Don't use Dosbox for mission critical stuff. Seriously, it is not meant for that, only for games. You better build a dedicated dos machine for that.

What Dominus said.

Also, be careful if you're using a USB-to-serial adapter; in my experience they may not work as well as a real serial port, like the kind you can get on a PCI I/O card.

In fact, we're already working in a critical mode.
Dosbox is just a mean to give some month to replace all the supervision.

The new PC is equiped with pci serial cards and I just want to understand the message:
Serial1: Errors:Framing 97, parity 0, overnum RX:0 <IF0:0>, TX=0, Break 67
in order to fix it.
I really thank you for your advice, and I'm working on several fronts (virtual box is another one for example)

Thank you
Marcel

What I meant is that Dosbox might not work precise enough to be trustworthy. The question is not whether it will break something in your production but when. Just build another dos machine and have that ready when the old one dies.

I know that it is not recommended but the IT maintenance team have already perform test on newer PC and it doesn't work ==> too fast for the hardware (not the pc but the other devices)

If I buy an old pc to a broker, it's also risky ==> an old PC risks to die like mine

So I really ensure you that Dosbox is one of my low risk exploration.
Do you have any idea about the error message:Serial1: Errors:Framing 97, parity 0, overnum RX:0 <IF0:0>, TX=0, Break 67

Thank you

If I buy an old pc to a broker, it's also risky ==> an old PC risks to die like mine

so it already died? But yes I didn't mean to suggest you use a new PC but that you keep another old Dos machine as backup in case the main machine dies or, better, build a third one as well. If all you need is DOS this can be done without too much of hassle. I honestly can't believe you are eager to trust your production to an emulator instead of the real thing...

The error message doesn't tell me much but perhaps the machine you are testing on is also too fast or you need to test out the various speed settings for the com ports in the device manager.

so it already died?

No, the former one died last summer, and its substitute is running 24h a days, 7 days a week since july 2011.
If it crashes, we have no more spare parts...

The error message doesn't tell me much but perhaps the machine you are testing on is also too fast or you need to test out the various speed settings for the com ports in the device manager.

OK, I'll try, thank you

is running 24h a days, 7 days a week

Really for this kind of work... *sounding like a broken record* ... use a real PC and not Dosbox...
Good luck

I'm glad to tell the forum that the new PC is plugged and works with the 0.74 version of DOSBox.
In fact the error message is nothing
😁 😁 😁 😁

Let's see how it works after 21 days of continuous usage.
Some important variable(s) signflip then if I recall correctly.

A vaincre sans péril, on triomphe sans gloire (le Cid, Corneille, 1637)
to win without risk is to triumph without glory

The risk my old computer crashes is a million times worse than restarting a software in less than 2 minutes.

So let see.
Thank you for your help and your advice.