HP-71B and some (to me) interesting modules

[Garth Wilson]

Maybe someone here knows otherwise; but I think the batteries in the RAM modules are only there to hold the memory if you remove the modules from the computer such they they would not be able to use the computer's power. As long as you leave the module in the port and the computer can keep its onboard RAM and clock alive, the modules should be fine without their own battery. I have a CMT 96K card-reader-port RAM and 64K front-port RAM in mine.