What was your first micro programming experience?

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By the time I got to touch 4000 series cmos, they were up to the B series. They were pretty robust for me. They did have a nasty habit of coupling faults on the output back to the inputs. This made fault finding tricky.

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The first 50 ICs I pulled out of an old parts box were half A-series and half B. I was similarly lucky and never zapped a part.

- John

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Today, purely by chance, I discovered that the first two computers I had - a Sinclair MK14 and a Microtan 65 - are both now available as replicated boards. More to the point, I can get 74s571 4x512 memories filled with the original Sinclair code - which is handy as mine have severe bitrot.

 

Neil

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All you old timers make me chuckle.  My first micro programming experience was on an ATmega128, and I promptly joined AVRFreaks for help.  My first programming experience was on a CDC6600 in the early '70s, just when it gave up it's title as the fastest computer in the world, according to Wikipedia, to the CDC7600, which I did my thesis calculations on.  I went to the University of Minnesota, and CDC was a Minnesota company, so we always got the latest and greatest from CDC, probably beta versions.  If I had been smarter I would have learned assembler, but our group did everything in FORTRAN.  I still dont know assembler.  That's what compilers are for.  I seem to remember the maximum memory I could request was 107k octal, but I think those were 64 bit words.

 

What are the first mainframes all you old timers worked on?

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I am probably still a little young to be an old timer.

 

For about four months, from 2200 until 0300 each night, I was essentially the only user on a Cray 1. It had a magnificently fast FORTRAN compiler and mass storage, that chewed through a (virtual) 100 000 card deck in 0.7 seconds.

- John

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I have a friend who worked at Cray in the early days, and he liked to say he had the fastest FFT in the world.  I would tell him that wasn't such a huge honor seeing how he was doing it on the fastest computer in the world.  I never got to work on a Cray, but lots of Prime's and IBM's.

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Speaking (indirectly) of Seymour Cray, a while back I read a great book, "When Computers Went To Sea," about the digitization of the US Navy in the 50s and 60s.  Cray designed the original hardware, the AN/USQ-17.  Apparently (IIRC) it was intended to be a 32-bit computer but the germanium transistors available just didn't have the drive (for what?  carry?), so it ended up being a 30-bit design.

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 I have NEVER lost a single 4000 series chip handling/soldering thousands 

The lead poisoning probably erased your memory...surprise  Actually, how did we survive flux, lead, trichor cleaner, acetone & everthing else that is banned.

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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The CD4000 chips were great because they could drive LEDs directly. 

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So could TTL. The 4000 series cmos had really poor current drive coupled with old tech LEDs, meant very average brightness.

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Indeed, if you powered it at TTL supply voltages. Traditional CMOS does much better at 12–18V. Or you can use 4049/4050 buffers which, driving an LED, have minimum sink and source currents of 10 mA at 5V, or 20 mA typical.

 

I am currently designing a simple digital camera tether, with 4000-series CMOS, to see what I have learned and forgotten over the years. It will directly drive its LEDs without resistors. At 5V, the first half dozen, recent production ICs I have tried, all source and sink a bit better than the typical values in their datasheets. As does some good, socialist, new/old stock from the former East Germany. I suspect manufacturing tolerances have tightened a little over the last five decades.

 

So far the controller needs three more parts than an AVR-based design, with the BOM costing about the same, at least in Digikey quantities. I am pretty sure I could eliminate a couple more parts at a roughly 10% loss in timing accuracy.

- John

Last Edited: Fri. Aug 23, 2019 - 05:04 AM
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avrcandies wrote:
Actually, how did we survive flux, lead, trichor cleaner, acetone & everthing else that is banned.
Some of you didn't.

"Experience is what enables you to recognise a mistake the second time you make it."

"Good judgement comes from experience.  Experience comes from bad judgement."

"Wisdom is always wont to arrive late, and to be a little approximate on first possession."

"When you hear hoofbeats, think horses, not unicorns."

"Fast.  Cheap.  Good.  Pick two."

"We see a lot of arses on handlebars around here." - [J Ekdahl]

 

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I had almost forgotten about "tricho". I wonder what happened to my can of it from the late 60s. Was a great cleaner for pcbs.

Ross McKenzie ValuSoft Melbourne Australia

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When I was in jr/high school, I etched a PCB in the garage with some ferric chloride in a tray.  Very amazed & happy that it produced my first board, I quickly ran off to the house to build it up.  Maybe a week or 2 later, I want back in the garage & noticed every wrench & screwdriver hanging above was extremely corroded & dripping rust, like they had been recovered from the Titanic.    I made sure that didn't happen again!           

When in the dark remember-the future looks brighter than ever.   I look forward to being able to predict the future!

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valusoft wrote:

sparrow2 wrote:

And you only had to look at them, and they was killed of static :(

On that basis I have to say I must be the luckiest person on the planet. I have NEVER lost a single 4000 series chip handling/soldering thousands of them by hand. I guess YMMV.

 

Never had trouble with that either, though I did not do thousands of them. Once lost some by accidentally touching the 9v battery to the snap the wrong way around. Did lots of projects in high school and junior college with 4000 series "cosmos." Many projects started with a 6.3v transformer, diode, capacitor and add the logic from there.

The largest known prime number: 282589933-1

It's easy to stop breaking the 10th commandment! Break the 8th instead. 

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Torby wrote:
Never had trouble with that either, ...
We (team members) were shown a micro-photograph of the damage to a CMOS device due to ESD that led to the production cessation (IIRC, one skipped a step in a procedure)

The result was another round of ESD prevention training for all.

 

"Dare to be naïve." - Buckminster Fuller

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My first experience was 8bit pic mcu from microchip, well that actually very first time i ever wrote code when started with that.

 

Made a voltage monitor for my car to shutdown amplifiers if voltage did drop below X level, which was adjustable. I had to get the paid version of XC8 to fit the code in the mcu, its funny how the free version insisted that my code takes +100% of space, but the "paid" version said 40% of space used(yes it does bloat the code, or atleast did in past).... needless to say i moved to AVR after that. 

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Talking of old timers, who remembers the 9062?

 

Four legs good, two legs bad, three legs stable.

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gchapman wrote:

Torby wrote:
Never had trouble with that either, ...
We (team members) were shown a micro-photograph of the damage to a CMOS device due to ESD that led to the production cessation (IIRC, one skipped a step in a procedure)

The result was another round of ESD prevention training for all.

 

 

Get regular ESD training here at my new job. Odd that they don't consider bare feet to be adequate contact with the grounded floor mat

The largest known prime number: 282589933-1

It's easy to stop breaking the 10th commandment! Break the 8th instead. 

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There was the fairchild 9602 monostable, as for the 9062, whose chip was that?

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Old timers/monostable - is Mr Brown making puns?

 

Neil

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Kartman wrote:
There was the fairchild 9602 monostable, as for the 9062, whose chip was that?

You're right!
I should have said, "who misremembers the 9062?".

Should have gone with 555. Transposition proof.

Thought it was too obvious, though.

Four legs good, two legs bad, three legs stable.

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Many years ago i had a circuit that used a 74ls123 that would falsely trigger on power-up. A friend suggested using a 9602 - this cured the problem. Was the first and last time i used a 9602.

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Kartman wrote:
... A friend suggested using a 9602 - this cured the problem. Was the first and last time i used a 9602.

I have used the CD4528, CD4538 and CD14538, which were and are, metal gate CMOS one-shots with the same pinout. The latter two address a couple quirks of the 4528.

- John

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