Amortize specific period ranges

[Dave Britten]

I just got a Sharp EL-738. It does arbitrary-range amortization like the others, and it's reasonably quick, doing 360 periods in about 2 seconds.

Overall, I really like it. The keyboard is excellent. The keys are nice and soft, but with just enough tactile feedback and noise, and the numeric and operator keys are nice and large (11 mm by 8 mm, with 3.5 mm spacing). The two-key rollover is great, and you can type extremely quickly. I haven't seen it miss a keystroke yet.

It's also got scientific functions (trig, logs, exponents, hyperbolics, and basic probability and combinatorics), plus statistics with 6 different regression models and up to 50 data pairs. No degrees/hours-minutes-seconds conversion, unfortunately, but it does compute days between dates, dates n days from a given date, and days of the week.

Usage is very much like the TI BA II Plus, with the whole worksheet setup, which is nice if you need to quickly get up to speed with a function you've never used, or which you use infrequently. You can easily edit, insert, and delete both cash flow and statistical data after it's been entered. The manual is pretty good, and has several examples.

My main gripe is that read-only worksheet values can't be directly used in calculations. So if I amortize a payment range, and want to accumulate the interest values in a storage register, I can't calculate with that output directly. There's a workaround: when you display a value in a given worksheet, it's automatically stored in ANS. Just press ON/C to exit the worksheet, and you can then use ANS to work with the last displayed value. The downside is that this involves a few extra keystrokes, and the values for P1 and P2 will reset to 1 when you go back into the amort worksheet. Not a deal-breaker, though, and not nearly as big a flaw as I've found in other models (like that awful TI keyboard). I'd rather have a few extra steps for this occasionally used function than missed keystrokes everywhere. And if I'm doing that for more than just a couple groups of payments, I'm probably doing it with 1-2-3 on my 200LX anyway.

I might have to check out some of the Sharp scientifics and see how they compare.