|Re: 20b - Observations|
Message #2 Posted by Gene Wright on 15 July 2009, 10:50 a.m.,
in response to message #1 by Thomas Radtke
1) Yes, the 20b uses a "command line" approach as an input to the stack. Your addition example points out the effect quite well. Another result can be that if you have a stack full of 4 values and begin typing another number, if you press ON/CE, you still have all 4 values. On a "true RPN" machine, you would have lost the value in T. On the 20b, T is lost only if you do something with the value you are keying it. ON/CE is an "abort" button.
2) The % operation works as "RPN" does.
So, a bit of a hybrid, probably because it reuses the RPL approach to inputs on the stack.
3) If you're referring to an apparently blank display, then yes, this is a non-normalized number aka error result. I know HP is aware of this. Of course, a blank display should never be returned to the user, so this is a bug.
What ROM revision is on your 20b?