SR-52 conditional trick (absent from the 58/59

[Matt Agajanian]

Sorry for the misleading title. The features ARE available in the 58/59 series. Within chapter 12 of the SR-52 manual is the topic of Indirect Addressing. A little bit in there is the operation of indirect addressing of conditional and looping tests. At page 127 starts the topic of indirect conditional & looping constructs.

For example:
2nd IND 2nd if pos 04 would branch to the address in R04 is the display is positive.
2 IND 2nd dsz 15 would transfer to the address in R15 if R0 is non-zero.

Only, this time for the 58/59, the Indirect instruction follows the conditional/looping instruction.

2nd x=t 2nd IND 25 would branch to the location specified in R25 when the displayed value equals the value in t.
2nd Dsz 3 IND 17 would branch to the location in R17 when R3 isn't zero.
INV 2nd Dsz 5 IND 39 would branch to the location in R39 when R5 is zero.

[Maximilian Hohmann]

Hello!

(07-29-2022 08:22 PM)Matt Agajanian Wrote:  Why wasn’t this feature implemented in the 58/59 series?

Maybe because they implemented something even more quirky - see posting #4 in your other thread on that topic: https://www.hpmuseum.org/forum/thread-18598.html ;-)

Regards
Max

NB: I wonder how many users of these calculators (any one of them) ever used these features other than for trying them out once whilst working their way through the manual - as we would do in those days. I used the Ti59 for about a decade but can't remember to ever use this kind of branching mechanism.

[Matt Agajanian]

UPDATE!

The features ARE available in the 58/59 series. Within chapter 12 of the SR-52 manual is the topic of Indirect Addressing. A little bit in there is the operation of indirect addressing of conditional and looping tests. At page 127 starts the topic of indirect conditional & looping constructs.

For example:
2nd IND 2nd if pos 04 would branch to the address in R04 is the display is positive.
2 IND 2nd dsz 15 would transfer to the address in R15 if R0 is non-zero.

Only, this time for the 58/59, the Indirect instruction follows the conditional/looping instruction.

2nd x=t 2nd IND 25 would branch to the location specified in R25 when the displayed value equals the value in t.
2nd Dsz 3 IND 17 would branch to the location in R17 when R3 isn't zero.
INV 2nd Dsz 5 IND 39 would branch to the location in R39 when R5 is zero.

[pauln]

If I remember correctly, every single TI-59 instruction that has a numeric operand (Fix d, RCL dd, GTO ddd, ...) has an indirect version. This means that you can write instructions such as:

"INV Ifflg Ind 01 Ind 23"

Even if some of these instructions are very rarely used, I find this consistency quite admirable, as one doesn't need to guess whether such or such instruction has an indirect version. It does.