I bring a few decades of embedded work to the table here (who just said 'pompous' on another thread??? ;-)), so I'll take a stab at this one. First off, no 8x51 is going to give you the kind of juice you need. A few variants can have more than 64K of total memory space, but they're rare and the BS is not one of them. You can write an interpreter with similar syntax, but it'd be crippled and it wouldn't have the bit-banging routines you need most, unless you write them.

That said, there are a host of 486-on-a-chip boards (see http://soekris.kd85.com/) that will give you a tiny BSD kernel like PicoBSD and your entire Perl environment or http://www.ampro.com for examples of units with vga and keyboard connectors so you can have a whole pc on your bot.

With PicoBSD (see http://www.freebsd.org/~picobsd/), you can build an entire deployment system on your pc and d/l it to a floppy or a flash disk for your embedded system, if it's 'headless', i.e. no kb and monitor.