I installed a FreeDOS at my embedded system. I need to verify the new touch panel which is connected to my target through RS-232 (which should be COM1). If it's a Windows system, it's very easy because lots of terminal tools can check binary codes from serial ports. But on DOS, it's old system. I don't know if there is any tools I can use to show binary data from the touch panel connecting to system through serial port.
SSHDOS, which is a terminal software for DOS built on the code of the popular Putty application, should be a good option for you.
You can download it free from their site