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Where is NOP on the HP-67 ?
01-07-2021, 11:20 PM
Post: #17
RE: Where is NOP on the HP-67 ?
(01-07-2021 10:36 PM)Gene Wrote:  Gene: You are quite right, Valentin! An "A" in an HP-65 program is equivalent to GSB A or XEQ A.

Wanted to state this for the record even though the program now works.

And sometimes it's equivalent to GTO A, if the lone A is encountered while already inside a 2nd-level subroutine. And if LBL A doesn't exist anywhere in the program, it has some other rather unique - and useful - behavior that surprisingly isn't a label-not-found error. Wink

The 65 is a rather odd beast in quite a few ways. For additional fun, take a look at the HP 65 hyperbolic functions program in 65 Notes/PPC Journal (don't have the issue number in front of me - I'll dig it up if nobody else finds it). See if you can figure out how the calls to LBL C work, and why the program contains these three steps which DON'T result in an infinite loop/stack overflow:

LBL
C
C

It's sometimes rather tricky to convert 65 programs to newer machines because of all these really interesting quirks that were exploited to their fullest.

Another interesting trick:

g
DSZ
NOP
GTO
A
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Messages In This Thread
RE: Where is NOP on the HP-67 ? - teenix - 01-06-2021, 10:20 PM
RE: Where is NOP on the HP-67 ? - [kby] - 01-07-2021, 02:44 AM
RE: Where is NOP on the HP-67 ? - Gene - 01-07-2021, 10:36 PM
RE: Where is NOP on the HP-67 ? - Dave Britten - 01-07-2021 11:20 PM
RE: Where is NOP on the HP-67 ? - [kby] - 01-09-2021, 06:40 AM
RE: Where is NOP on the HP-67 ? - teenix - 01-07-2021, 11:36 PM
RE: Where is NOP on the HP-67 ? - teenix - 01-10-2021, 11:59 PM



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