casio fx-85m

it is ideal for general use. its solar powered without batteries, the rubberised keys work well and have a tactile feel and the display is clear, but only 8 digits. although ordinary in most respects, you would be hard pressed to find a cheap value-for-money unit today that is built to the same standards. consider what has become of the ti30 line, the ti30xiib. cheap, yes, but nasty also.

compared to the fx-85v it lacks some features. the 85v is a bit more advanced, having 2D stats, regression, k-memories, more buttons, a delete key and rather nice 8+2 display. the 85v model must be the updated version and this the older one.

one of the problems with pure solar machines like this one, is that it often powers up in a random state and unable to calculate. this is remedied by selecting mode 0 and mode 9, ie setting it back to normality. occasionally, the memory will also contain garbage or error. the pure solar sharp el-545 has this problem too. it is remedied there by a ca button that acts to reset the machine.