I received an eBay-purchased original LED Texas Instruments TI-30 today -- just like the one I got for Christmas in 1977 or 1978, and whose circuitry I accidentally fried a few years later.

Aesthetically, it's quite pleasing. I'd forgotten how light and wide it was -- bigger than an HP-35, HP41, or HP-34C. (The latter looked to me like an *ueber* TI-30 when I first saw it.)

The TI-30's respectable level of quality, however, does not match that of HP's much-costlier models of the era.

__GOOD STUFF:__

- No-nonsense 40-key grid with clear legends on a backplate with eye-soothing gold and brown colors. Much more handsome than the HP-35!
- (8-digit) display angled for easy viewing at desk.
- Degree/radian/grad mode with annunciators. (The HP-35 didn't have the modes; the HP-34C didn't have annunciators.)
- Logical functional groupings. Here's something I noticed 30 years ago: Keys inside the light-brown background are for data entry. Keys inside the dark-brown background are for arithmetic (/, *, -, +, =, K [constant-term]). Keys with blue legends can be used with the blue-legend "INV" key.

__SHORTCOMINGS:__

- Stiff keys that suffer from non-response and bounce (perhaps worsening over time).
- Accuracy not fully justified by its three guard digits. Example: [1][INV][ln
*x*] = 2.7182818 is displayed. Subtract 2.71 and multiply by 100: .82818301 is displayed; .82818284 are the correct digits. Why compute__three__extra digits that are not quite accurate? - Lack of rigor in display format: pi / 10 displays .31415927. pi / 1 [EE]1 displays "3.1416 00" (3.1416 x 10
^{0}). Now, just__try__to get out of scientific-format display mode! Move the decimal place repeatedly to the left using [INV][EE], and watch the mantissa be obliterated, as significant digits fall into the "bit bucket" until "0 06" ( 0 x 10^{6}) is displayed.__Not__good. Perhaps TI's youthful customers didn't care, but HP's professional customers certainly would have.

I googled "ti-30" and found several dedicated pages, notably the somewhat-opinionated TI-30 Wikipedia page that could use some improvement. Here are several quotes:

Quote:

It could do just about all the log and trig functions of an HP-35

Actually, it does __everything__ the (five years older) HP-35 does, and then some -- e.g, x[super]2[/super], 10^{x}, y^{1/x}, % -- but with slightly lower computational accuracy.

Quote:

It pioneered algebraic notation with precedence and parentheses which is now favored by all but the most die-hard RPN fanatics, and takes significantly more logic to implement. A user could type in (2 + 2) + 3 * 3 = and get the correct result, where an HP user would need to strategize and do 2 enter 2 + 3 enter 3 * +.

Hmm, how about "2 ENTER + 3 ENTER * +" for a 'strategy' that obtains the correct answer of 13 in three fewer keystrokes, while showing the other intermediate result? Maybe not the best example...

Here are several other useful links:

-- KS

*Edited: 18 Jan 2007, 11:46 p.m. after one or more responses were posted*