I think the T70 used FD lenses, there are a couple of Canon bodies that will work with these, but the newer EOS range won't. There are adapters around but from reports they don't tend to work that well and are very pricey. Better to spend the money on the newer lenses.

Your Camera must be very old ... I only grown up knowing EF and EF-S mount
and they been around 15-20 years?

If you thinking of buying a new Camera, the decision usually come down to Full Frame or Crop Sensor ....then pick the model in that Sensor range ....

Full Frame aim at professional end and do offer superb quality in shooting portrait and in environment where that extra large sensor helps, like in a low light environment...
but having extremely good lenses make it less of an issues.

After that the decision comes down to which lenses to buy EF or EF-S range
EF mount can mount on both Crop and Full Frame sensor camera, EF-S can only be mount on Crop sensor camera ...

I would spend most of my money on lenses, the body technology change rapidly
every few years....but Lenses technology rarely change...

I got this lenses
http://www.canon.com.au/For-You/Camera-Lenses/EF70-200mm-f28L-IS-II-USM-Lens

the one before that release 10 years ago and still a superb lenses, the new one is of course better but not twice better, they improve on a few things and that is it...
the limitation is in the glass and there is not much more you can push a already good glass.

Currently I have a Canon 7D, but I buy most of my lenses in professional L range EF mount so if one day I decided to go with Full Frame Body Lenses isn't an issue..

I have the Cannon T70 and others aswell sitting in a cupboard at home. I had the AE1, AE1 Programme and then got the T70, even managed to find a "Command Back" for it in Singapore years ago. Used to take wedding photo's with it and everyone raved about the quality.

Then, technology just superseded it and left it behind. I've got doublers, 1000mm Catadioptric lenses, filters, zoom lenses etc etc etc and they might aswell be paper weights now

When Cannon changed to the EOS range they changed all the mounts and front mount fittings and rendered all the superseded gear useless.

Ah well, thats progress!!!!