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USB to Parallel adapter?
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Charlie Edmondson
electronics forum Guru Wannabe


Joined: 02 May 2005
Posts: 251

PostPosted: Thu Jul 06, 2006 11:54 pm    Post subject: Re: USB to Parallel adapter? Reply with quote

Malcolm Reeves wrote:

Quote:
On Thu, 29 Jun 2006 16:36:18 GMT, nico@puntnl.niks (Nico Coesel)
wrote:


USB doesn't like bitbanging because USB relies on polling. It is
probably much easier to create something that works over ethernet.


At the risk of repeating myself since no one seems to have commented
on my post, the practical solution is to get a PCIMIA card such as
from http://www.transdigital.net/ . I have one and it works with my
Velleman scope and Xilinx parallel cable.

There is no practical general purpose USB solution for all the reasons
mentioned here. Cost wise the PCIMIA solution is similar to Pico USB
adaptor but of course the PCIMIA solution works with all units needing
LPT.

Also, for those on laptops, many laptop manufacturers take a few

'shortcuts' on their parallel port implementations. I don't know how
many times I got a call from some engineer "I just got a new laptop, but
the dongle doesn't work on it!" This was especially true for docking
stations. It seems like they didn't implement all the pins directly,
but multiplex them internally somehow...

Charlie
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Tim Baldwin
electronics forum beginner


Joined: 03 Jul 2006
Posts: 1

PostPosted: Mon Jul 03, 2006 1:03 pm    Post subject: Re: USB to Parallel adapter? Reply with quote

"Malcolm Reeves" <mreeves@fullcircuit.com> wrote in message
news:3jqha259b5lnasj4d5nrsq4fefr6vig4f4@4ax.com...
Quote:
On Thu, 29 Jun 2006 16:36:18 GMT, nico@puntnl.niks (Nico Coesel)
wrote:

USB doesn't like bitbanging because USB relies on polling. It is
probably much easier to create something that works over ethernet.

At the risk of repeating myself since no one seems to have commented
on my post, the practical solution is to get a PCIMIA card such as
from http://www.transdigital.net/ . I have one and it works with my
Velleman scope and Xilinx parallel cable.

There is no practical general purpose USB solution for all the reasons
mentioned here. Cost wise the PCIMIA solution is similar to Pico USB
adaptor but of course the PCIMIA solution works with all units needing
LPT.
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Malcolm Reeves
electronics forum beginner


Joined: 22 May 2005
Posts: 20

PostPosted: Mon Jul 03, 2006 10:05 am    Post subject: Re: USB to Parallel adapter? Reply with quote

On Thu, 29 Jun 2006 16:36:18 GMT, nico@puntnl.niks (Nico Coesel)
wrote:

Quote:
USB doesn't like bitbanging because USB relies on polling. It is
probably much easier to create something that works over ethernet.

At the risk of repeating myself since no one seems to have commented
on my post, the practical solution is to get a PCIMIA card such as
from http://www.transdigital.net/ . I have one and it works with my
Velleman scope and Xilinx parallel cable.

There is no practical general purpose USB solution for all the reasons
mentioned here. Cost wise the PCIMIA solution is similar to Pico USB
adaptor but of course the PCIMIA solution works with all units needing
LPT.
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Nico Coesel
electronics forum Guru Wannabe


Joined: 30 Apr 2005
Posts: 192

PostPosted: Thu Jun 29, 2006 4:36 pm    Post subject: Re: USB to Parallel adapter? Reply with quote

Jim Thompson <To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote:

Quote:
On Tue, 27 Jun 2006 23:05:46 GMT, shb*NO*SPAM*@comporium.net (Si
Ballenger) wrote:

On Tue, 27 Jun 2006 19:15:06 +0100, Terry Pinnell
terrypinDELETE@THESEdial.pipex.com> wrote:

As a PC 'scope in my shed/workshop I use the 'ADC-200/50' from Pico
Technology.
http://www.picotech.com/high-speed-oscilloscopes.html
It's one of their older products and so has a parallel port connector,
not USB like the new stuff.

The ancient W98 PC in the shed is very unreliable I'm replacing it
with a mid-range laptop. But of course that won't have a parallel
socket.

Business grade laptops often have parallel ports (but more $$$).
I'd just get the old computer running again, or get a new fast
box and put a parallel port card in it. The USB to parallel
adapters only work with printers (no bit banging).

I would think that one of you bit-bangers could design a USB-to-LPT
device and then write software to take parallel port commands and
convert them to USB (and back). No?

USB doesn't like bitbanging because USB relies on polling. It is
probably much easier to create something that works over ethernet.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl
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Paul E. Schoen
electronics forum Guru Wannabe


Joined: 01 Jul 2005
Posts: 171

PostPosted: Thu Jun 29, 2006 7:41 am    Post subject: Re: USB to Parallel adapter? Reply with quote

"Rich Grise" <richgrise@example.net> wrote in message
news:pan.2006.06.29.03.18.52.450156@example.net...
Quote:
On Tue, 27 Jun 2006 19:12:42 -0700, Jim Thompson wrote:
On Wed, 28 Jun 2006 01:56:24 GMT, Joerg
Hello Jim,

I would think that one of you bit-bangers could design a USB-to-LPT
device and then write software to take parallel port commands and
convert them to USB (and back). No?

I was told by a (pretty good) Windows programmer that such a task of
near realtime control via USB can quickly turn into a major nightmare.
Deadline is near, stuff don't work, coffee, more coffee, Prozac...

You have to deal with numerous intricacies of Windows, a product that
isn't exactly known for flawlessness. Plus I guess the market potential
for a bitbang capable device would be slim.

So bit-bangers aren't up to analog-level design ?:-)


Ha, ha. It's not the connecting of the dots - it's trying to do _anything
at all_ synchronously on a Windoze OS.

Good Luck!
Rich


Apparently there is a low-level microsecond timer that can be accessed. See
http://www.codeproject.com/cpp/precision_timer.asp for some information.

Here is software that claims 1 millisecond asynchronous event scheduling:
http://www.ryledesign.com/winhrt.html

Here is another good reference page:
http://www.geisswerks.com/ryan/FAQS/timing.html

However, it is probably best to say goodbye to the fading parallel port. In
my case it may be a problem because I have some very expensive software
that is protected by a dongle, and reverts to DEMO mode if it is removed
(Save functions are disabled). I was worried about this in case I lost the
dongle or it stopped working, or having to pay a huge price for a USB
dongle. However, I found the ultimate solution. The VB script has a "Save"
function that is not disabled, so I don't really need the dongle after all!
Hooray for back doors!

Paul
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Rich Grise
electronics forum Guru


Joined: 24 Mar 2005
Posts: 3971

PostPosted: Wed Jun 28, 2006 7:19 pm    Post subject: Re: USB to Parallel adapter? Reply with quote

On Tue, 27 Jun 2006 19:12:42 -0700, Jim Thompson wrote:
Quote:
On Wed, 28 Jun 2006 01:56:24 GMT, Joerg
Hello Jim,

I would think that one of you bit-bangers could design a USB-to-LPT
device and then write software to take parallel port commands and
convert them to USB (and back). No?

I was told by a (pretty good) Windows programmer that such a task of
near realtime control via USB can quickly turn into a major nightmare.
Deadline is near, stuff don't work, coffee, more coffee, Prozac...

You have to deal with numerous intricacies of Windows, a product that
isn't exactly known for flawlessness. Plus I guess the market potential
for a bitbang capable device would be slim.

So bit-bangers aren't up to analog-level design ?:-)


Ha, ha. It's not the connecting of the dots - it's trying to do _anything
at all_ synchronously on a Windoze OS.

Good Luck!
Rich
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Rich Grise
electronics forum Guru


Joined: 24 Mar 2005
Posts: 3971

PostPosted: Wed Jun 28, 2006 7:16 pm    Post subject: Re: USB to Parallel adapter? Reply with quote

On Tue, 27 Jun 2006 19:15:06 +0100, Terry Pinnell wrote:

Quote:
As a PC 'scope in my shed/workshop I use the 'ADC-200/50' from Pico
Technology.
http://www.picotech.com/high-speed-oscilloscopes.html
It's one of their older products and so has a parallel port connector,
not USB like the new stuff.

The ancient W98 PC in the shed is very unreliable I'm replacing it
with a mid-range laptop. But of course that won't have a parallel
socket.

What makes you assume that?

The first three here have parallel ports:
<http://shop4.outpost.com/search?search_type=regular&sqxts=1&query_string=motherboard&cat=&submit.x=0&submit.y=0>
I stuck angle brackets in hopes the link won't wrap.

I know, you don't have Fry's in Britain, but you must have _something_
like it! The motherboards all come from China anyway, after all. :-)

I think probably a whole lot of motherboards still have the
parallel port, it's just that not all desktops load the connector.

A new PS wouldn't hurt either, and a decent operating system. ;-)

Good Luck!
Rich
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Joerg
electronics forum Guru


Joined: 05 May 2005
Posts: 3533

PostPosted: Wed Jun 28, 2006 11:48 am    Post subject: Re: USB to Parallel adapter? Reply with quote

Hello Jim,

Quote:

I would think that one of you bit-bangers could design a USB-to-LPT
device and then write software to take parallel port commands and
convert them to USB (and back). No?

I was told by a (pretty good) Windows programmer that such a task of
near realtime control via USB can quickly turn into a major nightmare.
Deadline is near, stuff don't work, coffee, more coffee, Prozac...

You have to deal with numerous intricacies of Windows, a product that
isn't exactly known for flawlessness. Plus I guess the market potential
for a bitbang capable device would be slim.

So bit-bangers aren't up to analog-level design ?:-)


Bit bangers do not believe there is an analog world. On account of Max
Planck, they say.

--
Regards, Joerg

http://www.analogconsultants.com
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Roger Hamlett
electronics forum Guru


Joined: 28 Apr 2005
Posts: 302

PostPosted: Wed Jun 28, 2006 10:15 am    Post subject: Re: USB to Parallel adapter? Reply with quote

"Jim Thompson" <To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote in
message news:guh3a29m31rdldrea1uofdbft0g27dpbo2@4ax.com...
Quote:
On Tue, 27 Jun 2006 23:05:46 GMT, shb*NO*SPAM*@comporium.net (Si
Ballenger) wrote:

On Tue, 27 Jun 2006 19:15:06 +0100, Terry Pinnell
terrypinDELETE@THESEdial.pipex.com> wrote:

As a PC 'scope in my shed/workshop I use the 'ADC-200/50' from Pico
Technology.
http://www.picotech.com/high-speed-oscilloscopes.html
It's one of their older products and so has a parallel port connector,
not USB like the new stuff.

The ancient W98 PC in the shed is very unreliable I'm replacing it
with a mid-range laptop. But of course that won't have a parallel
socket.

Business grade laptops often have parallel ports (but more $$$).
I'd just get the old computer running again, or get a new fast
box and put a parallel port card in it. The USB to parallel
adapters only work with printers (no bit banging).

I would think that one of you bit-bangers could design a USB-to-LPT
device and then write software to take parallel port commands and
convert them to USB (and back). No?
The problem is that devices like this, do not take 'parallel port

commands', but direct bit I/O, often at high rates. So (for instance), the
driver may issue something like a 1uSec pulse easily when talking directly
to the port, but via the 'time sliced' system used on USB, this becomes
very difficult indeed. The only 'universal' way to do it for output, would
be to use something like a bulk I/O device, and sample the data to be sent
perhaps every uSec, and then send this as a block to the USB device, which
generates the output at the same rate. This however would fail, if the
communication is bidirectional. If (for instance), the local driver
expects to output a bit, and then only a uSec latter, retrieve a 'reply'.
By the time the transmission is packetted up, and sent over USB, then the
reply is received, hundreds of times the expected delay wuld have taken
place. The way it can be done, is to put significant intelligence in the
USB device, and program this to output the required patterns, and retrieve
the data, then send this as a 'non timing critical' transaction over USB.
This can be done, and several companies do such adapters for their older
devices, but it requires a new local driver, and custom code in the USB
device, which makes this a more expensive solution....

Best Wishes
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OBones
electronics forum addict


Joined: 29 Apr 2005
Posts: 93

PostPosted: Wed Jun 28, 2006 9:47 am    Post subject: Re: USB to Parallel adapter? Reply with quote

Look closely, some brand new laptops have the parallel port, but they
most often are in the "desktop replacement" category.
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Terry Pinnell
electronics forum Guru


Joined: 25 Mar 2005
Posts: 376

PostPosted: Wed Jun 28, 2006 9:36 am    Post subject: Re: USB to Parallel adapter? Reply with quote

Many thanks for all those helpful replies. Quite a bit to think about.

Getting the old W98 PC working reliably (perhaps under an alternative
OS such a W2000 as Michael suggests) certainly seems the most cost
effective solution. But, apart from its current unreliability, and my
unwillingness to invest much more time on it, two other factors
favouring a laptop are

- Space; the 17" Ilyama and the largish PC tower would release some
handy room

- I'd like to play with the laptop in house and garden. (Although
this will inevitably increase hassle from my wife about spending too
long at my computer already <g>).

A guy sat down opposite me on the train and opened up his HP laptop -
which had a parallel port. He reckoned it was "a year or so old." So
I'd think seriously about an older notebook, but for the warnings that
even that might not work.

--
Terry Pinnell
Hobbyist, West Sussex, UK
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mc
electronics forum Guru


Joined: 29 Dec 2005
Posts: 475

PostPosted: Wed Jun 28, 2006 3:25 am    Post subject: Re: USB to Parallel adapter? Reply with quote

Quote:
Even if you got a new laptop with a parallel port, the O-scpoe
software might not work with it. Hardware timing with XP will
probably not be as quick and acurate as with win98, and the
software may not have proper drivers to work with XP. I've got
aToshiba laptop with a parallel port, and I haven't been able to
bitbang it as of yet.

Basically, the problem is that XP is a real operating system. 98 will
happily drop down into a mode very much like DOS. XP will not; XP never
gets out of the picture. That is why XP is considerably less crash-prone
than 98.
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Martine Riddle
electronics forum beginner


Joined: 20 Jun 2006
Posts: 14

PostPosted: Wed Jun 28, 2006 2:33 am    Post subject: Re: USB to Parallel adapter? Reply with quote

"Jim Thompson" <To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote in
message news:ubp3a2dme13a4lhe3dspi6k0e13a51kek1@4ax.com...
Quote:
On Wed, 28 Jun 2006 01:56:24 GMT, Joerg
notthisjoergsch@removethispacbell.net> wrote:

Hello Jim,


I would think that one of you bit-bangers could design a USB-to-LPT
device and then write software to take parallel port commands and
convert them to USB (and back). No?


I was told by a (pretty good) Windows programmer that such a task of
near realtime control via USB can quickly turn into a major nightmare.
Deadline is near, stuff don't work, coffee, more coffee, Prozac...

You have to deal with numerous intricacies of Windows, a product that
isn't exactly known for flawlessness. Plus I guess the market potential
for a bitbang capable device would be slim.

So bit-bangers aren't up to analog-level design ?:-)

Actually the USB bus is time sliced at 1ms chunks, so even the best case

would be a 2ms + pulse when bit banging. A far cry from DOS and a fast PCI
port. Thats why most attempts fail. You need smarts in the adaptor, but that
affects copmpatibility.

Cheers
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Si Ballenger
electronics forum Guru Wannabe


Joined: 02 May 2005
Posts: 121

PostPosted: Wed Jun 28, 2006 2:20 am    Post subject: Re: USB to Parallel adapter? Reply with quote

On Tue, 27 Jun 2006 17:07:34 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@My-Web-Site.com> wrote:

Quote:
I would think that one of you bit-bangers could design a USB-to-LPT
device and then write software to take parallel port commands and
convert them to USB (and back). No?

Even if you got a new laptop with a parallel port, the O-scpoe
software might not work with it. Hardware timing with XP will
probably not be as quick and acurate as with win98, and the
software may not have proper drivers to work with XP. I've got
aToshiba laptop with a parallel port, and I haven't been able to
bitbang it as of yet.
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Jim Thompson
electronics forum Guru


Joined: 06 May 2005
Posts: 5440

PostPosted: Wed Jun 28, 2006 2:12 am    Post subject: Re: USB to Parallel adapter? Reply with quote

On Wed, 28 Jun 2006 01:56:24 GMT, Joerg
<notthisjoergsch@removethispacbell.net> wrote:

Quote:
Hello Jim,


I would think that one of you bit-bangers could design a USB-to-LPT
device and then write software to take parallel port commands and
convert them to USB (and back). No?


I was told by a (pretty good) Windows programmer that such a task of
near realtime control via USB can quickly turn into a major nightmare.
Deadline is near, stuff don't work, coffee, more coffee, Prozac...

You have to deal with numerous intricacies of Windows, a product that
isn't exactly known for flawlessness. Plus I guess the market potential
for a bitbang capable device would be slim.

So bit-bangers aren't up to analog-level design ?:-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.
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