OT Can people not do mental arithmetic or use a calculator any more?
Jun 22, 2022 Last reply: 4 years ago 266 Replies
J
Joe
I'm not sure it was by choice. Sinclair used a four-function calculator chip and reprogrammed it to do scientific functions, though very slowly. I suspect he was then pushed for space.
This was quite small, and used AAA batteries, which didn't help. The LED display was so small than each digit had a plastic magnifying bubble over it. But there was no other scientific calculator anywhere near it in price, which I think was GBP14.99, a fiver more if bought assembled.
Didn't find your answer? Ask the community — no account required.
J
Joe
I believe they all do, as counter-intuitively, the two stages are much easier than compiling the expression directly.
A
Andy Burns
My first two calculators one was a VFD display, the other a red LED, they did indeed eat batteries ...
formatting link
formatting link
N
NY
Ah the good old VFD display. The first normal (not RPN) calculator I used was a Sinclair (I think) that just did the four functions and nothing else: cheap and cheerful. But batteries only lasted a few days. At least my dad's HP45 used a rechargeable battery so the only cost was the mains to recharge it.
I'm surprised that anything still uses VFDs, but about 10 years ago I was staying in a holiday apartment and the new cooker had a VFD for the clock. And that had a horrible flicker: I think they must have been pulsing each segment in turn at mains frequency, rather than at several kHz, so if you saw the display out of the corner of your eye (flicker is most noticeable in peripheral vision) it looked horrible.
I wonder if any calculators ever used those neon Nixie tubes? ;-)
I remember wondering why "new" (in the 1970s) digital watches with LED displays only displayed the time for a few seconds and then blanked the display, instead of displaying the time permanently as with an analogue watch that had hands. Then I worked out the current consumption and realised why the display wasn't on permanently.
M
Max Demian
I had (use of) a calculator with VFD display in the 70s. The display was blue behind a green tinted screen. It was powered by 2 AA batteries. You could use alkalines or NiCads. There was a mains unit which could power it directly or charge the NiCads if present. I suppose there must have been some kind of voltage multiplier as I thing VFDs need about 18V for the HT.
A
Andrew
Indeed. Some details of how they did it are here:
formatting link
Pretty impressive really.
S
SteveW
Desktop calculators certainly did - things almost the size of a PC base unit, that only did the four basic maths functions + square root.
Like this:
formatting link
I took one apart many years ago (I wish I'd kept it) and that one had a small (probably 1-1/2 square IIRC) insulated board, with magnetic rings on a copper wire matrix as its memory.
D
Dave Plowman (News
It was my point, really. I could manage on a zero spend for groceries if I eat out all the time.
D
Dave Plowman (News
I'll ask again. Are you retired etc, so take each and every meal at home?
A
ARW
I do not remember living in a house without gas central heating - but I did until I was 4 years old.
In the 80's when I worra lad we also had a coal fire as my Dad used to get a coal (smokeless fuel) allowance and if you did not take it you lost it.
That was a complete waste of a set up as it only heated the lounge and did not heat the DHW. Although to be fair in winter if you built the fire up a bit at night and left the lounge to hall door open it kept the house warm.
B
Bob Eager
Not necessarily. Recursive descent will do it on one, and I've used that in the past.
B
Bob Eager
I've just been doing that, too. To mimic the IBM HFP instructions (hex floating point). Well, almost.
S
soup
And yet you 'say' it is stupid not having one!
T
Tim+
Not as stupid as arguing with a known troll.
Tim
D
Dave Plowman (News
My parents house had a back boiler to the coal fire as built in the 30s. Which did the hot water. The cylinder was changed to one with an immersion heater for when the coal fire wasn't needed.
I can remember coal being delivered by a steam lorry.
A
ARW
When I was skint I used to make then for work - or make pasta meals etc
When actually working away and stopping overnight we are given £20 cash upfront for every night you are away.
I could not spend that when working in London on Oxford Street (well I could - but it was easy not to). There was a Sainsburys 2 minutes away from work and loads of takeaways and a Wetherspoons around the corner from the digs.
Actually I did spend it, but that was at the bar and not on food :-)
R
Robin
Just in case you don't already know, HMRC now allow up to £25 tax- and NICs-free. And you could argue London needs a higher rate than other UK places. But probably best not cite the £8 pints of beer as evidence
formatting link
A
ARW
It £5 a pint or more up here.
S
SteveW
Just paid £4.50 a pint when helping my son move his stuff from university halls to a shared house in Headingley today.
A
Andy Burns
I think it was around that price +/- 20p around Peterborough on Jubilee piss-up Thursday.
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required
Report Content
You are reporting this content to the moderators. They will look at it
ASAP.