what do you mean ?

if you mean the output of the stuff that is send to the shell/screen
you can use >
if you want acces to the asm instruction executed you need to use the debug version of dosbox (the heavy debug version even. so you would have to compile dosbox yourself to get it). That version has a log #number command

it logs #number amount of cpu instruction + register values to a logfile

I try clarify
My dos software generate a lot of the text printouts, I want keep it all to log file.
solution like >logfile.txt not working - I see only empty file

well if you are using 0.63 then the application outputs in a different way then normally.

else use 0.63 as it didn't work before.

I use ver 0.63

Can I collect all text data that I see on the screen then software running?
like log file or something like this

If it uses direct screen access you're pretty much out
of luck, did logging work in any way under real dos
with your program?

wd

what you mean "logging under real dos"?
software doesnt have own logging functionality

If it neither provides a logging function, nor supports
output redirection (like "prog.exe >log.txt") it is not
possible as is to capture the program output, as it
likely uses direct access to the screen.

wd

May be..
but I can manualy Mark\Copy outputs in DOS window and after that I can Paste it to notepad like normal text - you think it isnt possible do the same automated?

You can do that in a dosshell of XP or Win9x, but dosbox
renders the screen in a way as a bitmap, so you can't
extract anything automatically.
You could dump the text screen (there were dos-tools
available, maybe pcxdump can grab textmode), but that
is not really logging.

Maybe you can tweak your program in a way that it
runs in an XP-dosshell where you can copy/paste the
window, or maybe sb else has an idea (would help
if you'd tell the name of the program).

wd

OK I try dos-based screen grabber first, it can keep the screen in text (asci) mode. thanx
PS Its good idea add function - screen capture in text mode - to DOSBOX

It'd pretty hard to have a textmode-screengrabber that is
multi-platform (one of the dosbox goals).
If you just need screen-capturing, that can already be
done, look into the readme how exactly.

wd

Yes I know that DOSBOX can make screenshots, but it make only in graphical mode - I told about text (asci) mode screenshots function