In order to celebrate the 35th Anniversary of the first HP Handheld Calculator, the HP people decided to present a new calculator today – the HP-35s.

On top of having the retro style as the first handeld calculator (HP-35), the new 35s is the most advanced scientific programmable calculator on HP - a good pick as a birthday gift.

Featuring ample memory for keystroke programming, equation solving and more than
800 storage registers; 100 built-in functions; and a large, two-line display with
adjustable contrast to easily view entries.

The anniversary calculator HP 35s will cost $60, the release date is late summer.

HP - PDF file.