Thread: Memory teaser

Originally Posted by Stustoys

Hi Avery,
Thanks for that, its sort of coming back to me now that you say it. I'm pretty sure its a scientific calculator, certainly no printer.
They were programmable though right?
You could enter the formula as a program and then just key the variables each time instead of the whole formula?
Would be 20+ years since I used it for real.

Stuart

Yes Stuart,

That is exactly how they worked.

It was running through the procedure once whilst recording it and then entering the variables time after time.

I don't think I have entered in a program on my 12C for probably 20 years although I use it daily.

Thanks Avery,
I dig it out next time I am around there and have a play.

Stuart

The HP-41CV had 4 removable modules with packaged programs or DIY storage, an auxiliary card reader ("cards" about 10mm x 50mm magnetic) for storing DIY programs, and a printer (thermal I think) with paper tape. Also used standard batteries, although a scarce size (N, I think), instead of proprietary battery pack as in the -35 and -45.

Programming was second cousin to assembly language, more or less. On one occasion, long before spreadsheets and PCs were available, I wrote a cyclic program for an engineering project. Started the calculator and went to lunch. Came back to a deskful of tape for processing.

Can you do 3.1415926 x 3.1415926 in your head? or 25.4 x 25.4?

Cheers,
Joe

be careful stu, im 34 , been looking at all day and im about to have a stroke.

Originally Posted by joe greiner

The HP-41CV had 4 removable modules with packaged programs or DIY storage, an auxiliary card reader ("cards" about 10mm x 50mm magnetic) for storing DIY programs, and a printer (thermal I think) with paper tape. Also used standard batteries, although a scarce size (N, I think), instead of proprietary battery pack as in the -35 and -45.

Programming was second cousin to assembly language, more or less. On one occasion, long before spreadsheets and PCs were available, I wrote a cyclic program for an engineering project. Started the calculator and went to lunch. Came back to a deskful of tape for processing.

Can you do 3.1415926 x 3.1415926 in your head? or 25.4 x 25.4?

Cheers,
Joe

I am only just remembering the HP nomenclature.

I worked for HP in the 70s and 80s and little bits of info like this just bring back memories.

The 41c was a substantial weapon. A calculator with peripherals, it probably had 4k of 4 bit memory or something like that. Those were the days when a programmer had to fit everything into 16kbytes or get out.

Originally Posted by Avery

I am only just remembering the HP nomenclature.

I worked for HP in the 70s and 80s and little bits of info like this just bring back memories.

The 41c was a substantial weapon. A calculator with peripherals, it probably had 4k of 4 bit memory or something like that. Those were the days when a programmer had to fit everything into 16kbytes or get out.

The HP41 still lives - see App Store - i41CX+ RPN Calculator with Printer

It's my favorite app.

BTW I still have a working original, I used to run a nuclear reactor model on it! but the iphone emulator is much faster.

Originally Posted by Dave J

I have one here that is white plastic and in a cardboard box. It's from my father in law who was a draftsman for the mines.
It has been years since I looked at it, but from memory my one was a sliding rule for drawing to scale, but I am not 100% on that.
I also got his old drafting board with it and many other drawing pieces.

Dave

gee...we are showing our age...cos I have one too..yep also a white plastic one in a bluish leather looking case

Avery , you probably mean the HP41 series. I have the HP41CV with a bundle of application packs, HP-IL interface and cassette deck, These calculators have keypad overlays for the specific application packs. It's really a mini handheld computer.

Originally Posted by Avery

Both my calculators are pocket versions. The 12C is a financial calculator and the other, which I cannot find, is a scientific calculator, I think now an HP45.. Both use RPN. HP did make some desktop calculators, the 98xx series some with printers built in. All of HPs calculators used RPN . It was Bill Hewlett's baby.

RPN really has nothing to do with the programability, it is the method of doing the calculations. The calculators used a stack of memory registers the lower two being the x and y registers. The x was the register that held the display contents and the y was the one above it.

RPN calculators do not have a "=" key.

They do have an "enter" key.

to multiply 2 x 3 the sequence is "2" "enter" (the enter shifts the 2 from the x to the y register) then "3" then the function key, in this case the multply key. The result appears in the display (x register). A subsequent calculation requires the number to be entered and a function key pressed. This method , for a sequential calculation, means less keystrokes and the interim results being shifted up through the registers for later retrieval.

It sounds complex but the actual use is amazingly simple.

I still use my fingers and toes.

"you must provide the location of the decimal point by feeling the magnitude."
That was why I preferred the log tables over the guessing stick in the days of old when calculators weren't invented.

Originally Posted by eskimo

gee...we are showing our age...cos I have one too..yep also a white plastic one in a bluish leather looking case

Yeah, Still got my 13" slide rule ..a plastic coat on bamboo and you could slip it out and turn it over for logs. Got a circular one as well and a HP 12C...

Still use the circular one for conversions ..metric shyte back to real 'imperal' stuff...

A couple of years ago I was given A TAG "Pilots"watch which incorporates a slide rule in the bezel.

It allows you to calculate fuel burn and time to run.

Wish I knew how to use it (even though I have no use for it beyond telling the time) as I can't find any instructions on the Web.