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HP Forum Archive 13

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HP71B: two questions
Message #1 Posted by Vieira, Luiz C. (Brazil) on 19 July 2003, 5:40 p.m.

Hi, HP71B users;

my turn to ask questions.

I received one e-message mentioning the HP71B's ROM version. How can I know which version is mine? Serial # or some specific command?

I remember that BASIC variables are all set to "0" (empty?) and all definable variables for an specific BASIC environment exist anytime a program "call" their contents. This is not the same with C, where variables not "declared" in a program are taken as "error" if called. Anyway, based on what I saw so far, used variables in the HP71B consume memory space. Is there a way to list varable names already used somehow?

Thanks for any help.

Luiz (Brazil)

Edited: 19 July 2003, 5:41 p.m.

      
Re: HP71B: two questions
Message #2 Posted by Emmanuel, France on 19 July 2003, 5:58 p.m.,
in response to message #1 by Vieira, Luiz C. (Brazil)

VER$ should give you the version of your HP-71B and plugged ROMs. If I remember well...
Yours.
            
Re: HP71B: two questions
Message #3 Posted by Sean McNamee on 19 July 2003, 6:27 p.m.,
in response to message #2 by Emmanuel, France

...and my turn to pay you back ;) Yes, VER$ gives version info, and DELETE ALL deletes the space used by variables. Also, you can DELETE specific vars by name.

                  
Re: HP71B: two questions
Message #4 Posted by Vieira, Luiz C. (Brazil) on 19 July 2003, 6:44 p.m.,
in response to message #3 by Sean McNamee

Hi, Sean;

thank you for the information. I read that DESTROY names and DESTROY ALL would "erase" variable contents. I was not know about DELETE being used the same way.

Now, is there a way to know which variables have their contents changed before "erasing" (deleting, destroying) them? I thought about listing their names. Is it possible?

Thanks again.

Luiz (Brazil)

                        
Re: HP71B: two questions - oops
Message #5 Posted by Sean on 19 July 2003, 6:50 p.m.,
in response to message #4 by Vieira, Luiz C. (Brazil)

Sorry - I meant DESTROY. Not DELETE. I tend to mix both of those as well as PURGE up.... I really have no idea about listing variables, let me find my manual and take a look.... (will post results)

            
Thanks Emmanuel and Sean
Message #6 Posted by Vieira, Luiz C. (Brazil) on 19 July 2003, 6:45 p.m.,
in response to message #2 by Emmanuel, France

Hi, Emmanuel;

thank you. As Sean confirms your answer, you actualy remembered it well.

Best regards.

Luiz (Brazil)

      
Re: HP71B: two questions
Message #7 Posted by Victor Koechli on 19 July 2003, 7:49 p.m.,
in response to message #1 by Vieira, Luiz C. (Brazil)

DESTROY <var> can be used to free the memory used by individual variables, and DESTROY ALL will delete all allocated variables in the current environment.

However, I have not found an obvious way to list the variables currently allocated. You would probably have to consult the Software IDS to find out where this information is stored, and peek it from the HP 71's allocation tables.

Cheers, Victor

            
That's what I was affraid of...
Message #8 Posted by Vieira, Luiz C. (Brazil) on 19 July 2003, 8:13 p.m.,
in response to message #7 by Victor Koechli

Hello, Victor;

I was affraid I'd have to "peek" RAM positions in order to seek for variables. I'm not aware of how is data organized in the HP71's RAM, I believe I'll find this information in the Internal Specs documents, as you mentioned.

I'd be delving into this subject with more "energy" if I had an HP71B, say, eighteen years ago, when I was actualy programming and working with assembly code. But I'll find the time to go further somehow.

Thanks a lot.

Luiz (Brazil)

Edited: 19 July 2003, 9:32 p.m.


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