Can't download with ZModem

[SkybuckFlying]

Describe the bug

ComPort1 setup in Dos Box X Config: serial1 = modem listenport 23 serial2 = dummy

Trying to download from a BBS.

Telix v3.15 and Telix v3.51 tried and Telemate v4.21.

atdt scenelist.org:23

BBS seems to work fine.

Except downloading with Z-Modem protocol does not seem to work.

Any idea what could be wrong ?

Steps to reproduce the behaviour

Download the software mentioned above, setup com port in conf... try using output = surface as graphics technology.

Expected behavior

ZModem should work/download ?

What operating system(s) this bug have occurred on?

Windows 7 Home Edition

What version(s) of DOSBox-X have this bug?

v2022.12.26

Used configuration

No response

Output log

No response

Additional information

No response

Have you checked that no similar bug report(s) exist?

• [X] I have searched and didn't find any similar bug report.

Code of Conduct & Contributing Guidelines

• [X] I agree to follow the code of conduct and the contributing guidelines.

[dajhorn]

The web interface into this BBS is broken and the telnet server doesn't accept anonymous connections, so there isn't enough detail in this ticket to diagnose the issue.

Do you have an example of a public BBS where zmodem doesn't work through the emulated serial port?

[scrutinizer80]

Tried downloading from Another Millenium BBS (another.tel). Zmodem doesn't work using Terminate. It gets constant CRC checksum errors. All menu related functions are working fine. Tried multiple other protocols (Ymodem / Xmodem) - same result.

[scrutinizer80]

@dajhorn No matter which BBS. Zmodem (and other) transfers do not work on dosbox-x for some reason. Tried both Linux and Windows 11 builds.

[l0rdnic0]

Can confirm that Zmodem regardless of type built in, or external protocols (PDZmodem, CEXZ Zmodem). I have tried in a windows Dosbox-X and Debian build. In my use case I have an image file hdd.img. Inside this image is a Dos 6.22 bootable image and a Wildcat BBS system. I have tried with and without Fossil drivers (X00 and BNU are the two fossils I have used) and each time I see CRC failures unless I'm transferring tiny text files.

If I extract the contents of this hdd.img file and past them on a legacy physical computer the BBS works as expected.

I'll note.... I have used or attempted to use many combinations of the following two strings and others nullmodem telnet:1 nonlocal:1 port:23 usedtr:1 modem listenport:2323 inhsocket:1 usedtr:1 nonlocal:1 sock:0