Comment by allertonm

Yeah, me too... TI-51 III (aka TI-55 in US) in the late 70s - belonging to my father, who had it for his job but never got to use it much because I was always playing with it. He later got me a copy of this book - http://books.google.ca/books?id=ySZhMJrzhw4C&pg=PT48&... - and that's really where my computing career began.