On Wed, 20 Oct 2010 12:16:23 -0700 (PDT), " email@example.com"
In 1972, I got a 90 on a test instead of a 100 because I wasted time
with my slip stick. So, I went out and spent $200 on an SR-10, four
function plus reciprocal. I remember I had just got a raise from 1.60
all the way to 2.30 so it only took two weeks pay.
You are not the only one, Karl.
Sometime, about 1975,76, or so, I was programming for the bank
processing division of a computer service bureau. One day the manager
of the other half of the company, the non-bank division, asked if I
could look at a program one of the programmers was having trouble
with. Sure, should take just a little while! Right.
The program had to compute something based on the prime interest rate.
If you remember those years, the prime rate began to change twice a
month, then weekly, and for a short time, twice a week. The programmer
was way over his head, and so was I. I worked on the problem for over
a week, using pencil and paper to do the computations, until I finally
figured out how to handle all the rate changes properly.
Can you believe in the very following week I got an ad from HP for
their new HP-55 programmable calculator? If I had had that thing, I
could have solved the programming problem in just a couple of days.
The price was $499.99 for the complete set up, so I ordered it.
I never had reason to use it again. I did program a bunch of trivial
stuff, but nothing special. I sold it 10 years ago to a collector.
On Wed, 20 Oct 2010 16:45:13 -0700 (PDT), " firstname.lastname@example.org"
About that time, one of the engineers in regional office somehow
managed to get a purchase order issued for one of those. When
management discovered what had been purchased, it was decreed that it
should be locked in the safe when not in use. In 1977, I got a chance
to use it for a couple days and could see that it would be useful my
work but it would never be possible for me to take it home and play
around with it. I bought a Commodore PR100 with 100 program steps,
then, when the TI-59 came out, I got me one. Over the next five years,
I used that calculator regularly, then, I got stuck in regional office
away from the field and rarely used it and when I did need it, the
card reader had packed it in. now I have two of them downstairs
complete with printers, and wouldn't have a clue what to do with
I was a "starving student" in the early '70's, and when I bought my
texts for the '72 fall semester and had a look in the heat transfer
text, I knew that my slip stick would no longer suffice what with all
those fractional indicies calculations.
Went and bought a Digimatic D8 scientific calculator at Sears for
$Cdn182. 2 years later when doing extensive statistical calcs
(standard deviation calcs are a killer on non-stats machines) the key
pad crapped out and Sears replaced it for free. The boss loaned me an
HP45 calc and it was the cat's meow for the work at hand; but no way
could I justify the $500 or so it cost! One term tuition was around
$600 at that time.
I still have the D8 calc and it works fine.
Where I worked -- about the same time or a bit earlier, the head
honcho of the lab branch where I was got an HP 45 and kept it locked up,
letting nobody use it. He claimed that there was no need for any of his
people to need one.
About that time they were just below $400.00 -- and I decided to
buy one of my own -- with my *own* money.
I kept it on my belt, and took great pleasure in hauling it out
in meetings where he was present and answering questions requiring
calculation -- quite quickly -- to show how useful it was.
While I keep an HP-15C and an HP-16C (the computer math one) in
a belt pouch to this day. Some of these days, they will die and I will
not be able to get a replacement. (Apparently, HP has been convinced to
continue the HP-10C (business math), but not the scientific or computer
How long do you think they'll last?. I bought my first HP-11C in 1982
and it's still going. I though it was an expensive purchase at the time
when all around me were buying cheap Casios, usually the ones with the
extra functions on the flip open cover, but then the cover functions
would start to fail within a year IIRC due to flexing I suspect. I
started using HPs with my dad's old HP45 when he upgraded to a HP41C so
I'll probably be using RPN by choice till I have no other option.
We actualy have two HP-15Cs Shortly after I graduated I met the girl
who was to become my wife. She was in engineering school and needed
I will bet the diffrence between the HP-10C (buissnes model) and the
15 C guts is a jumper setting.
I have both, also. The 15C was going to get scrapped at work, the 16C
I forked out Big Bucks for back in '82 when it first came out. I was
working with a 36-bit mainframe, so the TI "programmers" calculator
didn't cut it. Needed up to 72 bits for double register ops and
converting EBCDIC to EBCD characters. Not a whole lot of messing with
paper dumps and machine language going on now, so there's probably not
a lot of call for a 16C on the market. Except for programability,
I've also got a $6 Sharp that does just about everything that the 15C
does except it doesn't use RPN. The rechargeable batteries seem to be
the weak spot on those old calculators, those HP "business-card" sized
ones use button cells so will probably keep chugging along as long as
the battery compartment doesn't get leakers.
And we bought a 4 banger with reciprocal and memory for (plug in wall)
for ... $600. It was pre any TI or HP calcs. I did logs on it and
trig. I was a Senior Adjunct Professor teaching 3 classes as a second
job. Calc crunching the numbers saved days of hand work.
We had some great apps - paper - methods - in EDN or Electronics back
then. By the middle 70's I was fully computerized doing histograms. :-)
On 10/20/2010 5:36 PM, Karl Townsend wrote:
I was a senior in high school in 1975... I'd had my good K&E bamboo
slide rule for about a couple of months when the first great price crash
for calculators hit. Suddenly a Melcor SC-535 (see
was available for under $100. That calculator got me most of the way
Now, of course, the two calculators I use are a mode in emacs and an
application on my phone.
As we enjoy great advantages from the inventions of others, we should
be glad of an opportunity to serve others by any invention of ours;
1982 my parents bought a HP 15C caculator for me as a bithday
present. Prof said my old calc wasn't up for my EE classes. It would
do matrices, complex number atrithmatic and had a iterive equation
solver. Saved me a bunch of time. Three sets of batteris later I
used it today. Havent used anything more complex than Y^X in 20
Now I use Mathmatic for almost everything besides numerical simulation
where MATLAB rules.
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