Question about TI calculator

I became the grateful recipient of a TI Programmer today. A buddy at work said "here, you like calculators, right? Better than throwing it away." Well, I said "thanks!" Now, in looking about the internet for some info on the battery styles for these things, I have a couple of questions that I cound't find the answer to. This calculator has a battery pack called BP-8 which has 2 AA ni-cads and a small circuit in it. It connects to the calculator internally with a connector that would also mechanically mate to a 9 volt battery. Now I would not expect a 9 volt battery to work where 2 AA's work, but I'm not sure. In looking at Gene's web site he says the BP-8 is also used on the TI-30 and I see TI-30's on ebay saying that they work with 9 volt batteries. I will replace the two AA's with new ones. That should make the BP-8 good again. I guess the is a roundabout way of asking for some background on the power requirements of this calculator. Unfortunately my buddy had lost the AC adapter (apparently it was an AC-9132, thanks Gene!). So I'll be looking for one of those. 5.7v, 240ma, and that small 2-pin connector. Thanks for any help.