Wow - we had once of those at school - 2mhz 8080 w 48k. ISTR it had some interesting bugs in the BASIC interpreter that would trigger a stack overflow. The first clue was the screen RAM filling with the runaway stack - on it's way to overwrite the as yet unsaved program.
It did a very good job of highlighting just how good the newly released BBC micros were that displaced it.
ah! According to the Wikipedia page, the BASIC interpreter was written from scratch and quite rapidly. It was apparently much faster than the contemporary MS Basic. Wouldn't be surprising if it was buggy, although my dad did a lot of programming on it and without to much trouble as far I remember.