Is this right? 33s ALG mode quirk


Hello all.

Am I right in my discovery that the ALG mode of the 33s has an entry system that is NOT left to right but rather, the entry system identical to the old TI SR-56, SR-52 method -- i.e sin(30+4/3) is entered as:


Note that the sine function comes after the parentheses are closed.

I thought the ALG mode on the 33s was a left-to-right entry.

Edited: 16 Mar 2012, 3:15 a.m.


This way, you have a chance to see what the argument is. I very much prefer it to the VPON (visually perfect but otherwise nonsense) entry method of the Casio-like HPs.

Edited: 16 Mar 2012, 3:37 a.m.


If I'm not mistaken the 35S has changed this so that algebraic mode looks much more like equation mode while the 33s follows the traditional AOS (as opposed to EOS) system.


I think that the "equation" style is not good, and the "first, calculate argument; then calculate function" style is better. Of course, I prefer:


which is closer to the "first, calculate argument; then..." style.


It isn't a quirk. It is very purposefully designed. The 33s has three entry systems:

1. The ALG mode, which is infix for operators and y^x, and postfix for functions (essentially 1970s algebraic) but with the very interesting and useful upper line showing the expression compiled!

The second system is "left to right" and is the equation editor.

The third is of course RPN operating on the stack.

Note that in ALG mode there is a stack of sorts: variables x1 through x4 which can be recalled with the Rdown button. Read the manual to understand their use.

Also note that Lastx can be used in Algebraic to do chain calculations between two running calculations. (Very early ROMs were somewhat different and I can't remember where I filed my write-up of that!).

I very much like the design of this machine. I wish that rather than retiring it, they simply perfected it. If it had the equation editing capability of the 35s, and all other minor bugs cleaned up (they already cleaned up the major ones) it would be terrific. Compared to the 35s, it has much better direct keyboard capability and it has a much better implementation of Rectangular to Polar and of BASE arithmetic.

The 35s has a few "special" ideas such as the vector business, but at the expense of the good stuff.

Edited: 16 Mar 2012, 10:28 a.m.


Hello all. After trying these ideas and putting them into perspective, the three entry systems do have their benefits. I am very impressed with the error recovery of the 33s' ALG entry. And, with that in mind plus I'm already accustomed to TI's original AOS entry, the 33s approach not only builds upon and picks up where AOS left off, the 33s fixes the error-recovery method of TI's SR-56. And it's cleaner with the enhancement of actually seeing the effects of the recovery right there.

Although I still an partial to RPN and RPL, I find the error-recovery in the ALG entry a beneficial compromise in lieu of the 35s functionality of addressing stack registers in EQN mode. It is helpful that in ALG mode, I can access the ALG stack too.


The 33s ALG even has the "arithmetic with constant" feature which I think is identical to the old SR Ti machines (I haven't had one in my hands since the early 80s).

4+3 = 7
push equals again and you get:
7+3 = 10


Edited: 16 Mar 2012, 12:47 p.m.

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