Known TI models with key bounce issue?

[themaritimeman]

Hi,

Does anybody know if the following TI calculator models do/do not suffer from the key bounce issue?

TI-2550
TI-1250
TI-1450
TI-1265

Thanks!

[Accutron]

Key bounce is endemic to all TI handhelds from the mid-1970s through the early 1980s. Of the models you listed, the only two that I own are the 1250 and 1450, but they both can bounce or miss keystrokes. Other models from that era which I can confirm have bounce problems include the TI-1200, TI-30, TI-51-II, TI-55, TI-57, TI-58, Business Analyst, BA-II, TI-1030, TI-35, TI-30-II and BA-35. The rule of thumb is, if it has the TI logo, it can have bounce problems.

You might have better luck with an older TI machine like the Datamath, which has a Klixon keyboard.

[themaritimeman]

Thanks for the info. The TI-2550 is a direct descendant of the Datamath, so I wonder if that has the Klixon keypad?

[Gene]

Accutron is not far off the mark, but it is a bit of a generalization.

So here's another generalization. :-)

If you go to datamath.org and are looking at the scientific / financial portion of the album:

MOST of the time, the key bounce problems occur on these product lines:

Majestic
The first and later Slimline LCD range
and MOST egregiously, the slanted LCD first generation.

Let me illustrate with a numeric scale, where 10 is awful, nearly give up trying to enter a number and 1 is the what? initial HP 35 keyboard in 1972 ? :-)

Slanted LCD first generation - 9
First and later Slimline LCD - 6
Majestic series - 4

On the other hand, 90+% of these models have always worked just fine for me:

SR series - SR10, 11, 16, 16II, 50, 51, 50A, 51A, 52, 56, 58, 58C, 59. Note the 57 is more a majestic line machine.

My 2 cents. I don't deal with the non-scientific or non-financial models. No 4 bangers for me.

[Maximilian Hohmann]

Hello!

(01-25-2017 05:45 PM)Gene Wrote:  My 2 cents.

I can confirm to 100% what you wrote. Absolutely worst of all is the slanted LCD first generation series. I have not come across a single calculator from this series that is actually usable. The very worst of them is the "Jeppesen Prostar" (you find it in the "Calculators built by Ti" section), an aviation calculator. I have two or three of them in my collection and not one of them can be used to calculate "1+1="... Given that these specialised calculators were quite expensive then, this is really annoying.

[matthiaspaul]

(01-25-2017 06:05 PM)Maximilian Hohmann Wrote:  Absolutely worst of all is the slanted LCD first generation series. [...] The very worst of them is the "Jeppesen Prostar" [...], an aviation calculator. I have two or three of them in my collection and not one of them can be used to calculate "1+1="... Given that these specialised calculators were quite expensive then, this is really annoying.

At some point in time Texas Instruments ran an exchange programme for the whole series at least over here in Germany - you could go to authorized dealers and choose a free replacement calculator from about the same price level - even if the original calculator was long out of warranty. However, for some calculators they didn't have suitable replacement models. I remember that I had to replace my TI-54 by a TI-56, which brought some additional functions, but lacked others for which I had chosen the TI-54 originally...

Greetings,

Matthias