I got this running on a TinyPC x86 device from here: http://www.star.net/people/~mvs/
It's a scriptable Tcl 6.* with almost all the features you would need in an embeddable controller in less than 60K for the kernel. Not too shabby at all.
I've been using a VFD 4 line display I got from BGMicro as the output device but it could support a full VGA text screen if you wanted to hook one up.
I think this would be better than PowerBasic for DOS because it is a scriptable core. New features and functionality can be added without having to recompile the kernel.
Still experimenting with it but my initial impression after 8-9 hours is that it is utterly kick-ass as an embedded control language in real mode DOS.