71B vs 75D

[hth]

(04-15-2021 11:10 AM)Martin Hepperle Wrote:  In my view, the Capricorn CPU is remarkable technology and the 75 is an interesting bridge between the pocket calculators and the Series-80 desktop computers.

Unfortunately the RAM capability of the 75 is severely limited - the RAM also serves as a file system, like on the 71. They could have done better by adding an additional memory controller.

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.

Which leads me to think about the series 80 computers, but I do not fancy hunting down old hardware that is bulky and may need repair. Not even sure if they are collectable and expensive as well.

I wonder if there is any FPGA implementation of this ISA, someone could replicate something new and "modern" retro around it? I think that is what I really want, then perhaps an HP-75 to complement it.