Early 70s Calculators

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martinw
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Early 70s Calculators

Postby martinw » Sat Nov 26, 2016 10:06 am

Here are a few of my latest acquisitions :) (actually early Christmas presents and most of them arrived yesterday :oops:)

I really bought them (to a certain extent) for the old ICs inside them as I think they're quite beautiful things in their early white ceramic packages etc.

I also (through this) learnt about the early microprocessors and the whole Pico/General Instruments (GI) development process; very interesting as I use a lot of PIC microcontrollers in my work life and it all started just down the road from me here in Fife of all places =D>

http://www.spingal.plus.com/micro/

Anyway, enjoy the images if you're into the devices that really spawned the modern day micro computer (to a certain extent).

Early 70s Calculators Above.jpg


Early 70s Calculators Display.jpg


Texas Instruments Early Processor.jpg


General Instruments 250 Processor.jpg


Texas Instruments Early ICs.jpg


All in all I now own a GI 250 processor (designed in Scotland) and aren't the ICs in the Monroe 10 the most beautiful ICs you've ever seen :D

I also think it's quite interersting how the method of displaying the calculations evolved, thermal paper in the Monroe 10, 4 single VFD tubes in the Litton where you had to scroll the calculation from left to right to see it and eventually LEDs 8)

Martin

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sweh
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Re: Early 70s Calculators

Postby sweh » Sat Nov 26, 2016 9:18 pm

Heh. The first calculator my parents owned was a PYE 630 (http://www.vintagecalculators.com/html/pye.html#P630). They kept it for decades but I think they junked it after noticing the soldered-in rechargable batteries had made a mess. It really wasn't a good calculator (didn't even know order of operator precedence) but I did teach it a game (kinda...)

Without looking at the screen type in a 5 digit number then press "/" "k" "=". It should say "1". Press "=" again and you get a decimal. At least I think that's how I set it up. This was when I was 8 or so.

Now you need to guess the number; type in your guess, press "=". If the answer is >1 then it's too high; <1 and it's too low.

(You can do the same on many modern calculators by doing "numbers" "/" "/" "=" - the double operator works the same as the Konstant).
Rgds
Stephen

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martinw
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Re: Early 70s Calculators

Postby martinw » Mon Dec 19, 2016 6:55 pm

LS ICs from 1970 ...

IMG_3431.JPG


... I was hoping for ICs from 1970 when I bought the calculator (can you guess what calculator they're from?) as these are now the earliest (non MS) ICs I now own =D>

Martin

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Re: Early 70s Calculators

Postby hoglet » Mon Dec 19, 2016 7:00 pm

martinw wrote:can you guess what calculator they're from?

A Sharp EL-8?
https://en.wikipedia.org/wiki/Sharp_EL-8

Dave

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Re: Early 70s Calculators

Postby martinw » Mon Dec 19, 2016 7:15 pm

You're right Dave, it's very well put together.

IMG_3432.JPG


IMG_3434.JPG


A veritable Volvo of early 1970s calculators 8)

Martin

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Re: Early 70s Calculators

Postby BigEd » Mon Dec 19, 2016 7:16 pm

Good spot Dave! Photos here:
http://www.johnwolff.id.au/calculators/ ... EL8-8M.htm
The EL-8 processor board (left) has a component area of 76 x 87mm and carries four Rockwell MOS-LSI chips in 42-pin ceramic flat packs. The part numbers are AU2271, NRD2256, DC2266, and AC2261, with date codes for weeks 42 and 43 (ie, October) of 1970. The board itself is date-stamped 45-12-9 on the back (ie, 9 December 1970).

The metal-can package is a CG1121 clock generator, producing a two-phase clock at about 45KHz (and a number of timing signals) from a 90KHz master oscillator.

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Re: Early 70s Calculators

Postby martinw » Mon Dec 19, 2016 8:08 pm

That's it now, presents for Christmas 2016 ... done!

IMG_3438.JPG


IMG_3439.JPG


IMG_3440.JPG


IMG_3441.JPG


My wife will probably divorce me if I keep going at this rate, so that's it for now :oops: :wink:

Have a very merry Christmas everybody :!:

Martin

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Re: Early 70s Calculators

Postby martinw » Tue Feb 14, 2017 10:01 am

Had to buy it, just to see if it had LSI ICs earlier than my Sharp EL8 in it; unfortunately not, but it is working ... with rechargeable batteries (not the originals of course :lol:)

Sanyo ICC82D Rechargeable Batteries.jpg


Mid 1970 is still my earliest LSI IC ... still on the hunt for one from 1969 if it ever existed [-o<

Early 70s Calculator ICs.jpg


Martin

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Re: Early 70s Calculators

Postby BigEd » Tue Feb 14, 2017 10:31 am

Sanyo ICC-82D: "Display is 8 digits amber gas-discharge tubes" - sounds pretty battery sapping to me!
http://www.vintagecalculators.com/html/ ... c-82d.html
Bigger than I expected:
Image

Interesting idea to hunt for a 1960s IC. Sounds like you'll need a desktop calculator for that.

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Re: Early 70s Calculators

Postby martinw » Tue Feb 14, 2017 11:17 am

Aye, it's a chunky thing :shock:

It's pretty amazing the difference in size between the really early 1970s calculators and the ones a couple of years later.

Probably the same goes for the late 1960s to the early 1970s ones too.

I think you're right regarding the desktop calculators and the earlier ICs :D

Martin

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Re: Early 70s Calculators

Postby ThomasHarte » Tue Feb 14, 2017 4:50 pm

I've got a Sinclair Oxford 300 from 1975, so probably not quite the early '70s, and can confirm it to be very boring inside other than in that classic Sinclair sense of "wait a minute, where's the rest of it?". This Google Images represents more or less what I remember from when I looked:

Image

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Re: Early 70s Calculators

Postby BigEd » Tue Feb 14, 2017 5:52 pm

That was my first calculator!

Fans of Sinclair's products, of extreme engineering, or of reverse engineering, might be interested to visit
righto.com/ti
righto.com/sinclair
and note that Nigel Searle took the chip from the four-banger TI Datamath and built the RPN Sinclair Scientific using just 320 words of on-chip ROM. Commented code within, and explanation of the algorithms. Compared to anything but a slide rule, it was slow and inaccurate. This was 1974 or so.

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Re: Early 70s Calculators

Postby martinw » Wed Feb 15, 2017 8:57 am

I originally bought the Sinclair Executive Memory to see what ICs were inside it, but after a bit of tugging on the case I realised it was glued shut!

The Sinclair Executive was streets ahead of the competition from a size perspective, at the time that it was brought out (from what I can tell).

Chris Curry seemed quite proud of it in a video interview on YouTube, where he mentioned it.

Martin

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Re: Early 70s Calculators

Postby martinw » Wed Feb 22, 2017 7:12 pm

1970 (ish) on the left ... to ... 1973 (ish) on the right.

IMG_3639.JPG


Martin

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Re: Early 70s Calculators

Postby flaxcottage » Wed Feb 22, 2017 8:58 pm

My earliest calculator from the 70s was the white Sinclair Scientific. It was a kit bought in 1974 and worked first go!

At the time it was an amazing machine considering the price. Unfortunately it was not the most accurate and the build quality was not the best and it died after a few years.

It was replaced by a Texas SR56 in 1977. This is a programmable scientific calculator. It is quite quick and very accurate.
IMAG0602.jpg


It has seen a lot of hard use and is still fully functional today. The NiCad cells needed replacing a few years back and will probably soon need to be replaced again.

When I got my UK101 in 1979 the SR56 was relegated to being a simple calculator and got little use afterwards.

About 5 years ago I was lucky to acquire a HP-41CX, barcode reader, printer and card reader and this has taken over my calculator needs (not a 70s machine I know :( ) The HP is a beast!
- John

Currently running Level 4 Econet with BBC B, BBC B+ 128K, Master 128K, 4Mb A3000, 4Mb A3020, 4Mb A4000, 4Mb A5000 dual FDD; UK101; HP41CX setup; Psion 3a, 3mx and 5mx; Z88; TI-58c, TI-59 and printer, HP-16C programmer's calculator

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Re: Early 70s Calculators

Postby Seldon2k » Fri Jul 07, 2017 8:12 pm

I have owned the following calculators though the 1970's, in approximate chronological order.

Memory Master (Four function)
Image

Memory Master M (Squares, square roots and inverse)
Image

Sinclair Scientific (Built from a kit, my first scientific, it used Reverse Polish Notation.)
John: Mine still works :-) except that the battery contacts are corroded.
Image

Here is an online Emulator to allow you to experience this calculator in all of its inaccurate glory.
John: My Maths teacher took great delight when this calculator gave its answer for Tan(45) as 0.99990, (Tan{PI/4} actually)
http://files.righto.com/calculator/sinc ... lator.html

Texas Instruments TI-51 mk III Programmable (32 Steps, 10 Memories)
Image

Texas Instruments TI-58 Programmable (480 Steps, 60 Memories)
Image

When I got my UK101 in 1979 the TI-58 was relegated to being a simple calculator and got little use afterwards.
John: I find myself amazed at the parallel life path & common interests we have :-)

Texas Instruments TI-59 Programmable (960 Steps, 100 Memories)
Image

Texas Instruments PC-100 Print Cradle for the TI-58 & TI-59's
Image

Texas Instruments SR-56 Programmable (100 Steps, 10 Memories)
I acquired this in the early 21st Century, because it was the smaller brother of the SR-52 (224 Steps, 20 Memories)
, http://www.datamath.org/Sci/WEDGE/sr-52.htm, that I had first seen and envied at a friends house in 1976.
Image

I also aspired to but never acquired the HP-41CV
Image
John: I was attracted by the barcode reader, printer and card reader you are now lucky enough to own :mrgreen:

I have added a few more to my collection over the last 10 years, I may add these later.
They are all early 1970's four function calculators.

Terry (Seldon2k)

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Re: Early 70s Calculators

Postby flaxcottage » Mon Jul 10, 2017 9:26 pm

Seldon2k wrote:John: I find myself amazed at the parallel life path & common interests we have :-)


Crikey, Terry! Don't say there are two of us. My wife will lose what little sanity she has left. :lol: :lol:

It gets even worse. I received a SR-51A this weekend.
SR-51A.jpg

This has an elegant design, I feel. Unfortunately it was a non-working machine. Maybe I can fix it??? I bought it for the battery pack which I needed so that I have a working pack for both my 58 and 59 after rebuilding it.
- John

Currently running Level 4 Econet with BBC B, BBC B+ 128K, Master 128K, 4Mb A3000, 4Mb A3020, 4Mb A4000, 4Mb A5000 dual FDD; UK101; HP41CX setup; Psion 3a, 3mx and 5mx; Z88; TI-58c, TI-59 and printer, HP-16C programmer's calculator

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Re: Early 70s Calculators

Postby Lardo Boffin » Tue Jul 11, 2017 8:25 am

I recently saved three calculators from the bin and seeing this post I thought I would put them up here. I suspect this should be in the giveaway section but thought it might not get noticed.

I think they are late 70's through the mid 80's but if anyone wants them they are welcome to them for the price of p&p - probably Royal Mail small parcel.

The Sharp sadly had its batteries still inside when I got them and there was leakage. No idea if these work as I don't have the correct size batteries to test so given away 'as seen :D !'

IMG_6373.JPG


PM me if interested. Happy to add more photos if required. Otherwise it is back in the tin with the Soundblaster 16 from 1995...

IMG_6374.JPG


Lardo
BBC model B 32k issue 4, 16k sideways RAM, Watford 12 ROM board, Retroclinic Datacentre + HDD, matchbox co-proc, Viglen twin 40/80 5.25" discs, acorn cassette
BBC model B 32k issue 7, turboMMC, Opus Challenger 3 512k, Pi 3 coproc, Acorn 6502 coproc

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Re: Early 70s Calculators

Postby flaxcottage » Tue Jul 11, 2017 9:35 am

What a great find. 8)

I love the M-120. A musical calculator. I remember the days when shops like WH Smiths had a whole department devoted to calculators.

I never really got into Sharp and Casio calculators. I found them difficult to use on an everyday basis. They soon had calculators which purported to be for O-Level (now the much revised and superior GCSE :^o ) and which needed a degree in mathematical logic to use. :?

For me the Texas range with orange, brown and beige buttons (very 70s) were perfect, especially the programmable ones. It is laughable now to think that these calculators satisfied my data processing needs until 1979 when I got my first computer.
- John

Currently running Level 4 Econet with BBC B, BBC B+ 128K, Master 128K, 4Mb A3000, 4Mb A3020, 4Mb A4000, 4Mb A5000 dual FDD; UK101; HP41CX setup; Psion 3a, 3mx and 5mx; Z88; TI-58c, TI-59 and printer, HP-16C programmer's calculator

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Re: Early 70s Calculators

Postby Seldon2k » Tue Jul 11, 2017 4:59 pm

John:
I have found that the trick with old TI calculators is to remove and refurbish the battery pack.
Then jump in a Laboratory PSU set to the appropriate voltage of the pack, by this I mean if a three
cell pack then use jumpers to inject 3.6v to 4v at the battery contacts in the calculator.
I then work the on/off switch a few times and they spring back to life. :D

This last may indicate a capacitor issue, I have just looked at the circuit diagram of the TI-59 and
I suspect C1, C3 or C4.

TI-58_9 PSU.png

As I have only had this 'won't wake up' issue with TI-51-III / TI-57 this is just speculation.

Note to self:
Look into using 3.7v Lithium Ion phone batteries in TI calculators to run them from USB PSU's and
Computers. Consider using these or similar
http://www.batteryspace.com/USB-3.7V-Li-ion/Polymer-Charging-Module.aspx
http://lygte-info.dk/review/Review%20Charger%20TP4056%20UK.html

Terry (Seldon2k)

PS. Love the phrasing about the GCSEs. =D>

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Re: Early 70s Calculators

Postby martinw » Sun Oct 08, 2017 1:32 pm

A Busicom Junior (version 1), wouldn’t want to try to lift the senior version, this is heavy enough :lol:

CEFC9BD1-F70F-4C0F-90C7-49A3133D2584.jpeg

CEA7CAEC-9E16-4E54-BA2E-BA318CD5D26A.jpeg

E7DF7AF7-ED3D-4F8A-B715-C3D8AD39C3FA.jpeg

BF5478AB-3A07-4178-91B6-103D9B39CC9F.jpeg


Anybody any idea on the IC date codes, should be 1970 or before ...

Here's the calculator doing 22 divided by 7, simple things ... :lol:

https://youtu.be/VO5z7kZ1ugo

Martin
Last edited by martinw on Thu Oct 12, 2017 12:34 pm, edited 1 time in total.

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Re: Early 70s Calculators

Postby flaxcottage » Sun Oct 08, 2017 1:42 pm

Quite a little museum you have going, Martin.! :mrgreen:

I love the green 'tubes' in the calculator display.
- John

Currently running Level 4 Econet with BBC B, BBC B+ 128K, Master 128K, 4Mb A3000, 4Mb A3020, 4Mb A4000, 4Mb A5000 dual FDD; UK101; HP41CX setup; Psion 3a, 3mx and 5mx; Z88; TI-58c, TI-59 and printer, HP-16C programmer's calculator

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Re: Early 70s Calculators

Postby martinw » Sun Oct 08, 2017 2:38 pm

Cheers John :D

Yes the display tubes on these early calculators are very cool 8)

Martin

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Re: Early 70s Calculators

Postby Wouter Scholten » Wed Oct 11, 2017 4:26 pm

Lardo Boffin wrote:I recently saved three calculators from the bin and seeing this post I thought I would put them up here. I suspect this should be in the giveaway section but thought it might not get noticed.

I think they are late 70's through the mid 80's but if anyone wants them they are welcome to them for the price of p&p - probably Royal Mail small parcel.

The Sharp sadly had its batteries still inside when I got them and there was leakage. No idea if these work as I don't have the correct size batteries to test so given away 'as seen :D !'

IMG_6373.JPG

PM me if interested. Happy to add more photos if required. Otherwise it is back in the tin with the Soundblaster 16 from 1995...

IMG_6374.JPG

Lardo


The Casio ML-120 is cool for being so unusual. Typing numbers gives sounds, recalling a number from memory gives the sounds of all digits (and dot)...

I'm not keen on the TI calculators, they are dog slow compared to Casios. Also the keyboard sucks... I made some comparisons of a TI-58C and various HPs and TIs many years ago. At school I remember the test to see about speed is 69! and TI was always slow. Even worse with the TI-58(C) as it's not a hardwired function. The TI-58 is about half the speed of the HP-41 caused by the extremely slow load/stores, as I discovered in my tests. And the HP-41 is already slow compared to the Casio FX-501P/602P etc. I may resurrect that page some time... The HP-41 is cool but the HP-41 was really expensive. Casio gave the best value, with the 50xp and 60xp having good keyboards, far better than the TIs and hardly less than the clicky HP keyboard. Also the programming model is really bad with TI (you don't get feedback on what you typed in as you always see the next memory location's contents...)

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Re: Early 70s Calculators

Postby flaxcottage » Wed Oct 11, 2017 5:27 pm

Ha! I smell a whiff of calculator wars coming on. :lol: :lol:
- John

Currently running Level 4 Econet with BBC B, BBC B+ 128K, Master 128K, 4Mb A3000, 4Mb A3020, 4Mb A4000, 4Mb A5000 dual FDD; UK101; HP41CX setup; Psion 3a, 3mx and 5mx; Z88; TI-58c, TI-59 and printer, HP-16C programmer's calculator

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Re: Early 70s Calculators

Postby Wouter Scholten » Thu Oct 12, 2017 9:01 am

flaxcottage wrote:Ha! I smell a whiff of calculator wars coming on. :lol: :lol:


Ha, it's unlikely now :) Actually I wonder whether the fanatics at that time objectively compared all devices, or were just in one camp because "that is what they bought". Such issues strongly affect a lot of people, who identifify the device with themselves and criticism on a device is regarded as criticism on themselves... If you wonder, I had a 602p, later a 41cx. I like both, TI not so much. I was interested in buying a TI-88 after reading a brochure, but it never came. From trying out the TI-58C, I would have disliked the keyboard, unless they improved it compared to such earlier TIs.

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Re: Early 70s Calculators

Postby BigEd » Thu Oct 12, 2017 10:35 am

My perception from BITD:
    Sinclair: remarkable
    Commodore: affordable
    TI: capable
    HP: unattainable
For some reason, Casio and Sharp didn't pique my interest much. Later on, I came to like Sharp.

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Re: Early 70s Calculators

Postby 1024MAK » Thu Oct 12, 2017 11:22 am

BigEd wrote:My perception from BITD:
    Sinclair: remarkable
    Commodore: affordable
    TI: capable
    HP: unattainable
For some reason, Casio and Sharp didn't pique my interest much. Later on, I came to like Sharp.

From my perspective, it was rather different...
At school when I discovered that electronic calculators existed, I had never heard of Sinclair, let alone Commodore.

So my first calculator was this one:
IMG_5393.JPG
Casio Personal M-1

My parents gave it to me, but IIRC they already had it, so it was not new when I got it. I used this one for years.

But later on, I needed a calculator that could do more than add up, subtract, multiple and divide. So I looked through what was in the shops, and asked my parents for this one:
IMG_5394.JPG
Casio fx-451
IMG_5395.JPG
Casio fx-451

Which could also work with binary and hexadecimal, just right for someone doing computer studies :wink:
This was my second calculator, and as it happens, the first new and the last new calculator that I have ever had. Well, that's not quite true, I did buy a cheap calculator watch when at school. A bit of cheap junk. And I got a small basic calculator free with something once.

TI looked too complicated and were not cheap and I don't remember HP, but that may be because they were too expensive or not on sale in our local shops. The shops being WH Smiths, Boots, Woolworths, Argos and Dixons.

But in the later years at school, or it may have been at technical college, I wanted a calculator that could run BASIC programs. Like the 'rich' kid had (I have no idea if he was rich...).

Browsing eBay, as you do, somehow I found myself looking at calculators (I blame this thread). So of course, when I saw a Casio PB-410 going for a reasonable price, well...
IMG_5396.JPG
Casio PB-410F

I have no idea what model I played with when I was younger, but it does not matter.

Excluding mains powered computers, my next step, was Psion Series 3...

And they all still work, as you can see in the photos :D

Mark
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Re: Early 70s Calculators

Postby BigEd » Thu Oct 12, 2017 11:30 am

Two excellent Casios there!

I have two notable memories of Casios:
- that one of the lesser models could do the functions of one of the more capable models, but lacked the keyboard legends for them. Combinations and permutations, and rectangular/polar conversions, IIRC.
- that by pressing more than one digit at the same time, you could get non-decimal digits (the degree sign, the E indicator) which would then behave in interesting ways.

Oh, and another memory comes to me now: opening the case of a Casio and finding that it wasn't really intended for opening and reclosing - I think a clip broke. Oops. Not my Casio...

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1024MAK
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Re: Early 70s Calculators

Postby 1024MAK » Thu Oct 12, 2017 11:37 am

I should add that the fx-451 keyboard is a bit mucky 'cus it still gets used on a regular basis, even when there is a computer, Psion, iPhone and iPad mini within reach :D

Although these days I never fold the "case" shut anymore, it just stays open and flat like in the photos.

Mark
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