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.

If you don't know my whole story, keep your mouth shut.

If you know my whole story, you're an accomplice. Keep your mouth shut. 

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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

If you don't know my whole story, keep your mouth shut.

If you know my whole story, you're an accomplice. Keep your mouth shut. 

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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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"Dare to be naïve." - Buckminster Fuller

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"Dare to be naïve." - Buckminster Fuller

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A bit late to the dance...

 

Mine was RCA 1802. You basically had to key in the program, one instruction at a time. That was not that different from the PDP8/ASR33 (?) that I played with about the same time. Just manual instead of punched tape. Never built a complete project with it :=(  

 

Much later, there was 8051. Did LOTs, all assembly language.

 

Jim

 

Until Black Lives Matter, we do not have "All Lives Matter"!

 

 

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ka7ehk wrote:
Mine was RCA 1802.
Likewise immediately after college via a cross-assembler on a DEC PDP-11/34 (edit: maintenance of BIT on dual 1802 with dual-port RAM)

Today and if one's so inclined on the Atom editor (edit, link to the cross-assembler)

https://atom.io/packages/search?utf8=%E2%9C%93&q=keyword:1802

 

"Dare to be naïve." - Buckminster Fuller

Last Edited: Tue. Aug 4, 2020 - 12:08 AM
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Mine was RCA 1802. 

Maaaann...  That wan't the first processor I used, but CDP1802 was the first I used a lot for an extended interval...knew every microscopic aspect of that chip, like a walking timing diagram & opcode lookup table in your head. We bought some expensive logic analyzer & I was "in charge" of learning all about it.  For fun, we were shooting paper clips in the lab & one zoomed right into the slots....we about dropped our drawers & to rip it apart, hoping for the best...got verrry lucky.

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

Last Edited: Tue. Aug 4, 2020 - 12:33 AM
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I lived in a small town in S.C., and the only place to get anything electronic was the TV repair shop. (yeah, they still had those)  Go in and ask for a Z80, and they'd look at you like you had three heads.   Other than being a microprocessor, I didn't know much about it, but I wanted to know everything about it.   (the Popular Electronics aritcle on building the ELF, got me started, but I never built it, I have the plans and most of the parts, so maybe one day..... another unfinished project)

It took a long time, I figured there was some sort of conspiracy to keep people from learning about microprocessors. (no internet had not been available yet).  I finally started working at a medical electronics company, and worked with a guy that had the same interest in micros, and the same problems.   Never did get far, we just couldn't find good information.  Like what the heck is the "stack" and where the heck is it?  Drove us crazy.

I wanted a Sinclair "build it yourself" so bad, but just couldn't get one.  Plus, they had custom chips, so it wouldn't have done me much good.

Then I found something called the "MMicroprofessor".   Still have it.  (plus two more!)   Single Z80 board, 7 segment display, cassette interface.   By then I had tons of data books (still have most).  I worked with that thing day and night.   Built a EPROM programmer to go with it, built a speech processor using the SPO256 (still have that and several other boards/chips), and LED "graphics" displays, all kinds of stuff.

 

I never looked back.   In those days, I couldn't get stuff.   Now I can't let stuff GO!

 

 

Just gettin' started, again....

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clawson wrote:

My most thumbed book was a copy of the Z80 opcodes but sadly I cannot find a picture of it online (and my actual copy must be hidden in a box in my loft these days) but in searching I was reminded of:

 

 

The Zaks book about Z80 was the "bible" in the same sense that K&R was/is to to C!

 

You mean this one? 

 

Or the little one (maybe 5"x 5")?   I had this one downstairs, I thought the smaller ones were there among the other Z80 books, but didn't see them.  I saw some of the small ones on eBay I think it was, for something like $45 each.

Just gettin' started, again....

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Apropos of nothing at all, my 6502 emulator has sprung to life. It doesn't pass the standard emulator tests yet - something in the rather odd handling of the break bit (which apparently doesn't actually exist in the status register but is generated on the fly - still trying to work that out - and it doesn't do a proper reset or interrupts yet, but it's usable.

 

Works on both Linux and Windows, though is five or ten times faster on my slower Linux machine... I suspect that the windows debugger or the text terminal is the culprit as the code shouldn't be massively different...

 

Note: the 'b' option is not yet implemented. The virtual machine contains 16k of ram from 0-0x3fff and 16k prom from 0xc000-0xffff - feed it an intel hex file that fits in there and see what breaks - probably plenty.

 

Neil

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Last Edited: Tue. Aug 4, 2020 - 06:38 AM
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"Dare to be naïve." - Buckminster Fuller

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"Dare to be naïve." - Buckminster Fuller

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I still know way too much about these computers. I built a floppy disk controller and ram upgrade for these at a spotty young age.

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My first personal computer was the Radio Shack MC-10, a "BASIC trainer" with a Motorola 6803.  For $50 in 1984.  There was no internet and it was very difficult to get beginners information on the subject of microcontrollers and personal computers. Then, like everyone else, I got a Commodore 64 in 1986.

 

Finally a PC in 1989;  Turbo C in 1991,  an AVR assember in 1998, and an Arduino in 2014.  Currently I'm trying to get the Arduino UNO to "provide the utility" of a Commodore 64 since they are both on the same technology level.   Except for the cost:  a Commodore 64 "system" would set you back about 100 hours of Minimum Wage Units  (meaning you had to work about 100 hours at min wage to buy one).  Currently an Arduino system will set you back about 0.3 to 0.5 hours worth of Min Wage Units, which is several orders of magnitude of performance-for-price increase.

 

In 1975, a professional-level Intel 8085 Microprocessor Bond-Out-CPU development system with software, support, and training would cost about $30,000.  Forty-five years later, an Atmel/Microchip ATTiny10 (which is rather roughly about the same as the 8085 in general computing power) costs $0.30, with internet-based software, support, and training.  But the complexity of the ICs is about the same.

 

This is really bad for STEM workers like electronics technicians because a tech company will invest thousands of dollars and hours in the training and support of electronic engineers and embedded-system programmers for a skilled (and profitable) operator of a $30,000 development system.   But no company will invest anything to train or support an employee to productively use a 30 cent IC.  STEM workers are expected to learn everything on their own: either through long hours of unfocused web-based research (like YouTube video watching) or expensive unfocused electronic engineering University classes (where you are expected to learn advanced Calculus along with anything useful to a prospective employer).  

  STEM sucks as a career, especially embedded systems programming.  For a high-IQ individual, it has the lowest financial return for the amount of time invested in mastering the complex and ever-changing details of the profession.  The only people who succeed and prosper are the few who have the "nerd" personality disorder that prevents them from a career in the legal, medical, or financial fields, and the raw intelligence to absorb and retain twice as many technical details as all the other people with "nerd" personality disorder.

   Were it not for the constant order-of-magnitude performance-over-price increases, embedded-systems programming would have died out back in the 1980s.

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Ah the SDK-85, I remember her well!

I recall adding the edge card connectors and jumper needed to make an S-100 bus slot so more memory ram and rom could be added to the system.

Not to mention more power supply to support the card slot(s).

 

Jim

 

 

(Possum Lodge oath) Quando omni flunkus, moritati.

"I thought growing old would take longer"

 

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valusoft wrote:

Joey, I was going to post a photo of my copy of Lance's book, but couldn't lay my hand on my camera fast enough.

 

I still have my Leventhal , but it's black & green , not yellow

 

Had a DIY (Solder) 6800/6809 system "Swedish CÅ System"  finished in 81' - Running Flex w. a whopping 48+8K Ram.

 

Before that i used a Moto D2 kit

https://en.wikipedia.org/wiki/ME...

 

 

/Bingo

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I built a Sinclair ZX81 as a teenage electronics hobbyist, decided I preferred computing, and spent a career with datacentre-scale systems. They are basically very boring, as they do nothing tangible other than consume electricity, flash LEDs, and create noise and heat ;) I did enjoy working with robotic tape libraries for a few years, and you could always amuse yourself playing with (very slow) sorting algorithms.

 

I came back to hobby electronics a few years ago and discovered Arduino. It's a remarkable time to be an electronics hobbyist compared to 40 years ago. My teenage self would be amazed by the variety, capabilities and costs of current technology, although most AVRs have the same RAM as my first computer !

 

STEM teaching is a world away from my experience at school, where 'computing' was punched cards sent away somewhere, with the results a couple of weeks later on reams of music-ruled paper.

 

With the industrialisation of commercial computing (i.e. cloud), it's no longer a career I'd recommend unless you can develop a niche skillset as a consultant/contractor, or are commercially-minded and find money more interesting than technology.

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In 1975, a professional-level Intel 8085 Microprocessor

It don't match!

either 8080 or at least 1976 

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With 8085's you didn't need a bond-out. Maybe the 8048? or 8021??

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