71B vs 75D

[Martin Hepperle]

(04-15-2021 04:32 PM)hth Wrote:  Yes, this was my thinking also. I am very much into ISAs and architectures and Capricorn is really interesting. I think the HP-75 is let down by the lack of RAM and I am not sure if it is possible to replace ROMs, there seems to be no plug-in feature.

You have 3 ROM plugin ports - ROMs are bankswitched, all very similar to the Series-80s.
One could also make something like the ROM emulator which was available from HP and plugged via cable to the ROM ports or something like the "Modem/RAM-Disk Pod".
The ROMs have some "intelligence" as they monitor a certain address and switch themselves on/off as needed.
The difficulty is probably more in finding or making proper connectors. Today it could be easier with 3D printing and individual contact springs?

Martin