TI-59 most keypresses for a single instruction

[Gene]

"The more flexible storage format for programs in the TI-59 allowed combining more keys into one instruction. The longest instruction required eleven keypresses, re-using the shift keys four times."


The above is from: http://www.like2do.com/learn?s=HP-41

I am trying to think what this would be. INV 2ND PROD 01 is five keystrokes but takes two steps.

Any ideas or is this a mistake above.

[Thomas Okken]

Add "ind" and you're up to 7 keystrokes: INV 2nd Prod 2nd Ind 0 0

But 11 keystrokes for one command? *headscratch*

[Thomas Okken]

INV 2nd If_Flg 2nd Ind 0 0 2nd Ind 0 1

If the flag pointed to by register 00 is not set, jump to the line pointed to by register 01.

[Gene]

That may be it, Thomas, but I think that occupies two program steps.

[Thomas Okken]

Six, actually:

INV
2nd If_Flg
2nd Ind
00
2nd Ind
01

But it's still one *instruction*.

[Gene]

Oops. You are quite correct of course. Apologies.

I think we found it.

If there were ever an illustration of why the HP 41 was so much easier / (ahem) better than the TI-59 style approach, this is it.

Well, and using INV x-bar for standard deviation. That's pretty bad too. :-)

ty for clearing up the mystery for me.

[Thomas Okken]

My pleasure! I've always had a soft spot for the TI-58/59, because of their raw power.

But there is a lot to be said for

FC? IND 00
GTO IND 01

Which is four bytes,
rather than

22
87
40
00
40
01

which takes up more memory and is harder to read. :-)

[Dave Britten]

(12-14-2017 04:56 AM)Thomas Okken Wrote:  My pleasure! I've always had a soft spot for the TI-58/59, because of their raw power.

The 59 certainly outdid the 67 in programming capability, even if not hardware quality. The 41C, of course, trounced them both, but TI's 95 compares very favorably to the 41 and 42 (despite its ridiculous size).

(12-14-2017 04:56 AM)Thomas Okken Wrote:  But there is a lot to be said for

FC? IND 00
GTO IND 01

Counting keystrokes, you've got "Shift FLAGS [FC?] . 0 0 Shift GTO . [IND] 0 1". So that's 12, to the 59's 11!

[Thomas Okken]

(12-21-2017 01:14 AM)Dave Britten Wrote:  

(12-14-2017 04:56 AM)Thomas Okken Wrote:  But there is a lot to be said for

FC? IND 00
GTO IND 01

Counting keystrokes, you've got "Shift FLAGS [FC?] . 0 0 Shift GTO . [IND] 0 1". So that's 12, to the 59's 11!

The HP-41 doesn't have menus, so it's XEQ ALPHA F C ? ALPHA instead of Shift FLAGS FC?, for a total of 15 keystrokes. But I was referring to the 41 version being easier to read.

[Massimo Gnerucci]

(12-21-2017 02:29 AM)Thomas Okken Wrote:  

(12-21-2017 01:14 AM)Dave Britten Wrote:  Counting keystrokes, you've got "Shift FLAGS [FC?] . 0 0 Shift GTO . [IND] 0 1". So that's 12, to the 59's 11!

The HP-41 doesn't have menus, so it's XEQ ALPHA F C ? ALPHA instead of Shift FLAGS FC?, for a total of 15 keystrokes. But I was referring to the 41 version being easier to read.

Shift GTO . Σ+

11, on par!

[Dave Britten]

(12-21-2017 02:29 AM)Thomas Okken Wrote:  The HP-41 doesn't have menus, so it's XEQ ALPHA F C ? ALPHA instead of Shift FLAGS FC?, for a total of 15 keystrokes.

Oh yeah, forgot FC? wasn't on the keyboard.

(12-21-2017 02:29 AM)Thomas Okken Wrote:  But I was referring to the 41 version being easier to read.

Yup, no argument there. (But the TI-66 comes close to bridging the gap, and the TI-95 isn't too shabby either.)

[rprosperi]

(12-21-2017 09:13 AM)Massimo Gnerucci Wrote:  Shift GTO . Σ+

11, on par!

My hero!!!

Thanks Massimo for restoring the 41C's honor. That was a close call...

[Thomas Okken]

(12-21-2017 02:20 PM)rprosperi Wrote:  

(12-21-2017 09:13 AM)Massimo Gnerucci Wrote:  Shift GTO . Σ+

11, on par!

My hero!!!

Thanks Massimo for restoring the 41C's honor. That was a close call...

I'm aftraid not, we haven't been counting very accurately...

HP-41: XEQ ALPHA F C ? ALPHA Shift 0 0 Shift GTO Shift Σ+
13 keystrokes
HP-42S: Shift FLAGS FC? . 0 0 Shift GTO . IND 0 1
12 keystrokes

Compliments to Massimo for using Σ+ as a shortcut for 01. It's been so long since I've used a 41 I had completely forgotten about that!

[rprosperi]

(12-21-2017 02:56 PM)Thomas Okken Wrote:  I'm aftraid not, we haven't been counting very accurately...

HP-41: XEQ ALPHA F C ? ALPHA Shift 0 0 Shift GTO Shift Σ+
13 keystrokes
HP-42S: Shift FLAGS FC? . 0 0 Shift GTO . IND 0 1
12 keystrokes

Compliments to Massimo for using Σ+ as a shortcut for 01. It's been so long since I've used a 41 I had completely forgotten about that!

But... If I have FC? assigned to an un-shifted key, say [TAN], then it's

HP-41: TAN Shift 0 0 Shift GTO Shift Σ+
8 keystrokes

and before anyone decries this a foul or cheating, recall that the entire point of key assignments was to reduce keystrokes, so if this were being done often (which almost certainly it isn't) the assignment would save 5 keystrokes every time.

As it seems this thread has devolved to which is more key-efficient, and the 58/59 series don't support non-program key assignments (he thinks...), I have to say the 41C wins again. YMMV.

[Gene]

Using synthetic programming, I think you can assign the entire instruction to a key.

[rprosperi]

(12-21-2017 07:37 PM)Gene Wrote:  Using synthetic programming, I think you can assign the entire instruction to a key.

I initially didn't think you could include prompting commands (e.g. FC? prompts for which flag (or indirect) to test), but the byte table does include them, so AD 80 1D 81 should do it.

So yeah, 1 keystroke. (sorry, no emoji for mind blown)

[Thomas Okken]

(12-21-2017 08:09 PM)rprosperi Wrote:  (sorry, no emoji for mind blown)

U+1F92F

Probably requires a MyBB update for it to work here.

[Dieter]

(12-14-2017 04:38 AM)Gene Wrote:  I think we found it.

Sure?
Didn't the quote in your initial post say ..."re-using the shift keys four times." ?-)

Dieter

[Thomas Okken]

(12-21-2017 08:56 PM)Dieter Wrote:  

(12-14-2017 04:38 AM)Gene Wrote:  I think we found it.

Sure?
Didn't the quote in your initial post say ..."re-using the shift keys four times." ?-)

"Shift keys" (note the plural) presumably refers to 2nd and INV.

In case you disagree, I'm looking forward to seeing another 11-keystroke instruction, which does involve pressing 2nd four times.