Processor Instruction Sets

[brouhaha]

Only the Woodstock/Topcat series, 19C, and 67 use the ACT processor. Despite the physical packaging, the 67 is NOT a Classic series machine, at least from an electrical and architecture view.

The Spice (30) series don't use an ACT, but they are architecturally compatible with it other than bank switching and self-test.

The Classic series, 46, 81, 1722A, and 9805 use the ARC and C&T chips, with a different architecture (instruction set and encoding).

The HP-01 uses it's own architecture, 48 bits wide rather than 56, and it's somewhere between the Classic and Woodstock architectures.

The 41 and Voyagers use Nut, also with a different architecture.

Even though the Classic, Woodstock, and Nut architectures aren't identical, they are all quite similar The big divergences from the original 56-bit architecture are Capricorn, as used in the 75 and Series 80, and Saturn, used in the 71B, Pioneers, 18C/19B/19BII, 28C/28S, 38, 39, 48, and 49, and then 6502-based and ARM-based calculators.

And of course the "big" desktops (9100, 9810/20/30, 9815/25/35/45, etc) use entirely different architectures from the handheld and handheld-derived machines.