HP Patents

[Bruno]

Hi all,

always in the hope to find more technical documents about RPL based calculators (HP-18 to HP50),
I've find some very interesting HP Patents (see the list below).
Is there anyone who maintain a list of all patents about RPL ?
Could anyone help me to reference and download all of them ?

I think it will be a good idea to add them to the HPMuseum DVD

Here is the list of all patents I've found and downloaded (pdf), anyone who can host them are welcome

HP28C Patents: (Number, Title)

- 4,852,057 : Algebraic expression method and implementation for an electronic data processing apparatus
- 4,845,652 : Generic equation solver interface for solving mathematical equations
- 4,868,745 : Data processing system and method for the direct and indirect execution of uniformly structured object types
- 4,821,228 : Method and apparatus for computation stack recovery in a calculator
- 4,885,714 : Calculator having a user-accessible object stack for the uniform application of mathematical functions and logical operations to a multiplicity of object types

HP48SX Patents:

- 5,258,748 : Accessing and selecting multiple key functions with minimum keystrokes
- 5,260,886 : Default denominator for fraction entry and display
- 5,089,980 : Double keystroke fraction entry and interface method
- 5,075,792 : Low power optical transceiver for portable computing devices
- 5,216,627 : Method and apparatus for computing with terms having units
- 5,067,102 : Method and apparatus for displaying and editing mathematical expressions in textbook format
- 5,175,700 : Method and apparatus for solving multiple equations
- 5,155,697 : Most precise fraction display method
- 5,128,887 : Numerical accuracy indicator for rounded numeric value display method
- 5,065,356 : Shared use of keyboard and memory lines

Thanks, and sorry for my poor english.