Thank you Jim for the technical explanation as to why Zmodem is acting so ... unstable. Now in my case I have set up a little BBS locally on my LAN just to be able to transfer files between the machines, and downloading with ZModem poses no problem at all, but uploading constantly fails.

I was thinking maybe it would be possible to create a port of the SXYZ(?) protocol used in SyncTerm as states to have fixes for using ZModem over TCP/IP/Telnet (and testing it seems rock solid) but unfortunately I do not have the knowledge necessary to even begin making a port of this protocol for the Amiga....

Will try Y-Modem to see if I can have better luck with that.

Are you by any chance using the serial.device from OS3.9 BoingBag 2? If so, downgrade to the one from BoingBag 1.

Yes I think I am. I have AmigaOS 3.9 and "all the boingbags installed".
Will look at trying to replace the serial.device with the one from BoingBag 1 as you suggest and see if that works better.

Thanks.

... and I COMPLETELY forgot about this... UNTIL now in 2020!
Will take a look at it tomorrow :)

Still can't get uploading using any protocol working?!
 

I tried downloading BoingBag 1 but I couldn't find a serial.device inside that archive. Do you know where I can find the serial.device that you recommend I downgrade to?

Uploads still consistently fail with all different protocols that I have tried. I even tried connecting at 2400 baud here to see if that helped and it got some ways into the file, but then started resending and stacking up errors.

Also when I am doing these tests they are ONLY to my own local BBS setup on my PC on the local LAN so the packets are travelling only like 1 hop.

If anyone knows if there is ANYTHING to be done about this so that I can get uploads to consistently work over the LAN that would be wonderful.

:help

here's a little update on the questions

wifi modem command to activate negation on some models is ATNET1 this is not often explained in the instructions any way to disable is ATNET0

Aminet you can find many variants of serial.device 8n1.device is one of the baudbandi.device works too

unfortunately, even the transfer protocols and negation are the same at both ends. the terminals have features which also need to be adjusted before the file transfer reliably unfortunately i can't give clear instructions on how this happens because i haven't tested all of them even with Term there are big problems depending on which machine i use it even though the settings should be identical

There are also big differences between versions of Zmodem, some versions don't work at all
yes I no longer remember what differences they had, I should look and refresh my memory on that

I'm my experience you get better/worse results depending on the implementation of zmodem at both ends. I recommend xprzmodem version 2.61 (the one that comes with term). This is what I use with my bbs and generally works well. It also depends on what client you are using.

Hello again!

I know I haven't written anything about this in a very long time now, but I started messing about with it for a bit tonight again.

The thing that I have done is to set up a very simple local Telnet BBS on my Windows PC using Mystic BBS only to be used and accessed over the LAN for ease of transferring files (and for experimenting) but even now I haven't gotten ZModem to work properly with it just doing resending.

I also tried Y-Modem but that cancels the file transfer before it even has a chance to begin. Tried connecting to the BBS using DCTelnet and AmTelnet for a test but even though that seems to be working it completely defeats the purpose of me buying a WiModem232!

I would have thought ZModem would have a chance of working properly since the machines communicating is only on the local LAN so the datapackets are not travelling around the world....

Also I have upgraded the WiModem to the latest firmware.

Afaik the timing sensitivity of zmodem prevents it from working reliably over Telnet.
What does seem to work is Kermit.

I wonder if the reason Kermit is working is thanks to The Rainbow Connection? ;)

Seriously though I did keep on messing around with this for a bit yesterday, and using NComm with XPRSZModem.library or XPRZModem.library at 38400 baud made ZModem stable (enough) to finish the transfers attempted with 1-5 errors/resends.

Have not yet tried using an alternative serial.device to see if that makes any difference. Also the BBS package I have installed on the PC side does not support Kermit protocol so even if I wanted to use that it's not an option.

I wonder if it would be possible to write a ZModem implementation adapted for use over Telnet/WiModem232 (SyncTerm on the PC side has an adapted ZModem made to run well over Telnet. Don't know enough about programming to attempt something like it for the Amiga sadly...)

Where do I find this serial.device? I did look through the BoingBag 1 archive, but I cannot see a serial.device anywhere in there. If someone knows where I can find it to try this suggestion let me know okay?

:help

As mentioned previously in this thread the version of xprzmodem that comes with term works just fine over telnet. I have only tried very briefly with a wifi modem though and I was never able to get stable transfers so I think there may also be more issues than just the zmodem problem.


Zmodem can work fine over telnet, if the receiver is able to support overlapping serial and disk io and then no ack packets are needed and the sender can just keep sending data until it reaches the end or it receives a packet to say there was a problem. This eliminates the problems with timing sensitivity

This sounds like transfers from/to ram: could work more reliably?