Any standard failure modes in old TI calculators?

[[email protected]]

We are on $5/mo pay-as you-go plans.

If you're that cheap, you can do even better.

Plenty for us. Virgin does have
smart phones but then AFAIK it pops up to $40/mo or so and I can't see
us using that. I hate it when people fidget around with their handheld
gizmos all the time. Some are literally obsessed. Middle of a nice
dinner ... *BING* ... "Oh, that could be so-and-so sending a text" ...
and out comes the schmart fone. Yuk.

Some people shoot people but that doesn't mean guns aren't useful.
Some people bury the people they've shot, but that doesn't mean
shovels aren't useful.

It's been good to me. I could not possibly have calculated all those
filters with a slide rule. Plus back then HP's were truly unaffordable
for the masses, you had to be on a professor's pay grade for those.

I was a poor married student in '73 when I took the HP plunge. It was
about ten weeks pay for me (three weeks, combined, for the two of us).
I wouldn't have bought an SR-50 at any price[*]. I think professors
were paid a bit more than that, even then. But then again, I'm not so
cheap that I can't afford more than a $5/mo. mobile phone now, either.
;-)

[*] Five people bought SR-50s the summer of my senior year and three
bought HP-35s (amplifier design course).The HP owners all got As and
the TI owners *all* flunked out. How's that for demonstrating the
difference! ;-)

BTW, I used a slipstick and got an A in the class - but it was smokin'
by the end of the final. The HP guys walked out early. I resolved to
join the HP generation right after that final. I got the HP45 in
November, IIRC.

 

[[email protected]]

The first calculator I ever encountered belonged to a school friend. It
came back from the US as his dad was a drugs rep. HP20 I think.

I RPN Obscure Very Find - Yoda.

Sure, RPN is easy. Just enter all the nouns then figure out what you
want them to do (verbs).

I was just lazy and liked entering formulae in normal order without
having to think. I got away with mental arithmetic and writing SR for
"slide rule" in the margin until first year uni. Answers to 3 sig fig
and SR did not go down at all well with our crystallography supervisor
so I got a calculator. SR51 - I have fond memories of it too.

The EE and ME profs took to calculators immediately. The prevailing
reasoning was that college was expensive already. A couple of hundred
bucks didn't make a significant difference. Calculators did (the
problems could be made much more realistic). Some the lesser
departments tried to ban calculators but the dean of engineering
overruled them (though academics, like Obama, don't bother with rules
they don't like).

 

[Joerg]

If you're that cheap, you can do even better.

It's not about being cheap, I just don't need any more than that.

[...]

It's been good to me. I could not possibly have calculated all those
filters with a slide rule. Plus back then HP's were truly unaffordable
for the masses, you had to be on a professor's pay grade for those.

I was a poor married student in '73 when I took the HP plunge. It was
about ten weeks pay for me (three weeks, combined, for the two of us).
I wouldn't have bought an SR-50 at any price[*]. I think professors
were paid a bit more than that, even then. But then again, I'm not so
cheap that I can't afford more than a $5/mo. mobile phone now, either.
;-)

[*] Five people bought SR-50s the summer of my senior year and three
bought HP-35s (amplifier design course).The HP owners all got As and
the TI owners *all* flunked out. How's that for demonstrating the
difference! ;-)

Well, now you know a SR-50 owner who did not flunk out

BTW, I used a slipstick and got an A in the class - but it was smokin'
by the end of the final. The HP guys walked out early. I resolved to
join the HP generation right after that final. I got the HP45 in
November, IIRC.

HP's were totally unaffordable over in Europe back then unless you had
rich parents. I thought about a Sinclair ZX81 but then decided to invest
that money into something real. Part for a monster RF amplifier.

 

[[email protected]]

It's not about being cheap, I just don't need any more than that.

I didn't until I had one, either. Same deal with a calculator,
computer,...

Slowly I get the feel this old SR-50 is toast. Even the pins of the SCOM
chip appear to have started some sort of dry-rot, all the way up to and
possibly into the chip.

Working as designed. ;-) I hated SR-50s. I would have stuck with my
slipstick if they were the only alternative.

It's been good to me. I could not possibly have calculated all those
filters with a slide rule. Plus back then HP's were truly unaffordable
for the masses, you had to be on a professor's pay grade for those.

I was a poor married student in '73 when I took the HP plunge. It was
about ten weeks pay for me (three weeks, combined, for the two of us).
I wouldn't have bought an SR-50 at any price[*]. I think professors
were paid a bit more than that, even then. But then again, I'm not so
cheap that I can't afford more than a $5/mo. mobile phone now, either.
;-)

[*] Five people bought SR-50s the summer of my senior year and three
bought HP-35s (amplifier design course).The HP owners all got As and
the TI owners *all* flunked out. How's that for demonstrating the
difference! ;-)

Well, now you know a SR-50 owner who did not flunk out

17% success rate still isn't great, particularly against 100% for HP.
;-)

HP's were totally unaffordable over in Europe back then unless you had
rich parents. I thought about a Sinclair ZX81 but then decided to invest
that money into something real. Part for a monster RF amplifier.

$400 (1973 dollars), when my income was ten times that wasn't exactly
"affordable" but I did it anyway. It was an investment.

 

[Spehro Pefhany]

Those sold for $20 in the US.

I remember $99. (very cheap at the time).


Best regards,
Spehro Pefhany

 

[Davej]

Gents,

My trusty old 1974-vintage Texas Instruments SR-50 is beginning to
sputter <sniffle>. It turns on and at first only reacts to very few keys

My 1983 vintage HP 41CV died some years ago. Maybe I should search the
web for repair ideas.

 

[Joerg]

It's not about being cheap, I just don't need any more than that.

I didn't until I had one, either. Same deal with a calculator,
computer,...

Slowly I get the feel this old SR-50 is toast. Even the pins of the SCOM
chip appear to have started some sort of dry-rot, all the way up to and
possibly into the chip.

Working as designed. ;-) I hated SR-50s. I would have stuck with my
slipstick if they were the only alternative.

It's been good to me. I could not possibly have calculated all those
filters with a slide rule. Plus back then HP's were truly unaffordable
for the masses, you had to be on a professor's pay grade for those.
I was a poor married student in '73 when I took the HP plunge. It was
about ten weeks pay for me (three weeks, combined, for the two of us).
I wouldn't have bought an SR-50 at any price[*]. I think professors
were paid a bit more than that, even then. But then again, I'm not so
cheap that I can't afford more than a $5/mo. mobile phone now, either.
;-)

[*] Five people bought SR-50s the summer of my senior year and three
bought HP-35s (amplifier design course).The HP owners all got As and
the TI owners *all* flunked out. How's that for demonstrating the
difference! ;-)

Well, now you know a SR-50 owner who did not flunk out

17% success rate still isn't great, particularly against 100% for HP.
;-)

Well, I only knew one guy who spent his complete (!) savings and then
some on a programmable HP with printer, memory extension and whatnot.
AFAIK he never achieved his master's degree. From the TI guys that I
knew maybe half. Which was high for my alma mater, back then they had a
83% flunk-out rate. So 50% for TI guys, 0% for HP guys. I don't know
about the guys with Commodores and others.

$400 (1973 dollars), when my income was ten times that wasn't exactly
"affordable" but I did it anyway. It was an investment.

I was a highschool student at that time but with a dire need to speed up
my filter calculations and stuff. For me $400 was definitely
unaffordable. The highest paying vacation job was a grueling one in a
meat factory and that paid $3-$4/h. All muscles ached, some you didn't
even know you had.

 

[Joerg]

Those sold for $20 in the US.

Only in an inventory sell-off. I had the prices from the US back then,
in magazines. They were well over $100. Which was still a ton less than
in the Netherlands though.

 

[[email protected]]

[email protected] wrote:
[email protected] wrote:
[email protected] wrote:
Uwe Hercksen wrote:
Joerg schrieb:

No RPN though which throws me a curve every time.
Hello,

if you are really used to RPN, you have problems using another
calculator without RPN.

True, and I do. But it does train the brain so I like the challenge,
just like driving a car with right-hand steering. I also am sometimes
forced to use non-RPN because I often don't take my HP on the road. The
usual, some innocent EMC job and then they need me to also fix internal
noise and calculate a filter, on whatever calculators they have. Lately
on guy handed me his smart phone turned calculator. No RPN either and
then you have no time to load a new app.
I carry my HP11C (emulator) everywhere I go. Well, I don't carry my
cell phone around the house. ;-) Loading a new app on my cell phone
takes all of 30 seconds.

Can't do that. My cell is a no frills phone-phone. No apps possible,
whatsoever. Kids think it's a steampunk model.
We had those until we took the plunge and bought Android phones in
January. We make very good use of them and haven't been sorry at all.

We are on $5/mo pay-as you-go plans.
If you're that cheap, you can do even better.

It's not about being cheap, I just don't need any more than that.

I didn't until I had one, either. Same deal with a calculator,
computer,...

Slowly I get the feel this old SR-50 is toast. Even the pins of the SCOM
chip appear to have started some sort of dry-rot, all the way up to and
possibly into the chip.

Working as designed. ;-) I hated SR-50s. I would have stuck with my
slipstick if they were the only alternative.

It's been good to me. I could not possibly have calculated all those
filters with a slide rule. Plus back then HP's were truly unaffordable
for the masses, you had to be on a professor's pay grade for those.
I was a poor married student in '73 when I took the HP plunge. It was
about ten weeks pay for me (three weeks, combined, for the two of us).
I wouldn't have bought an SR-50 at any price[*]. I think professors
were paid a bit more than that, even then. But then again, I'm not so
cheap that I can't afford more than a $5/mo. mobile phone now, either.
;-)

[*] Five people bought SR-50s the summer of my senior year and three
bought HP-35s (amplifier design course).The HP owners all got As and
the TI owners *all* flunked out. How's that for demonstrating the
difference! ;-)

Well, now you know a SR-50 owner who did not flunk out

17% success rate still isn't great, particularly against 100% for HP.
;-)

Well, I only knew one guy who spent his complete (!) savings and then
some on a programmable HP with printer, memory extension and whatnot.
AFAIK he never achieved his master's degree. From the TI guys that I
knew maybe half. Which was high for my alma mater, back then they had a
83% flunk-out rate. So 50% for TI guys, 0% for HP guys. I don't know
about the guys with Commodores and others.

$400 (1973 dollars), when my income was ten times that wasn't exactly
"affordable" but I did it anyway. It was an investment.

I was a highschool student at that time but with a dire need to speed up
my filter calculations and stuff. For me $400 was definitely
unaffordable. The highest paying vacation job was a grueling one in a
meat factory and that paid $3-$4/h. All muscles ached, some you didn't
even know you had.

I was paid $2/hr as a technician ($2.25 by the time I graduated) for a
20hr max week. My wife made the same as a nurse's aid in a nursing
home.

 

[Joerg]

[...]

I was a highschool student at that time but with a dire need to speed up
my filter calculations and stuff. For me $400 was definitely
unaffordable. The highest paying vacation job was a grueling one in a
meat factory and that paid $3-$4/h. All muscles ached, some you didn't
even know you had.

I was paid $2/hr as a technician ($2.25 by the time I graduated) for a
20hr max week. My wife made the same as a nurse's aid in a nursing
home.

Couldn't get tech jobs where I was living. The meat factory job was
really tough. Lifting batches of 36 to 42 big long and wet Italian
salami sausages into smoker's racks all day long was my main job there.
In essence the perfect weight lifter training. I did not want to become
a weight lifter but it was the highest-paying job in the area. Mainly
because nobody wanted to do it or they didn't last through the first
day. The bicycle ride was 7-8 mile each way and in the evening that was
painful. Made enough money during school break to buy myself a used
shortwave transceiver and some other ham radio gear, things a school kid
could normally never afford.

 

[[email protected]]

[email protected] wrote:
[email protected] wrote:

[...]

BTW, I used a slipstick and got an A in the class - but it was smokin'
by the end of the final. The HP guys walked out early. I resolved to
join the HP generation right after that final. I got the HP45 in
November, IIRC.
HP's were totally unaffordable over in Europe back then unless you had
rich parents. I thought about a Sinclair ZX81 but then decided to invest
that money into something real. Part for a monster RF amplifier.
$400 (1973 dollars), when my income was ten times that wasn't exactly
"affordable" but I did it anyway. It was an investment.

I was a highschool student at that time but with a dire need to speed up
my filter calculations and stuff. For me $400 was definitely
unaffordable. The highest paying vacation job was a grueling one in a
meat factory and that paid $3-$4/h. All muscles ached, some you didn't
even know you had.

I was paid $2/hr as a technician ($2.25 by the time I graduated) for a
20hr max week. My wife made the same as a nurse's aid in a nursing
home.

Couldn't get tech jobs where I was living.

Well, I was in college and the university had a few. I got the job
for two reasons. I was a local (my father was a prof), so I was
around in the summer and on breaks, when all the maintenance was done.
And the second reason, well, is there in the first. ;-)

The meat factory job was
really tough. Lifting batches of 36 to 42 big long and wet Italian
salami sausages into smoker's racks all day long was my main job there.
In essence the perfect weight lifter training. I did not want to become
a weight lifter but it was the highest-paying job in the area. Mainly
because nobody wanted to do it or they didn't last through the first
day.

Supply and demand is a good thing.

The bicycle ride was 7-8 mile each way and in the evening that was
painful.

I rode my bike to school and work, though it wasn't all that far (3-4
miles). My wife took the car, since I couldn't park on campus. In
bad weather she'd drop me off at 6:00AM and I'd catch a few Zs,
sitting in the chair at work before everyone else showed up.

Made enough money during school break to buy myself a used
shortwave transceiver and some other ham radio gear, things a school kid
could normally never afford.

I had a nice receiver (Heathkit SB-301) when I was in high school. I
sold it when I was in college because I didn't have the time (or
space) for such things. I needed the money, too. Never wanted to go
back to it, though.

 

[josephkk]

Also, mine has a chronic case of lousy bettery contacts. I've
temporarily fixed a few of these by just spinning the 4 N type
batteries. I've also seen calculators where only one out of the 4
batteries is drained, while the others are at full charge. I have no
clue what causes that effect since they're all in series.

Those are NiCd cells, they can develop internal shorts due to whisker
growth. Take the dead cell and pop it in parallel with a 22,000 uF cap
charged to 12 V or so. The whisker ceases to be and the terminal voltage
comes back. Do take care to use normal polarity.

?-)