However, I dont think emulation is the right way to replace a dos computer, virtualisation is better. You can install DOS in a VMWare VM easily, whilst emulation like DOSBOX is very good, its still has some issues, a VM will get around most, if not all issues you have with dosbox.
DOSbox is a total cpu hog, especially if you set the cpu cycles in the config file to a level where it doesn't look like you're watching the beginning of an Alien movie printing out stats on the Nostromo slightly faster than you can read. On Linux I run a 1-2-3 clone and Wordstar in Dosemu windows, because if you're in Win3.1 under DOSbox and you launch a non-Windows app the whole window switches to that app and you can't switch back When I absolutely must go to Windows 3.1 I'll fire up a instance of DOSbox but I look at htop when I do and I'm amazed. And it's not any better using DOSbox under 64 bit Win7.