KIT K6063 Big Display with memory, how?

Ref : Kit K 8063

Great display for info purpouse, but we like to see it even bit better with small chance of operation.

When disconnecting the computer line (rs232) or shut down the computer the Display will stay to showing last value put in . And starting up the computer it’s possible to continue from the last value what was in !

So we need small memory to put in, is this possible to chance the chip PIC16C630 to one with the mem ???
Which one ? Or do we have to make other chances to schematics ?

Best regards
Matias