Hello all,

I've got an USB host-to-host (data) cable (the one with some hardware in the
middle). The problem is that it presents itself as ... something which
needs cable-specific drivers to be installed before it will/can work. And
ofcourse it software wants to emulate a LAN connection when given half a
chance. :-\

What I'm looking for instead is a simple USB host-to-host cable which is
recognised by the OS as a standard serial port (without needing to install
drivers). I've been googeling, DDG-ing, brave-ing and startpage-ing for a
while, but cannot seem to find such a cable.

So, my question : does someone here know of the existance of such a simple
USB host-to-host serial connection cable and has an URL for me ?

Regards,
Rudy Wieser

On 1/11/2023 11:33 AM, R.Wieser wrote:
> Hello all,
>
> I've got an USB host-to-host (data) cable (the one with some hardware in the
> middle). The problem is that it presents itself as ... something which
> needs cable-specific drivers to be installed before it will/can work. And
> ofcourse it software wants to emulate a LAN connection when given half a
> chance. :-\
>
> What I'm looking for instead is a simple USB host-to-host cable which is
> recognised by the OS as a standard serial port (without needing to install
> drivers). I've been googeling, DDG-ing, brave-ing and startpage-ing for a
> while, but cannot seem to find such a cable.
>
> So, my question : does someone here know of the existance of such a simple
> USB host-to-host serial connection cable and has an URL for me ?
>
> Regards,
> Rudy Wieser

You are describing a local-area network (LAN). Have you considered
having a router with ethernet cables to create your LAN?

--
David E. Ross
<http://www.rossde.com/>

Beyond Meat and other such vegetarian meat substitutes
represent the ultimate in ultra-processed foods. Real
meat is natural. Beyond Meat is definitely not.

"David E. Ross" <nobody@notme.invalid> wrote in message
news:tpn36m$1kab$1@gioia.aioe.org...

>> So, my question : does someone here know of the existance of such a
>> simple
>> USB host-to-host serial connection cable and has an URL for me ?
>
> You are describing a local-area network (LAN). Have you considered
> having a router with ethernet cables to create your LAN?

Than I failed to explain myself. :-)

What I *do not* want is a LAN connection (over ethernet or otherwise)
between the two machines - due to some security considerations. Just a
simple serial connection. That way its upto me to decide whats going to be
transmitted / received. Possibly using some simple serial console
software.

Regards,
Rudy Wieser

R.Wieser wrote:

> What I *do not* want is a LAN connection (over ethernet or otherwise)
> between the two machines - due to some security considerations. Just a
> simple serial connection. That way its upto me to decide whats going to be
> transmitted / received. Possibly using some simple serial console
> software.

buy two USB->serial leads, and join them with a null-modem cable (female DB9
each end with crossover)

On 2023-01-11 21:51, R.Wieser wrote:
> "David E. Ross" <nobody@notme.invalid> wrote in message
> news:tpn36m$1kab$1@gioia.aioe.org...
>
>>> So, my question : does someone here know of the existance of such a
>>> simple
>>> USB host-to-host serial connection cable and has an URL for me ?
>>
>> You are describing a local-area network (LAN). Have you considered
>> having a router with ethernet cables to create your LAN?
>
> Than I failed to explain myself. :-)
>
> What I *do not* want is a LAN connection (over ethernet or otherwise)
> between the two machines - due to some security considerations. Just a
> simple serial connection. That way its upto me to decide whats going to be
> transmitted / received. Possibly using some simple serial console
> software.

Then use two USB to RS232 converters, and connect them with a serial cable.

--
Cheers, Carlos.

Andy Burns wrote:

> buy two USB->serial leads, and join them with a null-modem cable (female DB9
> each end with crossover)

Or in a single "device" as you originally wanted, but quite expensive

<https://ftdichip.com/products/usb-nmc-2-5m/>

On Wed, 11 Jan 2023 21:51:17 +0100, R.Wieser wrote:
>
> Than I failed to explain myself. :-)
>
> What I *do not* want is a LAN connection (over ethernet or otherwise)
> between the two machines - due to some security considerations. Just a
> simple serial connection. That way its upto me to decide whats going to be
> transmitted / received. Possibly using some simple serial console
> software.
>
> Regards,
> Rudy Wieser

It's as the other two have said. You'll need two USB serial adapters (aka.
USB-to-Serial), and a serial cable. Those 3 parts.

While it's possible to have them in a single unit/product, I haven't seen
any. By far, you'll only find a hobbyist made product. If you're lucky, it
would be available for sale. But it'll likely be more expensive than just
getting those 3 parts.

And if you have soldering skill, you can make your own serial cable so that
you can decide how long the serial cable would be - which can be longer than
the maximum length of a USB cable for data transfer.

On 1/11/2023 3:51 PM, R.Wieser wrote:
> "David E. Ross" <nobody@notme.invalid> wrote in message
> news:tpn36m$1kab$1@gioia.aioe.org...
>
>>> So, my question : does someone here know of the existance of such a
>>> simple
>>> USB host-to-host serial connection cable and has an URL for me ?
>>
>> You are describing a local-area network (LAN). Have you considered
>> having a router with ethernet cables to create your LAN?
>
> Than I failed to explain myself. :-)
>
> What I *do not* want is a LAN connection (over ethernet or otherwise)
> between the two machines - due to some security considerations. Just a
> simple serial connection. That way its upto me to decide whats going to be
> transmitted / received. Possibly using some simple serial console
> software.
>
> Regards,
> Rudy Wieser
>
>

The cable you have (with the bidirectional FIFO in the middle of the cable)
is a "laplink cable". There is a USB2 version and a USB3 version. The
datarate usually does not approach the limits of USB3, by quite a stretch.

There are a couple softwares for it. Ancient, at this point in time.
One was a dual-pane interface similar to an FTP interface (it lists
two file systems, and allows copy from one to the other).

The second piece of software might be more IP-like.

*******

An alternate implementation, is to look into some FTDI devices.

Most ordinary serial comms are async and use a 16x sampling clock.
The clock is not passed from one unit to the other. On the
falling edge of data, the receiving unit counts over 8 clocks,
and samples in the middle of a bit cell. If the two clocks at
either end of the link, differ too much in frequency,
the last bit sampled, is not being sampled dead-center.

In synchronous serial, the clock is 1x and is passed between
devices. This should allow a serial connection at 16x the rate.
But 16 times nothing is still nothing, and this remains
painfully slow. We're talking twice the rate of Bluetooth.

You are unlikely to find a synchronous serial hardware item on Ebay.
It's something you might build for yourself.

Check the FTDI site for newer concepts and see what is available.

You could check out Linux and see if their implementation of
Laplink is any better. It's the layer on top which is distracting.
Nothing requires IP to make a bidirectional mailbox hardware to work.

The company making one of the USB mailbox devices, was "Prolific".
A patent was involved, and a competitor was sued in court. The
prolific.com.tw site looks like it has succumbed to misfortune,
so don't waste your time on that. Either the domain was
bought, or the company was bought and neutered.

If you sort the table here, the fastest thing that FTDI offers
is 400MB/sec (over USB3).

https://ftdichip.com/product-category/products/

https://ftdichip.com/products/umft601x-b/ # FT601

https://ftdichip.com/wp-content/uploads/2020/07/DS_FT600Q-FT601Q-IC-Datasheet.pdf # chip spec

It would be the usual amount of fun. Unfortunately.

https://www.reddit.com/r/FPGA/comments/f0tqfo/help_with_ftdi_ft601_usb3_bridge/

Paul

R.Wieser wrote:
> "David E. Ross" <nobody@notme.invalid> wrote in message
> news:tpn36m$1kab$1@gioia.aioe.org...
>
>>> So, my question : does someone here know of the existance of such a
>>> simple
>>> USB host-to-host serial connection cable and has an URL for me ?
>>
>> You are describing a local-area network (LAN). Have you considered
>> having a router with ethernet cables to create your LAN?
>
> Than I failed to explain myself. :-)
>
> What I *do not* want is a LAN connection (over ethernet or otherwise)
> between the two machines - due to some security considerations. Just a
> simple serial connection. That way its upto me to decide whats going to be
> transmitted / received. Possibly using some simple serial console
> software.

You can have a LAN using Ethernet between two machines without having
those machines connected to anything else - so no security concerns.
Unless you can explain to us why this would not be sufficiently secure
for you.

If both machines are set to "Auto" IP address, then they will use an "IP
Autoconfiguration Address" (typically 169.x.y.z) and NetBIOS name
resolution, so Windows Networking will function between the two.

--
Graham J

On 1/11/2023 5:51 PM, Graham J wrote:
> R.Wieser wrote:
>> "David E. Ross" <nobody@notme.invalid> wrote in message
>> news:tpn36m$1kab$1@gioia.aioe.org...
>>
>>>> So, my question : does someone here know of the existance of such a
>>>> simple
>>>> USB host-to-host serial connection cable and has an URL for me ?
>>>
>>> You are describing a local-area network (LAN).  Have you considered
>>> having a router with ethernet cables to create your LAN?
>>
>> Than I failed to explain myself. :-)
>>
>> What I *do not* want is a LAN connection (over ethernet or otherwise)
>> between the two machines - due to some security considerations.  Just a
>> simple serial connection.   That way its upto me to decide whats going to be
>> transmitted / received.   Possibly using some simple serial console
>> software.
>
> You can have a LAN using Ethernet between two machines without having those machines connected to anything else - so no security concerns. Unless you can explain to us why this would not be sufficiently secure for you.
>
> If both machines are set to "Auto" IP address, then they will use an "IP Autoconfiguration Address" (typically 169.x.y.z) and NetBIOS name resolution, so Windows Networking will function between the two.
>
>

He's trying to fashion "private" hardware, which is
less integrated into anything else in the machine.

He can unplug a network cable and his "private" hardware
continues to function.

Paul

On 1/11/2023 3:59 PM, Paul wrote:
> On 1/11/2023 5:51 PM, Graham J wrote:
>> R.Wieser wrote:
>>> "David E. Ross" <nobody@notme.invalid> wrote in message
>>> news:tpn36m$1kab$1@gioia.aioe.org...
>>>
>>>>> So, my question : does someone here know of the existance of such a
>>>>> simple
>>>>> USB host-to-host serial connection cable and has an URL for me ?
>>>>
>>>> You are describing a local-area network (LAN).  Have you considered
>>>> having a router with ethernet cables to create your LAN?
>>>
>>> Than I failed to explain myself. :-)
>>>
>>> What I *do not* want is a LAN connection (over ethernet or otherwise)
>>> between the two machines - due to some security considerations.  Just a
>>> simple serial connection.   That way its upto me to decide whats going to be
>>> transmitted / received.   Possibly using some simple serial console
>>> software.
>>
>> You can have a LAN using Ethernet between two machines without having those machines connected to anything else - so no security concerns. Unless you can explain to us why this would not be sufficiently secure for you.
>>
>> If both machines are set to "Auto" IP address, then they will use an "IP Autoconfiguration Address" (typically 169.x.y.z) and NetBIOS name resolution, so Windows Networking will function between the two.
>>
>>
>
> He's trying to fashion "private" hardware, which is
> less integrated into anything else in the machine.
>
> He can unplug a network cable and his "private" hardware
> continues to function.
>
> Paul
>

I have a LAN connecting my PC to my wife's PC. See my
<http://www.rossde.com/computer/LAN.html>.

We use either-net cables connecting our PCs to a common router, which is
separate from our Internet modem. All the cables are within our house.
We control who enters our house. I disabled the WiFi function of the
router. I guess I could disconnect the router from the modem; they both
sit on my computer desk. I fail to see how my LAN is not secure. Can
an ether-net cable be less secure than a USB cable?

By the way, my wife shuts down her PC if she leaves the room where it
is. If I leave the room where my PC is, I merely disable my Internet
connection, which really disables my connection to the router. If I
leave the house, I shut down my PC.

If we are away more than a day, I power-off all the equipment; and then
I power-off the surge-suppressing power strip into which they are all
plugged. My wife turns off her surge-suppressing power strip and
unplugs the microwave oven in the kitchen. There is no point in risking
damage if Southern California Edison has another hiccup (which they have
too often).

--
David E. Ross
<http://www.rossde.com/>

Beyond Meat and other such vegetarian meat substitutes
represent the ultimate in ultra-processed foods. Real
meat is natural. Beyond Meat is definitely not.

Andy, carlos,

> buy two USB->serial leads, and join them with a null-modem cable (female
> DB9 each end with crossover)

:-) Yes, I also considered that.

Alas, the RS232's baudrate would be a serious bottleneck (understatement) in
the transmission speed. AFAIK the maximum RS232 baudrate is way less than
a meg, while the USB2 "baudrate" is near to half a gig.

Regards,
Rudy Wieser

"Paul" <nospam@needed.invalid> wrote in message
news:tpnasu$11b21$1@dont-email.me...
> On 1/11/2023 3:51 PM, R.Wieser wrote:

> The cable you have (with the bidirectional FIFO in the middle of the
> cable)
> is a "laplink cable".

I've seen it being described with several different names - depending on how
much the supporting software offers.

> The datarate usually does not approach the limits of USB3, by quite a
> stretch.

:-) What I currently have can't even be described as "by quite a stretch".
Even if I would get half the USB 2 speed I would add a zero or two.

> There are a couple softwares for it. Ancient, at this point in time.
> One was a dual-pane interface similar to an FTP interface (it lists
> two file systems, and allows copy from one to the other).

As long as the connection presents itself as a serial one I'm sure I can
find or (try to) write software for it.

> An alternate implementation, is to look into some FTDI devices.

Thats the first thing I did. Alas, I only found such devices that limited
itself to the RS232 speeds (with a max baudrate way below a single meg).

> If you sort the table here, the fastest thing that FTDI offers
> is 400MB/sec (over USB3).
....
> https://ftdichip.com/products/umft601x-b/ # FT601

The speed specs look good. The price ? Not so much - especially when I need
two to create a connection (as well as a power supply to feed them).

However, the biggest drawback would be that it can't be used as a simple
serial connection - it would (again) need a special driver / software to get
those parallel pins to toggle just right ...

Thanks for the suggestion though.

Regards,
Rudy Wieser

"Graham J" <nobody@nowhere.co.uk> wrote in message
news:tpneio$11ndt$1@dont-email.me...
> R.Wieser wrote:

>> What I *do not* want is a LAN connection (over ethernet or otherwise)
>> between the two machines - due to some security considerations.
>
> You can have a LAN using Ethernet between two machines without having
> those machines connected to anything else - so no security concerns.

:-) What about protecting both machines *from each other* ? Doesn't
that count ? To me it does.

> Unless you can explain to us why this would not be sufficiently secure for
> you.

I did not think I would need to (it feels like explaining that water is
wet). But alas, you have proven me wrong. :-|

Regards,
Rudy Wieser

"Paul" <nospam@needed.invalid> wrote in message
news:tpnig3$124d0$1@dont-email.me...
> On 1/11/2023 5:51 PM, Graham J wrote:

> He's trying to fashion "private" hardware, which is
> less integrated into anything else in the machine.

Pretty much that, yes.

There are just too many Windows services running which (try to) connect to
the LAN (a nice program, wireshark). And even if I could find them all (I
tried, I can't) there are a number which can't be switched off, as they also
service the local machine and thus doing so will cause "a degraded
performance".

> He can unplug a network cable and his "private" hardware
> continues to function.

Currently only one of the (currently thought about) machines has its
ethernet cable plugged in, the other not. But even if they would both be
they would not be able to reach each other, as they are on different LANs .

Regards,
Rudy Wieser

"David E. Ross" <nobody@notme.invalid> wrote in message
news:tpnnj9$1dc4$1@gioia.aioe.org...

> I fail to see how my LAN is not secure.

That depends on how you look at it. Your LAN - with all of its computers
attached to it - might be secure from the big, bad world "out there", but
computers in it are not secure from each other.

> Can an ether-net cable be less secure than a USB cable?

Not can, *is*.

An ethernet cable is a super highway, allowing for all kinds of trafic. If
you install a packet-capture program (pcap, wireshark) you will see that you
puters communicate with each other even when none or your family is sitting
behind one. Courtesy of multiple Windows Services.

An USB cable as I am asking for(1) only offers a single channel, and Windows
doesn't try to do anything with it itself. IOW, no data will go over it
/unless/ I specifically ask for it - for which *I* have to start an
application *on both sides* (one host, one client).

(1) Yes, an USB slot in your 'puter (where you plug a cable, thumbdrive or
similar into) isn't much better than an ethernet cable security wise : The
plugged-in USB device tells the puter what it is (can be multiple things at
the same time), and as such you can plug in something which /looks/ like a
thumbdrive, but tells your computer its also another keyboard. Just a few
simulated keystrokes further and it downloads malware from a hidden storage
on the same stick to your 'puter and you're f*cked ...

Regards,
Rudy Wieser

R.Wieser wrote:
> "Graham J" <nobody@nowhere.co.uk> wrote in message
> news:tpneio$11ndt$1@dont-email.me...
>> R.Wieser wrote:
>
>>> What I *do not* want is a LAN connection (over ethernet or otherwise)
>>> between the two machines - due to some security considerations.
>>
>> You can have a LAN using Ethernet between two machines without having
>> those machines connected to anything else - so no security concerns.
>
> :-) What about protecting both machines *from each other* ? Doesn't
> that count ? To me it does.
>
>> Unless you can explain to us why this would not be sufficiently secure for
>> you.
>
> I did not think I would need to (it feels like explaining that water is
> wet). But alas, you have proven me wrong. :-|

Anythng that connects one computer to another has the potential to
transfer malware. Floppy disk, USB memory, USB cable ...

You need to evaluate the risk.

What sort of data do you want to transfer between the two machines?

--
Graham J

"Graham J" <nobody@nowhere.co.uk> wrote in message
news:tpoiia$17sl2$1@dont-email.me...

> Anythng that connects one computer to another has the potential to
> transfer malware. Floppy disk, USB memory, USB cable ...

True.

> You need to evaluate the risk.

Also true.

Alas, you only took one, your own situation for consideration, which doesn't
result in any kind of usefull evaluation.

> What sort of data do you want to transfer between the two machines?

What problem(s) are you thinking of ?

Regards,
Rudy Wieser

R.Wieser wrote:
> "Graham J" <nobody@nowhere.co.uk> wrote in message
> news:tpoiia$17sl2$1@dont-email.me...
>
>> Anythng that connects one computer to another has the potential to
>> transfer malware. Floppy disk, USB memory, USB cable ...
>
> True.
>
>> You need to evaluate the risk.
>
> Also true.
>
> Alas, you only took one, your own situation for consideration, which doesn't
> result in any kind of usefull evaluation.
>
>> What sort of data do you want to transfer between the two machines?
>
> What problem(s) are you thinking of ?

Two examples:

- Simple text such as phone numbers

- Complex documents (such as a book) where both users need to review and
edit the material.

In the first case, a handwritten note would suffice.

In the second case your decision is really whether you use a computer or
not. If you do, then the file sharing built into the OS would be pretty
well essential. If not then use a typewriter and lots of pieces of
paper - as was done 50 years ago.

--
Graham J

Andy Burns wrote:
> R.Wieser wrote:
>
>> What I *do not* want is a LAN connection (over ethernet or otherwise)
>> between the two machines - due to some security considerations. Just a
>> simple serial connection. That way its upto me to decide whats going to be
>> transmitted / received. Possibly using some simple serial console
>> software.
>
> buy two USB->serial leads, and join them with a null-modem cable (female DB9
> each end with crossover)

I'd use a more trivial approach: use a USB stick. These days they
cost almost nothing, and the largest -and of course most expensive-
I've come across has a 1 TB capacity.

-p

"Graham J" <nobody@nowhere.co.uk> wrote in message
news:tpoo6k$18f2o$1@dont-email.me...
> R.Wieser wrote:

>>> What sort of data do you want to transfer between the two machines?
>>
>> What problem(s) are you thinking of ?
>
> Two examples:
>
> - Simple text such as phone numbers
>
> - Complex documents (such as a book) where both users need to review and
> edit the material.

The transfer method - being ethernet, serial, floppy, thumbdrive or even
avian carrier - does not distingush between those two - or any other kind
for that matter.

How the transferred data is presented to the user is his own choice.

Regards,
Rudy Wieser

"Piet" <www.godfatherof.nl/@opt-in.invalid> wrote in message
news:tpov7k$14gq$1@gioia.aioe.org...

> I'd use a more trivial approach: use a USB stick.

Yeah .... thats what I currently use and want to move away from. <whistle>

Regards,
Rudy Wieser

On 12.01.2023 13:50, R.Wieser wrote:
> "Piet" <www.godfatherof.nl/@opt-in.invalid> wrote in message
> news:tpov7k$14gq$1@gioia.aioe.org...
>
>> I'd use a more trivial approach: use a USB stick.
>
> Yeah .... thats what I currently use and want to move away from. <whistle>

Then why not use an USB switch like:

https://www.amazon.de//dp/B09Z6GV4G3/

This way you don't have to manually remove the stick but
just press a button.

On Thu, 12 Jan 2023 13:50:06 +0100, "R.Wieser" <address@not.available>
wrote:

>
>"Piet" <www.godfatherof.nl/@opt-in.invalid> wrote in message
>news:tpov7k$14gq$1@gioia.aioe.org...
>
>> I'd use a more trivial approach: use a USB stick.
>
>Yeah .... thats what I currently use and want to move away from. <whistle>

Given that this is some kind of a cross between "I've Got a Secret" and
"20 Questions", I'll offer the solution that I would use. Note that you
haven't said much about your requirements, nor your concerns, so I'm
filling in the gaps here.

I would use Ethernet, 100%. Nothing else comes close. Use an
intermediary device*, such as a pfSense firewall, which is free and can
block 100% of the traffic. Then, allow only port 22 (or the random port
of your choice) and use SSH. I don't think any Windows services use SSH
to probe the network, do they?

Obviously, the Ethernet connections would use a subnet other than the
one used for your LAN, even if they use the same NICs. You can add as
many different IPs/subnets to a NIC as you like, giving you OSI Layer 3
separation from your regular LAN.

*I would use an F5 LTM (Local Trafic Manager), because I have access to
as many of those [virtual] devices as I need. They aren't free, though.
I have access via my work. That's why I suggest the free pfSense.

On 1/11/23 13:37, David E. Ross wrote:

[snip]

> You are describing a local-area network (LAN). Have you considered
> having a router with ethernet cables to create your LAN?

A router is used to connect multiple networks (such as connecting your
own network to the internet). There's no need for a router just to
connect 2 computers (more than 2 wound require a switch, but not a router).

--
Mark Lloyd
http://notstupid.us/

"I don't want to see any religious people in public office because
they're working for another boss." [Frank Zappa]