The HP-65 had a program memory for up to 100 instructions of 6 bits which included subroutine calls and conditional branching based on comparison of x and y registers.
A program could be saved to mylar-based magnetically coated cards (71 mm &times; 9.5 mm), which were fed through the reader by a small electric motor through a worm gear and rubber roller at a speed of 6 cm/s [REF].