Advice for a recalcitrant 29c

[PANAMATIK]

(06-06-2019 04:40 PM)[kby] Wrote:  This would make sense for any “C” machine as x has to be part of the Continuous Memory and therefore must be in a CMOS RAM area as the ACT would presumably not be powered when the machine is off.

Except for the first "C" machine HP-25C, where X is not part of the Continuous Memory.

This allowed HP to use the same firmware for HP-25 and HP25C for faster time to market. The CMOS RAM chip of the HP-25C just ignored the Clear Memory instruction which is issued at initialization, while the PMOS RAM chip executes this instruction. This is the only runtime difference between the two machines.

Bernhard