CASIO fx-5500 Scientific Calculator: The 1st "C.A.S." pocket calculator?

[jebem]

"Factoring made easy" by Casio in 1986!

Was this CASIO fx-5500 the first calculator in the market able to do symbolic calculus (formula manipulation) although in a very limited format, otherwise known as C.A.S. these days?

This machine belongs to another local collector that kindly allowed me to have for some time for testing.




This is a handy little machine, almost of the same size and form as the HP Voyager series, although featuring totally different capabilities and operation philosophy.




Main features, based on the user manual:

• 24 digit LCD with 5x7 dot matrix alphanumeric capability.
• Analog contrast adjustment.
• Constant Memory.
• Power supply: 2xCR2032
• True algebraic logic operation. Replay for easy editing
• Display: 10 digits mantissa and 2 digits exponent.
• Internal: 12 digits mantissa and 2 digits exponent.
• Each result is rounded to 10 digits for display
• Stack sizes:
  - Manual operations: Numeric 8 levels, command 20 levels.
  - Formula manipulation: Numeric 15 levels, command 20 levels.
• Input buffer size for each entry: 79 steps storage area for numbers and commands
• Memories:
  - 3 x Formula memories (I, II, III). Each up to 79 steps.
  - 12 x Register memories (A to L)
• 34 functions
• Symbolic calculus (Formula manipulation):
  - Expansion
  - Factoring
  - Simplify
• Solver (one unknown quadratic and linear, three unknown linear)
  

Forensics test: arcsin (arccos (arctan (tan (cos (sin (9) ) ) ) ) )
Result: 9.000007164 the same as for the Casio fx-730P among others.
Doing (9-Ans) *1000000 to find additional internal digits gives just 7.164.




Using some expressions from the user manual examples to test the symbolic manipulation capability.
Well, it is not a powerful manipulation and we can't even consider it a full C.A.S. system, but in 1986 it was something rare, if not unique, to see on a pocket calculator.

Simplify 5X^2 + 7X - 6 - 3X^2 + 2X + 9
Took about 2 seconds to find this result: 2X^2 +9X + 3




Just for fun, tried to Expand (X + 3)^5
It took about 8 seconds to find this result: X^5 + 15X^4 + 90X^3 + 270X^2 + 405X + 243