/Out Control Yes
> > > > 18 - 25 19-30 Ground Gnd
> > > >
> > > > Table 1. Pin Assignments of the D-Type 25 pin Parallel Port
Connector.
> > > >
> > > >
> > > > Specifically, on nStrobe, I read that it could be used for input or
> > > output.
> > > > This is why I thought, it may be fine to connect. Is this not
correct?
> > > >
> > > > I know I have tested with reading and writing to the
data/status/control
> > > > ports to see which bits I can use for outputting to the other PC
using a
> > > > LapLink cable. I think I double checked my pin assignments before I
> > > > originally sent my inquiry to the list. Am I off? Where I am not
> > certain
> > > > is if I will damage hardware before attempting such a feat.
> > > >
> > > > Regarding an 8 bit cable, I have only seen the cable at
> > http://www.lpt.com
> > > > for 8 bit transfer. However, they will not even think about
allowing
> > > their
> > > > products to deviate from the world of M$. I have talked to them a
few
> > > times
> > > > about Linux support and they inferred that they cannot as if they
were
> > > being
> > > > watched right then by big brother... I think they have some extra
> > > circuitry
> > > > in the cable to buffer and do some crossing over. That is why the
cable
> > > is
> > > > faster and very software dependent...
> > > >
> > > >
> > > > Thank You,
> > > >
> > > > Nate Jenkins
> > > >
> > > > United Western Technologies
> > > > Software Engineer
> > > > http://www.uniwest.com
> > > >
> > > > nate@uniwest.com
> > > > Ph: (509) 544-0720
> > > > Fx: (509) 544-0868
> > > >
> > > >
> > > > NOTICE: This email may contain confidential or privileged material
and
> > > > is intended for use solely by the above-referenced recipient. Any
> > > > review, copying, printing, disclosure, distribution, or other use
> > > > by any other person or entity is strictly prohibited. If you
> > > > are not the named recipient, or believe you have
> > > > received this email in error, please reply
> > > > to the sender and delete the copy
> > > > you received. Thank you.
> > > >
> > > >
> > > > ----- Original Message -----
> > > > From: "Blaise Gassend" <blaise@gassend.com>
> > > > To: "Nate Jenkins" <nate@uniwest.com>
> > > > Cc: <linux-parport@torque.net>
> > > > Sent: Thursday, April 17, 2003 4:11 PM
> > > > Subject: Re: [PARPORT] custom cabling
> > > >
> > > >
> > > > > > **Proposed Custom Cable Map**
> > > > > > D7 - ~S7 , (09-11) , [data7-busy]
> > > > > > D6 - S6 , (08-10) , [data6-nAck]
> > > > > > D5 - S5 , (07-12) , [data5-paper]
> > > > > > D4 - S4 , (06-13) , [data4-select]
> > > > > > D3 - S3 , (05-15) , [data3-error]
> > > > > > D2 - ~C3 , (04-17) , [data2-nSelPrntr]
> > > > > > D1 - C2 , (03-16) , [data1-nInit]
> > > > > > D0 - ~C1 , (02-14) , [data0-nAutoLF]
> > > > > > ~C0 - ~C0 , (01-01) , [nStrobe-nStrobe]
> > > > >
> > > > > It seems to me like you are disregarding the fact that some pins
are
> > > > > inputs and others are outputs. For example, connecting nStrobe to
> > > > > nStrobe won't work because they are both of the same type.
> > > > >
> > > > > I think there are some common designs for 8 bit parallel cables.
They
> > > > > connect the data lines to the data lines (on recent parallel ports
the
> > > > > data lines are usually bidirectional) and use the unidirectional
> > signals
> > > > > for handshaking. I don't have a link to a precise description of
one
> > of
> > > > > these cables, but I expect that a little googling should help. I
also
> > > > > expect that the software for these cables is already available.
> > > > >
> > > > > Blaise
> > > > >
> > > >
> > > >
> > > > -- To unsubscribe, send mail to:
linux-parport-request@torque.net --
> > > > -- with the single word "unsubscribe" in the body of the
message. --
> > > >
> > >
> > >
> >
> >
> > -- To unsubscribe, send mail to: linux-parport-request@torque.net --
> > -- with the single word "unsubscribe" in the body of the message. --
> >
>
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This archive was generated by hypermail 2b29 : Mon May 12 2003 - 18:38:21 EDT