Simple Programming Language or Set of Programming Commands

[Claudio L.]

For 1k to 2k of code, you are probably looking at some Forth-type language, where there's no interpreter or execution loop. For Basic, some tokenized implementations used to fit in 16 kbytes of ROM (like the original ZX Spectrum 48k) but I don't know of any open source code out there that can be that small.
Try uBASIC? I don't know if it's small enough.