I recall seeing some plugin to integrate the DOSBox debugger with IDA? Maybe some of the work has been done already.

Last time I used the debugger extensively, I wrote down these enhancement ideas:
- step return
- memset
- nop instruction
- show delta cycles (i.e. how many instructions were executed between breaks)
- some kind of stack view (and navigation between frames)
- run to cursor
- clear screen

- I/O trapping 😉

at the moment an assembler is not available, so make a simple patch may be very difficult.

Thank you all for your answers.

VileRancour wrote:

I recall seeing some plugin to integrate the DOSBox debugger with IDA? Maybe some of the work has been done already.

You are probably refering to Eric Fry and wjp's idados. I didn't knew about that. It's certainly worth it to have a look at the commits.
But it's focused on IDA for now, I can't afford and I would like to use it on UNIX with FOSS tools like radare2 or gdb.
I'm not surprised to see this has been done by wjp since he is a ScummVM developer.

danrevella wrote:

at the moment an assembler is not available, so make a simple patch may be very difficult.

I'm not aiming at making a simple patch, but a separate program. DOSBox has it's own goal.
I have forked DOSBox from SVN at https://github.com/jessetsumpter/dosbox-fork.
Pull requests are welcome.

danrevella wrote:

at the moment an assembler is not available, so make a simple patch may be very difficult.

Please excuse... as always I was not enough clear...
I would like dosbox -debugger implement an internal assemble, so f.e.when we're debugging a dos program we may patch it on the fly directelly in the debugger. This operation at the moment is only possible writing memory location in hex dec format, while i would like the possibility to directelly assembly patch to the dos program I'm just debugging..
Thaks for your project!!!