casio fx-5000f

this model looks in many ways like the fx-4000p but it is not programmable in the normal sense. instead it is formula programmable and formula entry.

there are no branches and formulae are entered in terms of variables. when ran, the machine prompts for the values of these variables and then displays the formula calculation result. this is simple to operate and quite effective. although there are several drawbacks to the lack of branches.

the machine has 128 built-in formulae, these are recalled by entering a number (0-127) then pressing fmla. recalling these does not occupy the program memory. indeed, rom formula can be recalled and stored as a program and then edited as required. the 128 rom formula are summarised on a handy reference card that lives in the wallet style case. the rom feature is reminiscent of the 128 rom constants of the fx-992v

the picture here shows the quadratic formula (0 FMLA) and solves for x given a, b, and c. the program does this by straightforward use of the textbook quadratic formula. this can work, but there are at least two problems this way. firstly the quadratic formula as stated is not the most accurate way to calculate the roots. second, and more important, the formula without jumps cannot test for a non-real root and thus causes an "MA Error" just as if a negative square root is taken from the keyboard. this is a bit lame since its not even possible to display a message for this case.

as a normal scientific calculator its pretty good, having a good set of features including 2D statistics, number bases (32bit wordsize) and hyperbolics. fractions are missing. physically its quite good, slim and well made and lives in a fold over wallet.