Need advice from Engineers who are also TI users

[Nigel (UK)]

I'm a physics teacher rather than an engineer, but I do own several of these TI calculators. If you like the TI-83+ you'll probably love the TI-86: well out of production but still available on various auction sites. It's got the multi-line display that you like, and a two-line menu on the screen gives access to lots of functions. There is full support for complex numbers (no "complex mode" needed) and it is easy to program, even if you don't want to at the moment.

(The TI-85 has almost exactly the same functionality, but less memory (still plenty if you aren't programming) and a lower-contrast display.)

It will do plenty of unit conversions; what it doesn't have (I think) are unit objects, which the TI-89 and several HP calculators have. Conversions may be all that you need; I think you can define your own if you want to.

The TI-85 and TI-86 feel as though they have been designed for people who are actually going to use them, rather than principally for students.

Nigel (UK)