I've got 2 CE's (one black one which broke, and my "signature" mint CE) and a Casio fx 115es PLUS (scientific) and a four-function (Casio SL-300SV, bought for AP Bio)

ProgrammerNerd: The abacus was a good one (I have one too ) but the second?! If you actually have one in your basement, that would be cool!

Here’s a pocket abacus I have in my calculator collection. You can carry it in your pocket just in case you come across a situation where you need to do some quick calculations. The abacus looks a little distorted because I had to get close for the picture. It’s also heavy because it’s mounted on a 1/2” marble base. I think it was originally used as a paper weight.

I have

2 TI 83+
1 TI 84+CE
1 TI 86
1 TI nspire CAS


Take note that only the TI84+CE is technically "mine." (I got it for christmas)

Here’s the latest TI calculator added to my collection. It’s a TI SR 10. I was at a flea market and the seller wanted $3 for it. I figured the batteries were probably corroded and it didn’t work. I noticed there was a plug for a charger, but he didn’t have it. I offered $2 and he accepted. When I got home and was taking it out of the car, I noticed a 0 on the display. Apparently I left it turned on and I didn’t see the 0 because we were in bright sun light when I was looking at it. When I took the back off, there were 3 regular 1.5 volt batteries. I guess I didn’t need the charger anyways. I was buying it just because it was old and not for it to work. I guess I lucked out on that one.

Wow that's quite a find! Those go for ~$10-20 on ebay! You're especially lucky the batterys weren't dead. How well does it perform? Is it quick at all?

There’s a noticeable delay for the calculations, like about 1/10 second. It also doesn’t have good precision. If I take the square root of a number, then square it, the result isn’t exactly what I started with. But it’s OK for a 45 year old calculator. I’ll probably pull the batteries out of it and put it with all my other calculators.

Well, better late than never!

I have a TI83+ and a TI84+CE with ambitions to get a Nspire CX CAS, the Numworks calc, and the HP Prime.

I just have a normal calculator, two scientific, and then three graphing.
I used to have an abacus, but it was given to a friend.
All are in perfect working order!
I have the covers for all except the TI-82. (Though the one for the 84+CE isn't in the image.

That's actually a pretty nice little collection. I kinda want a CE.

I've gotten a lot more serious about collecting, and have acquired a lot more calculators. I mostly try to get early revisions of various calcs. I have a profile on tiplanet's collection site where I listed some of my calcs (I didn't bother listing the same calc 10 gillion times, so if I bought a classroom set, I only put one or two from the set).
Here is a link to that

One thing I've struggled with is sellers not shipping to Canada. A solution to that has been to send some calcs to non-Canadian members, specifically geekboy1011, KermMartian and Pieman7373 (Big thanks to all three of you ) and then work out how to get the calculators to me.
We arranged to meet up at Maker Faire this year, which means that I got three more calculators
Here is my Maker Faire haul:

1. Ti-nspire CAS + (PVT1.1, S-0906)
   
2. Ti-92 (ROM 1.2, I-1195)
   
3. Ti-92 (ROM 1.4, I-0196)
   

I quite like the idea of gathering all the hardware revisions of a calc, but that's still a little bit out of reach for now. Same thing for ROM revisions, except that that's even a little bit harder because you can't always tell with 100% certainty what the ROM revision of a calc is just by looking at the serial number/datecode. This means that gathering all ROM revisions could entail having to buy a few calcs to gather a single ROM revision.