Were you ever able to get this to work? I have been at this for days / weeks now with no success using epppd. I am able to use this same method to make connection using trumpet and windows though.

I am following this guide https://medium.com/swlh/connecting-a-286-dos- … 19-b93a422ff094, but something doesn't seem right.

Did you check the logs on your *nix system? Any entries from pppd? What do they say? Do you have debug as one of pppd's parameters?

GulchWinder3D wrote on 2022-06-23, 19:41:

Did you check the logs on your *nix system? Any entries from pppd? What do they say? Do you have debug as one of pppd's parameters?

Seconded.

I also note the OP's command doesn't have "noauth" nor any options for flow control (crtscts or xonxoff).

Linux

1 
2# enable routing
3modprobe ppp_deflate
4modprobe nf_conntrack_ftp
5sysctl -w net.ipv4.ip_forward=1
6iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
7# start pppd 
8pppd -detach crtscts lock proxyarp noauth 10.0.0.1:10.0.0.2 /dev/ttyUSB0 115200 &

DOS

1 epppd.exe com2 115200 local

(Packet Handler at 0x60)

Client Config : (Mtcp for example)
IPADDR 10.0.0.2
NETMASK 255.255.255.0
GATEWAY 10.0.0.1
NAMESERVER 8.8.8.8

Or load winpkt.com for winsocks 1.1 under dos.
Then you can go online with winsocks 1.1 under Windows 3.x
Works even on 286 with old opera browser

Also worth mentioning that a parallel ("LapLink") cable is much faster than serial. DigiKey has the cables under part number AK250-3.

I should have left a little more details.

This is a variant of what I have been trying, but I have done several dozen different combinations by now.

1pppd ttyS0 115200 local lock passive silent proxyarp defaultroute noauth mtu 576 -detach debug 192.168.0.30:192.168.0.31 netmask 255.255.255.0

For some strange reason it connected once within 100 tries but I was never able to recreate or do much with it. I have tried on raspberry pi and virtual machine with same results. I am able to do this connection with ao486 in MiSTer, so I even tried using the MiSTer linux ppp in with the same settings and it still will not work. I have also tried two other PL2303 devices and all results are the same.

1 using channel 11
2Using interface ppp0
3Connect: ppp0 <--> /dev/ttyS0
4rcvd [LCP ConfReq id=0x1 <mru 1500> <magic 0xce51779> <pcomp> <accomp>]
5sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7c2c328f> <pcomp> <accomp>]
6sent [LCP ConfAck id=0x1 <mru 1500> <magic 0xce51779> <pcomp> <accomp>]
7sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x7c2c328f> <pcomp> <accomp>]
8rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x7c2c328f> <pcomp> <accomp>]
9sent [LCP EchoReq id=0x0 magic=0x7c2c328f]
10sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
11sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]
12sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
13sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]
14sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
15sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]
16sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
17sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]
18sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
19sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]
20sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
21sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]
22sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
23sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]
24sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
25sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]

It seems to be having difficulties connecting to IPCP, but I can't figure out why. I have tried different mtu, mru, and baud rates and all end up the same as well. I think it has something to do with the broadcasting in IPCP initiation but I am not really sure where to fix it.

matze79 wrote on 2022-06-23, 21:41:

Linux […]
Show full quote

Linux

Copy code to clipboard

1 
2# enable routing
3modprobe ppp_deflate
4modprobe nf_conntrack_ftp
5sysctl -w net.ipv4.ip_forward=1
6iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
7# start pppd 
8pppd -detach crtscts lock proxyarp noauth 10.0.0.1:10.0.0.2 /dev/ttyUSB0 115200 &

DOS

Copy code to clipboard

1 epppd.exe com2 115200 local

(Packet Handler at 0x60)

Client Config : (Mtcp for example)
IPADDR 10.0.0.2
NETMASK 255.255.255.0
GATEWAY 10.0.0.1
NAMESERVER 8.8.8.8

Or load winpkt.com for winsocks 1.1 under dos.
Then you can go online with winsocks 1.1 under Windows 3.x
Works even on 286 with old opera browser

Thank you I will check this out and let you know if it works

jakethompson1 wrote on 2022-06-23, 21:56:

Also worth mentioning that a parallel ("LapLink") cable is much faster than serial. DigiKey has the cables under part number AK250-3.

Interesting, I think I remember knowing this back in the day and remember using parallel to link all my computers. Would this be compatible with epppd as well?

This is mostly experimental at the moment, though the main use would be to connect laptops to the network for etherdfs / ftp, and also for kali / dali multiplayer connection support. My desktops have 3com cards with working packet drivers, but I also like the idea of having network support via serial.

Also part of what inspired this is the usb4vc. Since I have a pi in use for this purpose, I thought I would add network / data storage while I was at it.

Delphius wrote on 2022-06-23, 22:55:

Interesting, I think I remember knowing this back in the day and remember using parallel to link all my computers. Would this be […]
Show full quote

jakethompson1 wrote on 2022-06-23, 21:56:

Also worth mentioning that a parallel ("LapLink") cable is much faster than serial. DigiKey has the cables under part number AK250-3.

Interesting, I think I remember knowing this back in the day and remember using parallel to link all my computers. Would this be compatible with epppd as well?

This is mostly experimental at the moment, though the main use would be to connect laptops to the network for etherdfs / ftp, and also for kali / dali multiplayer connection support. My desktops have 3com cards with working packet drivers, but I also like the idea of having network support via serial.

Also part of what inspired this is the usb4vc. Since I have a pi in use for this purpose, I thought I would add network / data storage while I was at it.

Don't know about epppd, but PLIP is how you would connect via a DOS packet driver to a Linux/BSD machine over a parallel cable.
For Win9x, there is Direct Cable Connection built in which does use PPP... there is no driver for the Linux side of a parallel connection with it, but I'm working on one.

jakethompson1 wrote on 2022-06-23, 23:06:

Delphius wrote on 2022-06-23, 22:55:

Interesting, I think I remember knowing this back in the day and remember using parallel to link all my computers. Would this be […]
Show full quote

jakethompson1 wrote on 2022-06-23, 21:56:

Also worth mentioning that a parallel ("LapLink") cable is much faster than serial. DigiKey has the cables under part number AK250-3.

Interesting, I think I remember knowing this back in the day and remember using parallel to link all my computers. Would this be compatible with epppd as well?

This is mostly experimental at the moment, though the main use would be to connect laptops to the network for etherdfs / ftp, and also for kali / dali multiplayer connection support. My desktops have 3com cards with working packet drivers, but I also like the idea of having network support via serial.

Also part of what inspired this is the usb4vc. Since I have a pi in use for this purpose, I thought I would add network / data storage while I was at it.

Don't know about epppd, but PLIP is how you would connect via a DOS packet driver to a Linux/BSD machine over a parallel cable.
For Win9x, there is Direct Cable Connection built in which does use PPP... there is no driver for the Linux side of a parallel connection with it, but I'm working on one.

Ok good to know about PLIP, I will look into that as an option as well. Thanks for the info.

A Linux driver for Win9x Direct parallel connection would be really cool. Do you have a project page for this?

Delphius wrote on 2022-06-23, 23:16:

Ok good to know about PLIP, I will look into that as an option as well. Thanks for the info.

A Linux driver for Win9x Direct parallel connection would be really cool. Do you have a project page for this?

PLIP is also easier. You just ifconfig on the linux side, no background daemon required.

It isn't anywhere near use for testing. Interestingly, one of the biggest issues I'm running into is that the Linux machine has to pace itself in sending data to the Win9x one, by introducing deliberate delays, or otherwise the Win9x one gets overwhelmed and unresponsive to mouse/keyboard.

jakethompson1 wrote on 2022-06-23, 23:19:

Delphius wrote on 2022-06-23, 23:16:

Ok good to know about PLIP, I will look into that as an option as well. Thanks for the info.

A Linux driver for Win9x Direct parallel connection would be really cool. Do you have a project page for this?

PLIP is also easier. You just ifconfig on the linux side, no background daemon required.

It isn't anywhere near use for testing. Interestingly, one of the biggest issues I'm running into is that the Linux machine has to pace itself in sending data to the Win9x one, by introducing deliberate delays, or otherwise the Win9x one gets overwhelmed and unresponsive to mouse/keyboard.

Yah that is interesting. Are you reverse engineering or is source code for Direct Parallel Connection available?

Delphius wrote on 2022-06-23, 23:34:

Yah that is interesting. Are you reverse engineering or is source code for Direct Parallel Connection available?

There is no source. Everything was developed for MS by Parallel Technologies. I believe support was dropped in Vista. The passive "LapLink" aka "nibble mode" parallel cables, as also used by PLIP, transfer only 4 bits at a time (by abusing the status lines as inputs) and are CPU intensive. They also had a Universal FAST cable (http://web.archive.org/web/20040211074958/htt … hefastcable.htm) though I've never seen one or seen one for sale. It looks like instead of a passive cable it has a box in the middle to speak ECP/EPP directly to each system with a buffer in the middle. In theory one of the gifted hardware oriented forum posters could also design such a middle-box with USB on one end. Parallel cables also avoid the 8250/16450 serial issue, though I've never tried to use one on anything slower than a 486 anyway.

I've also never dug into whether USB-to-parallel cables would work, or if they strictly expose a USB printer interface to the host. PCIe parallel cards, in theory, could work.

I haven't done this in ages so when I saw thread I figured it was a good time to verify that it still works.

The guide at medium.com used my original mTCP instructions. Since that time the only change is probably the noauth option, which you figured out. I also had to set nocrtscts on my Linux to disable hardware flow control. (I've been through a few hardware changes there over the years.)

For reference I'm using Ubuntu 20.04, a USB to serial adapter on ttyUSB0, and a 386-40 machine.

mbbrutman wrote on 2022-06-24, 01:35:

I haven't done this in ages so when I saw thread I figured it was a good time to verify that it still works.

The guide at medium.com used my original mTCP instructions. Since that time the only change is probably the noauth option, which you figured out. I also had to set nocrtscts on my Linux to disable hardware flow control. (I've been through a few hardware changes there over the years.)

For reference I'm using Ubuntu 20.04, a USB to serial adapter on ttyUSB0, and a 386-40 machine.

Thanks for chiming in.

I just tried a similar config with nocrtscts, and still no luck. My vb is running ubuntu 18.04 and my raspberry pi 3b+ is running the newest version of raspberry os. I have tried two different vintage machines, both of them being socket 7 so maybe related. One is an AN430TX chipset with 233mmx, and the other is my HP Omnibook 800CT. Both seem to do the same thing when using epppd. What is strange is I didn't seem to have any issues using the trumpet socket either. Maybe I will try disabling some cache or something to see if that helps. I also have a 486-75 dx laptop that I could try it on just to see if there is a hardware difference. I will also note that I have tested the serial ports between the an430tx and omnibook in dos via doom / duke3d so I know it works as well.

At first I started to wonder if it was a bunk PL2303 as I hear there are many fakes. So I decided to try and rule out any issues and pick up a gearmo 4 channel FTDI. All of them seem to do the same thing so far, so I imagine all of them are actually good to use. Here are links to the ones I have tried so far.

https://www.amazon.com/dp/B0769FY7R7?ref=ppx_ … ct_details&th=1
https://www.amazon.com/dp/B0769GD9F9?ref=ppx_ … ct_details&th=1
https://www.amazon.com/dp/B004ETDC8K?psc=1&re … product_details

Sadly, some of these have got to be returned. But unfortunately nothing is working. The gearmo is probably overkill, but I will probably keep it if it works. Seems interesting to play around with 4 different ppp connections over serial.

Delphius wrote on 2022-06-24, 01:58:

I just tried a similar config with nocrtscts, and still no luck. My vb is running ubuntu 18.04 and my raspberry pi 3b+ is running the newest version of raspberry os. I have tried two different vintage machines, both of them being socket 7 so maybe related. One is an AN430TX chipset with 233mmx, and the other is my HP Omnibook 800CT. Both seem to do the same thing when using epppd. What is strange is I didn't seem to have any issues using the trumpet socket either. Maybe I will try disabling some cache or something to see if that helps. I also have a 486-75 dx laptop that I could try it on just to see if there is a hardware difference. I will also note that I have tested the serial ports between the an430tx and omnibook in dos via doom / duke3d so I know it works as well.

You got me to dig out my serial/parallel cables and do a test. It's no comparison. If you can find a "bridge" machine with a real parallel port as I have, I doubt you want to keep messing with serial...

I'm using a Panasonic Toughbook CF-51 on the Linux side and a Cyrix 486DX2/80 on the DOS side.

Parallel
Linux side:

1modprobe -r lp
2modprobe plip
3ifconfig plip0 inet 172.16.0.1 pointopoint 172.16.0.2 netmask 255.255.255.0 up
4ifconfig plip0 arp

DOS side:

1plip 0x60 7 0x378

FTP transfer with mTCP ftp client, speed: 2532352 bytes in 64.295 seconds (38.477 KBytes/sec)

Serial
Linux side: pppd /dev/ttyS0 172.16.0.1:172.16.0.2 crtscts noauth -detach debug
DOS side: epppd com2 115200 crtscts

FTP transfer with mTCP ftp client, speed: mTCP ftp client, 2532352 bytes in 253.715 seconds (9.765 KBytes/sec)

Parallel is even faster on my 386DX-40, probably fewer memory/cache wait states. And that machine has an 8250 serial and it was so frustratingly slow I gave up trying.

adalbert wrote on 2017-01-31, 16:08:

and I always get this response: PPP link is down, driver not installed.

Actually, I think you might be running into the MSR issue I described above.

Disabled system cache on my AN430TX and what do you know? It works first try.

Still going to test it some more, and make sure everything actually routes correctly. But everything seems to be happy now. I am wondering if there is a work around for this, as it would be nice not to have to keep the cache disabled.

1pppd ttyUSB0 115200 local lock passive silent proxyarp defaultroute noauth mtu 576 -detach debug 192.168.0.30:192.168.0.31 netmask 255.255.255.0 nocrtscts
2using channel 7
3Using interface ppp0
4Connect: ppp0 <--> /dev/ttyUSB0
5rcvd [LCP ConfReq id=0x1 <mru 1500> <magic 0x22256262> <pcomp> <accomp>]
6sent [LCP ConfReq id=0x1 <asyncmap 0x0> <magic 0x2b940f8f> <pcomp> <accomp>]
7sent [LCP ConfAck id=0x1 <mru 1500> <magic 0x22256262> <pcomp> <accomp>]
8rcvd [LCP ConfAck id=0x1 <asyncmap 0x0> <magic 0x2b940f8f> <pcomp> <accomp>]
9sent [LCP EchoReq id=0x0 magic=0x2b940f8f]
10sent [CCP ConfReq id=0x1 <deflate 15> <deflate(old#) 15> <bsd v1 15>]
11sent [IPCP ConfReq id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]
12rcvd [IPCP ConfReq id=0x1 <addr 0.0.0.0> <compress VJ 0f 01>]
13sent [IPCP ConfNak id=0x1 <addr 192.168.0.31>]
14rcvd [LCP EchoRep id=0x0 magic=0x22256262]
15rcvd [LCP ProtRej id=0x2 80 fd 01 01 00 0f 1a 04 78 00 18 04 78 00 15 03 2f]
16Protocol-Reject for 'Compression Control Protocol' (0x80fd) received
17rcvd [IPCP ConfAck id=0x1 <compress VJ 0f 01> <addr 192.168.0.30>]
18rcvd [IPCP ConfReq id=0x2 <addr 192.168.0.31> <compress VJ 0f 01>]
19sent [IPCP ConfAck id=0x2 <addr 192.168.0.31> <compress VJ 0f 01>]
20not replacing default route to enp0s3 [192.168.0.1]
21found interface enp0s3 for proxy arp
22local  IP address 192.168.0.30
23remote IP address 192.168.0.31
24Script /etc/ppp/ip-up started (pid 2180)
25Script /etc/ppp/ip-up finished (pid 2180), status = 0x0

Delphius wrote on 2022-06-24, 03:33:

Still going to test it some more, and make sure everything actually routes correctly. But everything seems to be happy now. I am wondering if there is a work around for this, as it would be nice not to have to keep the cache disabled.

No way, cache should have nothing to do with it. I'm guessing power cycling instead of hot-plugging the serial cable might make a difference though...

What kind of speed are you getting for something simple like ftp?