Another serial solution? "rs232-serial-wifi-modem-for-vintage-computers-v3"

[Heinz-Bernd Eggenstein]

I didn't want to hijack any of the existing threads for this...has anyone here tried the "RS232 Serial Wifi Modem for Vintage Computers" ?

https://www.tindie.com/products/theoldnet/rs232-serial-wifi-modem-for-vintage-computers-v3/

The beauty of this thingy is supposed to be that it plugs into physical R232 connectors and then, from the point of view of the equipment, looks like a phone line modem and can be  driven by AT command just like you would expect. But instead of telephone numbers for dialing, you provide an IP address, and the established connection will run over a  WiFi TCP/IP connection to the "dialed" IP address (which could be local or WAN).

The thingy can apparanetly also optionally simulate receiving calls by listening for incoming TCP/IP connections and then simulate  that the modem answers the call (not sure how it would handle mutiple simultaneous call attempts tho..).

On paper this looks nice IMHO, if it works as promised. I wonder whether this could be used to re-create a more  "true to the original" version of UUCP and similar stuff currently discussed here, with less need for behind the scene "cheating" on the PiDP-11(8)'s Raspi host.

Cheers
HBE

 

[Owen Morgan]

I've built them and use one on my AltairDuino ... they work really well and are great for demonstrating telnet BBS systems

I've not used one to receive calls yet but this will be part of my next project. We're fortunate that the PDP11 can now support TCP/IP stacks and can reply to telnet requests! :-)

[anton.la...@gmail.com]

I was impressed by this little thing's description, so I ordered one, hoping to plug it in my real old VT330 and make it "wireless"....  That'd be so cool, right?

LOL that did not quite work from the get-go, unfortunately.  The thing is, even though the software flow control is "configurable" in that modem,

there's no actual implementation!  (Yeah, it's just plain empty!  There's even a bug report w.r.t. the issue, see #22 on github.)

So, when you Hold/Release the output, it does get garbled due to buffer overruns.

HW flow control is not properly implemented because there are not enough pins on the processor chip (DEC terminals expect to have 5 control

lines, and seem to be using all of them -- VT330 has an option to use a subset, but the modem seems to only implement the CTS/RTS handshake,

which is not enough).

So, while plugging it into a PC (where the terminal software in front of the serial port is unlikely to run into any buffering issues) will probably

be problem-free (but honestly, I haven't tried), this little thing cannot be used with the real old hardware, whose buffering area for the serial

connection is quite limited.  That is, not until at least XOFF/XON is implemented -- it does not seem to be big a deal, not sure why it hasn't been done yet.

Otherwise, it's a very nicely built thing and a great idea, actually!

[Michael Katzmann]

.. and it doesn't do 110 Bd 🙀

--
You received this message because you are subscribed to the Google Groups "[PiDP-11]" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pidp-11+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/pidp-11/1a6331d1-5ccd-4c05-89d2-f050685367b9n%40googlegroups.com.

--

   |\      _,,,---,,_             Michael Katzmann
   /,`.-'`'    -.  ;-;;,_         NV3Z / VK2BEA / G4NYV
  |,4-  ) )-,_. ,\ (  `'-'
 '---''(_/--'  `-'\_)

[timr...@gmail.com]

I bought one of these for use with my old DOS PC.  He's now offered an upgrade that this can be flashed with new firmware to provide a wireless Internet

connection.  I can not get it to flash no matter what I try.  His zip package includes a Windows utility called esphomeflash (or something like that).  I have one

Windows PC for gaming that runs Win10.  Running that tool can't get access to the Com port.  Even running the DOS environment as Admin does not work.

Moved over to Linux and had some progress but it won't flash.  Don't know if it requires and older PC that has a real serial port (this is my guess).  I only

have USB ports and use a USB to serial cable. These have worked to connect old terminals to my Mac.  So I figured it should work for this.  Nope.  So have

finally just given up trying to flash and will find myself an old 3C509 board.

[Anton Lavrentiev]

I suppose for flashing you need to connect that board to PC using the USB cable (not via the COM port)...  Also, for the USB device to be recognized by Windows you need to install an additional Windows driver.... The link is in the "manual".... I haven't tried it myself yet, but from your response I got an impression that that's not what you were doing. Sorry if I misread...

You received this message because you are subscribed to a topic in the Google Groups "[PiDP-11]" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/pidp-11/iCO2ovleIsg/unsubscribe.
To unsubscribe from this group and all its topics, send an email to pidp-11+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/pidp-11/df1a5a6e-11c0-455c-94fc-4858006610bcn%40googlegroups.com.

[anton.la...@gmail.com]

And just a follow-up, I was able to connect the board to my PC via USB:  at first the device was recognized as a COM port but failed to find a driver.  So, I just used Google search for "CP210x UART driver" and downloaded the driver from the Silabs website directly (the link in the manual "mentioned" earlier seems outdated).  There is a universal driver for Win11/10, and also an older driver for Win7 (no need for a enumeration version with this device, BTW).  Once installed, I was able to use my favorite terminal app (PuTTY), open the modem on COM5, make it connect to PiDP11 over my home WiFi, login into my system, and it worked perfectly fine (well, except for the XOFF/XON issue)...  I haven't tried re-flashing (no need this far yet), but since the port is recognized, I don't think it's going to be a problem.  It definitely does not need any older PC with the USB side of business :-)

[Tim Radde]

Tried that, and no USB port is shown if I connect via the micro-USB port.  I still would expect Windows to allow Com port access.  It shows as working.

I never found another driver for it.  Maybe there is some mention in there.  He says he only provides directions for Windows but states it should be

flashable on Linux or Mac.  I am not the only one having this issue.

To view this discussion on the web visit https://groups.google.com/d/msgid/pidp-11/9dd9e580-5275-4050-af5b-061e61513d10n%40googlegroups.com.

[Tim Radde]

Now that I see this driver I believe I did try to install it and Windows claimed I already had the best driver installed so did not allow it.

I will try again.

[timr...@gmail.com]

Tried it again.  With only USB plug connected it does not show a Com port.  With DB9 end connected it does.  I installed that special driver and Windows says it

installed.  But to what I do not know.  Didn't help.  Still no access to Com port even though it shows.  I ran Port Monitor and nothing is open when I try this.  

I give up for now.

[Anton Lavrentiev]

Sorry about that.... I am just curious what Windows Device Manager shows about this board in your case?

To view this discussion on the web visit https://groups.google.com/d/msgid/pidp-11/96cf97a4-05ff-4e0a-b654-40de90f55a13n%40googlegroups.com.

[Tim Radde]

Windows reports it on Com3 when I plug in a USB cable to the DB9 end.  I believe the first time I tried this it was on Com4 that no long shows.

I unhid all Com ports and several then show such as Com4 but it's not in use but was at one time.  Also shows and XBox controller port

that I had tried at one time.  The serial control port does have the VCP box checked.  It's just that it does not work.  The only USB to Serial cable

I have is a: Valley Enterprises USB to RS232 Serial DB9 Cable Adapter FTDI Chipset. I can see it's lights blink when it is trying to flash.  I am

guessing the output is not reaching the card in question.  I do not know what else to do for this.  I have tried everything I can think of and

am usually good at solving these types of problems as I worked with computers for decades and I know the odd things that can go wrong.

[Anton Lavrentiev]

The modem's chipset is by Silicon Labs, CP210x; not FTDI, so the one,
which you are seeing, is not it.

I don't understand, though, why your Windows starts showing the wifi
modem once you plug it -- because plugging it with the DB9 end does
not add a COM port
to your machine -- it's already there, it just connects a device on
the other end (also, it does not use any USB UART chipsets in this
case as none needed).
So the port should have been shown as available all along -- it's your
PC's port, whether something's plugged into it, or not.

Windows has a feature of COM port reservations... Meaning every time
you plug a COM-port compatible USB device, it will create a COM port
for it.
With an increasing number. Even if you plug the same thing into a
different USB port, it'd be the next port number... And some apps do
not
want to show more than 4 COM ports (just because it's what used to be
the maximum)... There's a very useful tool, ComNameArbiter available
from
here: www.uwe-sieber.de ... It can help you remove those extra
reservations. Make sure to run it as administrator. Then leave the
checkmarks only
next to the COM ports you want to keep, and clear all other by
clicking the two buttons up top ("Clear unused reservations" and
"Remove non-present devices").
Don't worry, the drivers you've installed (if any, in addition) will
not be removed, so next time you plug the COM port device into USB,
the driver is
going to be loaded, and the next available COM port assigned. Maybe
this will help you with the issue you're having (I know you said you'd
given up,
but still). Good luck!

[Heinz-Bernd Eggenstein]

Since you mentioned your FTDI cable adapter, I suspect that there is a bit of a misunderstanding here. When you are asked to connect the thingy via USB to your computer for the firmware update, it is NOT meant to go thingy->RS232->Adapter->USB->PC , but just to connect thingy->micro-USB-->USB cable->PC., so using the port that is otherwise used for power. The PC will power the thingy and communicate with it over this port.

According to http://theoldnet.com/TheOldNet%20Wifi%20Modem%20Manual.pdf there are different versions out there, one has a jumper that is used in the update procedure, but the one I got just today has a pushbutton labelled "Flash" ... hint, hint...

Does that help?

HB

[timr...@gmail.com]

Yes, this helped.  I stole (borrowed) a different micro USB cable from my 3d printer.  Upon plug in Windows showed that on Com4 as a CP210x.  It then flashed.

So it's obvious the cable I had used before it defective.  Thanks for continuing to press me to keep trying.  Now I can see if DOS can actually see it.  Thanks again.

[timr...@gmail.com]

Flashed again just in case.  It goes thru all the output of flashing and reports done.  Still shows 1 error in the view logs.  Don't know if this is a red herring or not.

Tried connecting to set the baud rate lower than 115200 as I believe my older PC may not be able to support that fast.  Can't talk to it.  On Windows tried Putty and

TeraTerm.  Nothing.  On Linux tried Putty and the SLIP suggestion of using slattach and setting a point to point.  Neither let me connect. So now I don't know if

it did not flash or something else.  This is really getting to be annoying.

[Anton Lavrentiev]

Hmm.... By default it's 300 baud, unless you're flashing something which has it higher...  Try resetting it by keeping the reset button for 5 sec while powering it up .... Then set teraterm/putty to 300 baud and hopefully you'll be able to connect and re-program the modem to a higher speed

To view this discussion on the web visit https://groups.google.com/d/msgid/pidp-11/b55ef353-d647-4e43-8568-642df30fc676n%40googlegroups.com.

[timr...@gmail.com]

According to the creator of this stuff the modem default is 300, where the ethernet SLIP part defaults to 115200.  I have tried several different values.

115200, 57600, 300.  Nothing works.  Leads me to think the flash did not complete properly, even though it reported it did.  I do see the little blue led

blinking during flashing so it's doing something.  Just have no way to access now.  Thanks.

[Anton Lavrentiev]

You can try asking they guy... I corresponded with him lately, he seems to be quite responsive.... Sorry about your troubles, though 

To view this discussion on the web visit https://groups.google.com/d/msgid/pidp-11/edd29a0f-bbc2-4de0-b082-2e6afbd44fb0n%40googlegroups.com.

[Tim Radde]

I am going to try flashing back to the modem to see if that gives any response.  I flashed this on Linux and got no errors, but still

do not get any response at all different baud rates and with and without a null modem.  I am sure there is just some simple

step I am missing.

[Tim Radde]

Should the blue LED be on when the device is plugged in and flashed?  It blinks once and does not stay on.

This is for the modem flash.  I think I remember seeing it on before though.  The modem flash still does not

work for me either.

[Tim Radde]

Some progress.  I decided to try the other USB serial cable I have.  I had left the device with the modem flash in it.  This 

worked and displayed the menu.  So I reflashed the other image for SLIP Ethernet and no go.  It displays garbage.  Tried

all different baud rates.  I think part of the problem may have been my use of the 3d printer cable that I had had to cover

the power port as to not cause issue on the 3d printer screen.  If left as normal it would try to power up the 3d printer

screen which it should not and can cause damage.  So I had taped over the power pin.  Forgot I had done that.  So

when I was flashing was I really flashing?  I can't see how but I do seem to remember seeing the light blink but

that may have been with the other cable.  Maybe I should try reflashing again to see what happens.

[Tim Radde]

Well dang if I did not get it to work.  Putty would not work, Minicom would not work.  But set up the SLIP

port using "slattach" and was able to telnet in and set it up.  And moved it to my DOS box and I almost

died when I was able to ping things.  Thanks for all the suggestions.

[timr...@gmail.com]

Spoke too soon.  I can ping anything and it says it ping'd it.  I knew this as my NAS is down right now and yet it said it was

pingable.  I also can't telnet to 192.168.240.1 on port 7777 on the DOS box, but can on the Linux box.  I even reduced the

baud rate to 57600 thinking this was the issue.  Then again I am not sure of a speed it can support.  It's a 133Mhz Pentium

so would think it should be capable of 57600.  I suppose I could drop down to 9600.  It's weird that Ping says it worked 

though.  It used to time out before.  I have nothing I can FTP to at least not running as I don't use it.  Would be nice

to try something else to see if it's even getting out of the box which I doubt.