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HP-45 Internal Pointer Operations
04-25-2023, 04:26 PM (This post was last modified: 04-25-2023 05:23 PM by brouhaha.)
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RE: HP-45 Internal Pointer Operations
My apologies, everything I said was WRONG with regard to the Classic series (ARC/CTC), including the HP-45, and you shoul pay attention to what Teenix said instead.

In the Classic series, P can have values of 14 and 15, and doing a load constant under those conditions apparently does nothing, as Teenix said.

The wrapping of P on increment from 13 to 0, and on decrement from 0 to 13, was introduced in the Woodstock ACT processor.

The Classic series ARC/CTC was the first that I simulated, and I haven't dealt with it in so long that I'd forgotten that it behaves differently than the newer processors. I had to look at my source code (Nonpareil src/proc_classic.c).

Sorry for the confusion! My apologies to Teenix for contradicting his entirely correct statement.
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RE: HP-45 Internal Pointer Operations - brouhaha - 04-25-2023 04:26 PM



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