(01-20-2015 09:04 AM)Bruno Wrote:  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.

(01-20-2015 01:30 PM)rprosperi Wrote:  ... why not just publish the list of links where you found them, then there is no need to re-host them elsewhere? I assume they are from public sources?

(01-20-2015 01:30 PM)rprosperi Wrote:  First, your English seems pretty clear to me, so no need to apologize for that.

(01-20-2015 01:30 PM)rprosperi Wrote:  Since you said that you downloaded all these patents, why not just publish the list of links where you found them, then there is no need to re-host them elsewhere? I assume they are from public sources?

(01-20-2015 01:30 PM)rprosperi Wrote:  And thanks for digging these out and sharing. Though tedious to wade through in detail due to the traditionally required legalese and structure, software patents are usually quite interesting to understand the core vision the author(s) (presumably much is from Bill Wickes here) had and see how the end product adhered-to or deviated-from the core concepts.

(01-20-2015 09:04 AM)Bruno Wrote:  - 5,089,980 : Double keystroke fraction entry and interface method

(01-20-2015 03:06 PM)Claudio L. Wrote:  

(01-20-2015 09:04 AM)Bruno Wrote:  - 5,089,980 : Double keystroke fraction entry and interface method

Interesting. So if let's say newRPL or the 43S projects use the dot to enter fractions HP would have a patent claim?

(01-20-2015 03:10 PM)walter b Wrote:  

(01-20-2015 03:06 PM)Claudio L. Wrote:  Interesting. So if let's say newRPL or the 43S projects use the dot to enter fractions HP would have a patent claim?

Don't be afraid. Patents don't live forever. In fact, they die after 18 years in Europe, IIRC. I'd guess US American rules are similar. After that lifetime, it's simply state of the art.

d:-)

(01-20-2015 03:06 PM)Claudio L. Wrote:  

(01-20-2015 09:04 AM)Bruno Wrote:  - 5,089,980 : Double keystroke fraction entry and interface method

Interesting. So if let's say newRPL or the 43S projects use the dot to enter fractions HP would have a patent claim?
I guess we need to use a different key then, but it is natural to use the dot.

Claudio

(01-21-2015 08:52 AM)Bruno Wrote:  To Mark : Thank you