Sharp EL-5030 - powerful but unknown

[Vincent Weber]

I recently bought on eBay this little wonder.
I am surprised it had so little success.
This is a direct competitor, probably released circa 1987, to the Casio fx-4000p (1985), but with 3 times the memory, and a very original formula programming model that accepts up to 99 named formulas (compared to the simple prog 0...9 slots on the Casio); up to 10 internal subroutines per formula (as opposed to external on Casio, which severly restricts the number of subroutines); looping (not with labels and gotos, but with more concise loop start / loop end constructs); powerful and elegant conditionals that emulates IF...THEN...ELSE with -Y->[] and -N->[], avoiding the use of multiple labels and gotos. And last but not least, I believe this is the only non-graphing alphanumerical Sharp calculator (not BASIC pocket computer) to feature indirect register addressing, with dedicated arrays that do not share the same A...Z space with normal variables (as opposed to the Casio). This is therefore a Turing-complete machine.

The model also has its limitations, not found on Casio: conditionals cannot be nested; subroutines can't feature loops nor conditionals; and each formula is limited to 160 characters, which seems severe but actually not so much, since the tokenization is quite efficient: Altough you can insert a space between 2 steps for clarity, it is actually not mandatory since the syntax is unambiguous, so you can save a lot of memory (as opposed to the Casio mandatory ":" separator which costs one step every time).

All in all this is a marvelous, powerful little calculator, and I wonder why the somewhat lesser fx-4000p is so well known, whereas this one is not known at all.

Any idea ?

Cheers,

Vincent