HP 71B Diagnostic ROM

[Joe Horn]

(04-13-2014 07:35 PM)Dave Frederickson Wrote:  My explanation for Joe's Frankencalc is that at one time it had a lobotomy. Someone repaired the calculator by replacing all the ROMs. Joe, does your 71 have bright or light colored key legends?

It has the same brightly colored key legends as my 1BBBB machines and your top photo above. It also has only one screw in the battery compartment, not three, same as the 1BBBB machines. However, its battery terminals have foam pads (like in your bottom photo), not springs (like my 1BBBB machines have):



So it looks like the change from battery compartment springs to foam pads was not simultaneous with the change to plastic backs. IMHO it was a stupid change; springs last forever, but foam deteriorates and so does the glue that holds the little metal contact plates onto the foam. But I digress.