(HP71B) ASM question

[J-F Garnier]

(07-30-2024 06:47 AM)brouhaha Wrote:  ... the Nut processor as used in the 41C/CV/CX, 10C, 11C, 12C, 15C, and 16C, [...] was derived from the Woodstock architecture,(HP-25, HP-67, etc.), which was derived from the classic architecture (HP-35, -45, -46, -55, -67, -70, -80, -81).

If you want to go back even further, the HP classic archtiecture was inspired by the Fairchild PPS 25 architecture, which is even more obscure than any of the HP architectures. Whatever assembler(s) existed for the PPS 25 is lost to the mists of time.

I didn't know the connection to the Fairchild PPS 25.

Do you know where the Capricorn CPU architecture, used in the Series 80 and the 75C, comes from?
It has some loose connections with the calculator architecture with its capability to handle a whole 64-bit register operation in one opcode, but has many distinctive capabilities and is less calculator-oriented with no dedicated register fields but a flexible 'multi-byte' mode.
I never found anything close. Did HP develop it from scratch ?

(07-30-2024 06:51 AM)brouhaha Wrote:  I forgot to mention, a C compiler actually exists for the HP Nut architecture:
https://www.calypsi.cc/
It's not open-source, but the binary build targeting Nut is available free-of-charge.

I remember there were attempts to write a C-compiler for the HP-71B.
None never became usable, but a tentative is still described here:
github.com/hp71b/fnc

J-F