The HP-80 has a (charming) behavior of flashing digits on the display briefly when calculating, for example, SQRTx, much like a programmable Classic while running a program. The HP-35 (and other Classics) don't do this for pre-programmed functions).
Since the HP-80 and HP-35 were basically the same electronics (HP-80 with more ROMs), does anyone know why the different behavior? Seems to me SQRTx (et al) would be implemented the same way on both?