It is more convenient for the elderly to play chess with IPAD than with computer. There is QQ chess on the IPAD, which is more conducive to blood circulation than using a mouse. Another advantage is that you don't have to keep a stiff sitting position for a long time, which is good for the cervical spine.
Buy a second-hand IPAD 1, which is cheaper than a computer. If you can afford the IPAD2, you can also video with the elderly in the future. Of course, if you buy an IPAD, you have to spend money on a wireless router, which costs more than 100.