Detron's Calculator Experience, or even more proof I am a nerd

[detron]

I prefer scientific calculators to financial ones, but I do love using the Time Value of Money (TVM) calculations to do mortgage estimates and see how changing the variables effect the solution.
the HP 12C is a great calculator, the the HP 10bII+ has quite a few more functions.

[Max Stone]

Nice one Detron! Nothing beats a financial HP calculator. 

I just with those PMT values were lower when calculating TVM values. 

[detron]

Nice one Detron! Nothing beats a financial HP calculator. 

I just with those PMT values were lower when calculating TVM values. 

I wish this was RPN, but not the end of the world.

[detron]

I was very excited to get this one in the collection.  nice to have the box and all paperwork.

an HP 28S.















this serial number indicates that this particular calculator was made in 1990 (around the 49th week)





the HP 28S was released 1 year after the 28C.  the 28C had only 2k or RAM which was unable to allow the calculator to actually function properly.  they updated the RAM to 32k which was more than sufficient, even though in today's world it sounds tiny.

the 28C was the first calculator with a CAS (Computer Algebra System), but the 28S was the first one with a CAS and enough RAM to put in decent size problems.
the clamshell design allowed for more keys including direct access to the alphabet keys.
this is an RPN calculator.

Original MSRP was $235  (over $500 in 2019 money)

the 28S does include a solver that allows you to enter equations with one or more variables, and solve for any variable.

[detron]

99 cent find

found this at a thrift store for 99 cents!



HP 10b.  a financial calculator that is actually pretty nice.  I really like the looks of this one

[Max Stone]

Great one Detron! (28S) We’ll never see the likes of these again, so it’s great to appreciate what these represented 30 years ago...and that they still work today. 

[detron]

Great one Detron! (28S) We’ll never see the likes of these again, so it’s great to appreciate what these represented 30 years ago...and that they still work today. 

it is an example of the power HP put into devices back when they made amazing calculators

[Don Pablo]

it is an example of the power HP put into devices back when they made amazing calculators

And today, they're still similar, performance-wise.

[detron]

pickup all three of these at a single thrift store today







I paid $10 for all three

[detron]

Got an HP 18C with Manual in the mail today.

[gerleatherberman]

pickup all three of these at a single thrift store today







I paid $10 for all three

Awesome Panasonic and Canon. 

Those lighted displays always make me happy. 

[Max Stone]

Great finds detron. I wish there were thrift shops like you get in the US where I live. 

VFD technology is quite amazing. The vacuum fluorescent display is effectively a tiny cathode ray tube like an old TV. You still see some around on control equipment, but largely replaced by LCD and OLED technology. 

[detron]

for anyone who cares to watch presentations from the HHC (HP Handheld Computers) conferences from 2010 through 2018

https://www.youtube.com/user/hpcalcorg/videos

[Max Stone]

Thanks Detron. 

[detron]

Thanks Detron. 

I had no idea that this was a thing.  happy I stumbled upon it

[detron]

Since I have 6 HP 12C calculators   

I seem to play with them a lot.  My version of a "Hello World" program for programmable calculators is Heron's Formula.
I decided to do this on my HP 12C for fun and a learning process of the keystroke programming.

the user stores the 3 sides of a triangle in the registers 1,2,3 and then presses R/S to calculate the area of that triangle.

the program is

f P/R
RCL 1
RCL 2
+
RCL 3
+
STO 5
2
/
STO 4
RCL 1
-
STO 7
RCL 4
RCL 2
-
STO 8
RCL 4
RCL 3
-
STO 9
RCL 8
X
RCL 7
X
RCL 4
X
g SQROOT
STO 6
g GTO 00
f P/R


after entering your sides in 1,2, and 3 and running the program, the area is displayed on the screen.
any of the following can be recalled and used as needed.

RCL 1 = side 1
RCL 2 = side 2
RCL 3 = side 3
RCL 4 = semi-perimeter
RCL 5 = perimeter
RCL 6 = area of the triangle
RCL 7 = semi-perimeter - side 1
RCL 8 = semi-perimeter - side 2
RCL 9 = semi-perimeter - side 3

I know this is not anything special, but it is enough to excite me and keep me playing with my wonderful calculators.

[Max Stone]

Looks like a good program to try out - thanks Detron! 

[detron]

Looks like a good program to try out - thanks Detron! 

thank you.

I am sure you know, but SQROOT means the symbol.  I was just too lazy to make the proper symbol for the write up.

I prefer Scientific over financial calculators, but man, the 12C is impressive!

[gerleatherberman]

Since I have 6 HP 12C calculators   

I seem to play with them a lot.  My version of a "Hello World" program for programmable calculators is Heron's Formula.
I decided to do this on my HP 12C for fun and a learning process of the keystroke programming.

the user stores the 3 sides of a triangle in the registers 1,2,3 and then presses R/S to calculate the area of that triangle.

the program is

f P/R
RCL 1
RCL 2
+
RCL 3
+
STO 5
2
/
STO 4
RCL 1
-
STO 7
RCL 4
RCL 2
-
STO 8
RCL 4
RCL 3
-
STO 9
RCL 8
X
RCL 7
X
RCL 4
X
g √
STO 6
g GTO 00
f P/R


after entering your sides in 1,2, and 3 and running the program, the area is displayed on the screen.
any of the following can be recalled and used as needed.

RCL 1 = side 1
RCL 2 = side 2
RCL 3 = side 3
RCL 4 = semi-perimeter
RCL 5 = perimeter
RCL 6 = area of the triangle
RCL 7 = semi-perimeter - side 1
RCL 8 = semi-perimeter - side 2
RCL 9 = semi-perimeter - side 3

I know this is not anything special, but it is enough to excite me and keep me playing with my wonderful calculators.

Very cool. Thanks for sharing that.

Hope you don't mind, but I √'ed it for you.

[detron]

Very cool. Thanks for sharing that.

Hope you don't mind, but I √'ed it for you.

I appreciate it actually.  thank you

[gerleatherberman]

I appreciate it actually.  thank you

[detron]

One of my students gave me this last night

[Max Stone]

Nice detron. Looks like an APF mark 40 calculator. Great gift. 

[gerleatherberman]

That is very nice! Gotta love a bright red display.

[detron]

Nice detron. Looks like an APF mark 40 calculator. Great gift. 

thank you.  I was wondering what the "real" version was.  I had figured out the APF portion (who went bankrupt in 1983) but not the model number before being rebranded

[detron]

That is very nice! Gotta love a bright red display.

it is pretty

[Max Stone]

thank you.  I was wondering what the "real" version was.  I had figured out the APF portion (who went bankrupt in 1983) but not the model number before being rebranded

I think it was private label by a Japanese factory. A lot were using the white/blue key combo. You will need to take a look inside at the chips to allow further research. Possibly Canon or Sharp.

[detron]

I think it was private label by a Japanese factory. A lot were using the white/blue key combo. You will need to take a look inside at the chips to allow further research. Possibly Canon or Sharp.

hmm,  I might open it and take some photos.  but it will be when I get done with my degree.  so little free time right now.

[Max Stone]

  good priorities. 

[detron]

good priorities. 

I try,  but is is soo hard when i have a full time job, teach a class once a week, have a family, etc, etc