The Citizen SRP-320G is a graphing calculator. Looks nice and unique, but upon closer examination you may find that it is not really unique and not as nice as you might expect. You see, this machine turns out to be no more than an imperfect clone of the Casio fx-6300G. Why imperfect? The Casio fx-6300G didn't have buggy firmware, but that, unfortunately, is the case with the SRP-320G. One of the first things I try on a new calculator is Mike Sebastian's calculator forensics algorithm; on a formula entry model like the SRP-320G, I'd enter sin^-1 cos^-1 tan^-1 tan cos sin 9-9 to compute the result. Except that it computed the wrong result. Closer examination revealed that the calculator executed the last sin^-1 operation in Radians mode despite the fact that it was in Degrees mode. I was able to get the correct result when I broke up my expression into two lines: cos^-1 tan^-1 tan cos sin 9 followed by sin^-1 Ans-9. Very sloppy indeed.

Equally sloppy is the manual. At first, my heart was filled with joy: finally, a calculator with a decent-sized manual! It sure is a thick book, reminiscent of the manuals you got with early HP calculators. But when I looked more closely, I found the reason on the title page:

CITIZEN™ Scientific Calculator SRP-320G Instruction Manual Bedienungsanleltung Manuale di istruzioni Manual de instrucciones Manual de instruçőnes Рук оводство по эксплуатации Mode d'emploi

It's easy to make a brick out of a manual if you publish it in seven languages.

By the way, the typos aren't mine. I know how to spell Bedienungsanleitung. And it gets worse. Inside the manual, mathematical expressions are often unreadable. Keyboard symbols and graphics overlap text. The only good thing I can say about the book is that it appears someone ran it through a spell checker: spelling mistakes and grammatical errors that are so common to Far Eastern manuals are missing from this volume. But that is no excuse for the incredibly sloppy, substandard typesetting job!

The program below I wrote originally for a Casio programmable. It runs identically on the SRP-320G. It demonstrates the calculator's capabilities by accurately computing the logarithm of the Gamma function using the Lanczos-approximation. A conditional expression is used to compute the correct result for negative arguments (the machine must be in radians mode):

Ans→X:
Abs X→Z:
ln (2.506628275+6.3E-10+(225.5255846+1.9E-8)÷Z-
(268.2959738+4.1E-8)÷(Z+1)+(80.90308069+3.5E-9)÷(Z+2)-
(5.007578639+7.1E-10)÷(Z+3)+(1.146848954E-2+3.5E-12)÷(Z+4))+
(Z-.5)ln (Z+4.65)-Z-4.65→G:
X<0⇒ln (-π÷X÷sin πX)-G→G:G