## Re: Cheap Bit Banger's Calculator

Expand Messages
• All this talk of RPN is making me miss my HP-97 of many, many years ago... Cory - WA3UVV
Message 1 of 13 , Dec 6, 2012
All this talk of RPN is making me miss my HP-97 of many, many years ago...

Cory - WA3UVV

• My dad got me my first calculator for school when I was in 11th grade for Christmas, since an advanced graphing calculator was required for AP Calculus. He got
Message 2 of 13 , Dec 6, 2012
My dad got me my first calculator for school when I was in 11th grade for Christmas, since an advanced graphing calculator was required for AP Calculus. He got me, not the TI-89 Titanium that everyone else had, but rather the HP-49g+. I hate to say it, but I was very disappointed that I didn't get the mainstream calculator. My dad ended up agreeing that since the school pushed for TIs that he'd get me a TI.

It wasn't until my summer before my senior year of high school that I ended up really using the 49g+. The buttons promptly started breaking, as was the "feature" with said calculator. One of my dad's friends gave me his original college calculator, an HP-45 (HP's second scientific model), and after replacing the batteries, I was able to use it quite a bit. That got me really started with enjoying the benefits of RPN.

However, it still wasn't until I was into my freshman year of college that I really saw the benefits of RPN. My absolute favorite demonstration is parallel resistance calculations. For most algebraic calculators, the method is 1/(1/a+1/b), where a and b are the two resistor values to be paralleled, and sometimes people even insert more parenthesis than need be. On the RPN, it's just a [inv] b [inv] + [inv]. Far fewer keystrokes! One of my professors even made a joke (hardly a joke, really) that the students who finish first on exams must all have RPN calculators.

Just recently I got an HP-48g to replace my 50g, which replaced the 49g+. The 50g is nice, but who needs all of those features for EE? Certainly not I. The buttons on the 48g are infinitely better anyways.

On my Android, RealCalc is a favorite, as it has a nice RPN mode. Takes a little getting used to from the 48g world, as the entry vs. x register is not as well defined in RealCalc as it is in the HP world. Entry automatically becomes x, and everything else is pushed up. In HP land, the entry is its own temporary register, which I prefer, likely because I'm used to it. Maybe I should try out a 48 emulator on Android.

One day, I'll own an HP-9100A...

Kyle
• ... Wow, very cool. Most people opted for the handheld version, the 67. I have two 97s (I have a biggish collection of HP calculators) and would be willing to
Message 3 of 13 , Dec 6, 2012
On 12/06/2012 09:28 AM, Burning Image wrote:
> All this talk of RPN is making me miss my HP-97 of many, many years ago...

Wow, very cool. Most people opted for the handheld version, the 67.

I have two 97s (I have a biggish collection of HP calculators) and
would be willing to part with one for the right deal. I can bring it
with me when I come to your place this weekend. Let me know if you
wanna talk turkey.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
• ... I still have my first HP, the HP28s (or c but I think it s the s). I won t let it go (though the battery compartment is broke, a common flaw on the 28).
Message 4 of 13 , Dec 6, 2012
On 12/06/2012 11:48 AM, Dave McGuire wrote:
> On 12/06/2012 09:28 AM, Burning Image wrote:
> > All this talk of RPN is making me miss my HP-97 of many, many years ago...
>
> Wow, very cool. Most people opted for the handheld version, the 67.
>
> I have two 97s (I have a biggish collection of HP calculators) and
> would be willing to part with one for the right deal. I can bring it
> with me when I come to your place this weekend. Let me know if you
> wanna talk turkey.

I still have my first HP, the HP28s (or c but I think it's the s).
I won't let it go (though the battery compartment is broke, a common
flaw on the 28). The 28 can do 'normal math' but RPN is so much easier

That said, I always have my phone and my tablets around so I just use
them with droid48 (x48). On my Linux box I have a command line version
of a rpl calculator (based on the hp28). I downloaded it from
comp.sources.misc and I've had it ever since (C portable code good!).

--
Linux Home Automation Neil Cherry ncherry@...
http://www.linuxha.com/ Main site
http://linuxha.blogspot.com/ My HA Blog
Author of: Linux Smart Homes For Dummies
• ... I have a 28S as well. It was my daily driver for programming until about a month ago when one of its keys died. I haven t gotten around to attempting
Message 5 of 13 , Dec 6, 2012
On 12/06/2012 01:01 PM, Neil Cherry wrote:
> I still have my first HP, the HP28s (or c but I think it's the s).
> I won't let it go (though the battery compartment is broke, a common
> flaw on the 28). The 28 can do 'normal math' but RPN is so much easier

I have a 28S as well. It was my daily driver for programming until
about a month ago when one of its keys died. I haven't gotten around to
attempting repair yet. I was heartbroken; that's such a fantastic
calculator for programming use!

> That said, I always have my phone and my tablets around so I just use
> them with droid48 (x48). On my Linux box I have a command line version
> of a rpl calculator (based on the hp28). I downloaded it from
> comp.sources.misc and I've had it ever since (C portable code good!).

WHat's the name of that rpl command line calculator? I'd love to have
that.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
• ... ROFL! Yes I love my HPs for parallel resistance calculations. FAR easier and faster. ... My favorite all-around calculator for lab use is the HP-41, when
Message 6 of 13 , Dec 6, 2012
On 12/06/2012 11:44 AM, Kyle Owen wrote:
> However, it still wasn't until I was into my freshman year of college
> that I really saw the benefits of RPN. My absolute favorite
> demonstration is parallel resistance calculations. For most algebraic
> calculators, the method is 1/(1/a+1/b), where a and b are the two
> resistor values to be paralleled, and sometimes people even insert more
> parenthesis than need be. On the RPN, it's just a [inv] b [inv] + [inv].
> Far fewer keystrokes! One of my professors even made a joke (hardly a
> joke, really) that the students who finish first on exams must all have
> RPN calculators.

ROFL! Yes I love my HPs for parallel resistance calculations. FAR
easier and faster.

> Just recently I got an HP-48g to replace my 50g, which replaced the
> 49g+. The 50g is nice, but who needs all of those features for EE?
> Certainly not I. The buttons on the 48g are infinitely better anyways.

My favorite all-around calculator for lab use is the HP-41, when I'm
at my desk writing code it is (was, see other email) an HP-28S, and for
everything else I like the HP-48SX.

> One day, I'll own an HP-9100A...

Keep dreamin'.

-Dave

--
Dave McGuire, AK4HZ
New Kensington, PA
• ... It s called rpl, somehow I named it hp28 and I left it that way (it doesn t do everything the HP28 does and it s a little different than the hp48).
Message 7 of 13 , Dec 6, 2012
On 12/06/2012 01:03 PM, Dave McGuire wrote:
> On 12/06/2012 01:01 PM, Neil Cherry wrote:

> > That said, I always have my phone and my tablets around so I just use
> > them with droid48 (x48). On my Linux box I have a command line version
> > of a rpl calculator (based on the hp28). I downloaded it from
> > comp.sources.misc and I've had it ever since (C portable code good!).
>
> WHat's the name of that rpl command line calculator? I'd love to have
> that.

It's called rpl, somehow I named it hp28 and I left it that way (it doesn't
do everything the HP28 does and it's a little different than the hp48).

http://linuxha.com/athome/common/hp28-20121206.tgz

I have a ton of hp28 manuals (including this utility manuals written by a
3rd party). The scripting is nice and the fact that you can access the
OS from the calculator.

--
Linux Home Automation Neil Cherry ncherry@...
http://www.linuxha.com/ Main site
http://linuxha.blogspot.com/ My HA Blog
Author of: Linux Smart Homes For Dummies
Your message has been successfully submitted and would be delivered to recipients shortly.