combining hp41 modules into one cartridge

[twdeckard]

Greetings. Can someone point me to any documentation on shoehorning two ROM circuits into one cartridge? I recall a French article that described how careful soldering and perhaps a little sandpaper could put two 4K ROMs in one package.

Also, for someone expert in this manuever can you put an Extended Memory together w a 8K ROM because the address spaces don’t overlap?

Thanks
Todd
https://github.com/twdeckard/HP41CX-SLANTR?files=1
https://github.com/twdeckard/HP41CX-PLAN...PLAN41.rpn (doomed to
remain incomplete and undebugged)