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Topic: Where did you start with Micro controllers? (Read 8248 times) previous topic - next topic

AWOL

KIM was 6502.
The Motorola device is a MEK6800D2.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

Benji

First computer: AT&T MSX
Second computer: 8088, later replaced by an 8086 with a *gasp* hard drive
Then, on the a 80286, 80486 DX4-100, pentium 75, pentium 3, since then AMD's and since 2 years a macbook.

Programming? Well, that's a different story. I wasn't too good at it. I was doing computer science in school, but I got sick, so I missed a lot of the classes. Pascal was pretty ok for me, but besides that I didn't really follow the instructions and the books where horrible.

I gave it up for a long time, but then I wanted something to tinker with, someone prescribed me Arduino and since then I am hooked.
That's about a year ago.

focalist

#32
Feb 07, 2012, 10:48 pm Last Edit: Feb 07, 2012, 10:52 pm by focalist Reason: 1
Arduino certainly is good for what ails you.. Or at least provides an interesting distraction from feeling like crap...  :smiley-mr-green:  

I think you chimed in on that 'Arduino as therapy' thread I started last year sometime, didn't you?

http://arduino.cc/forum/index.php/topic,61970.0.html
When the testing is complete there will be... cake.

retrolefty

#33
Feb 07, 2012, 11:43 pm Last Edit: Feb 07, 2012, 11:49 pm by retrolefty Reason: 1

As I recall, the NCR Century 200 computer I worked on had a row of bulbs (not LEDs) on the front panel. It think there were around 16, and the operator manual stated that if there was an error, the computer would stop and the error code could be determined by examining the "number" in the bit patterns of the lights.

Thankfully my employer had also invested in a state-of-the-art teletype (the sort that you put a typewriter ribbon in, and you put fanfold paper through with holes punched along the side), and the teletype would helpfully spit out a more informative message, like:

Code: [Select]
5100 INOPERATIVE

Although you usually could operate "by ear" as if the job was printing a huge number of statements on the line printer (the fast printer), which made a terrific racket, and the printer suddenly stopped, you would then hear the teletype pathetically typing away in the background "5-1-0-0-I-N-O-P-E-R-A-T-I-V-E" which took about 5 seconds.


I spent a lot of time repairing and working on those large 132 column line printers. At the time in the mid 70s I noted that the line printer model I worked on cost more retail then the 3 bedroom house in the 'burbs' I had just bought. The main print drum was engraved in Switzerland. Doing a print hammer alignment (all 132 of them) took just as long and painful as having a root canal done. And the two spindle disk drive (50 megabytes each) was the size of a refrigerator and cost like $50K. The blank removable disk cartridges were $1,200 each.

Lefty

ajofscott

In highschool I got to scavenge 3 Borroughs Terminals, was a tinker's dream! Huge CVT and 6 2 device TO-3 heatsinks, loads of cards all descrete and small glue logic ICs. The card edge connecters were all wire wrapped connections, a true work of art.

Nick Gammon

Yeah, you don't see printers like that any more. For anyone that hasn't seen one, there was a drum of 132 letters engraved side-by-side (so all possible letters are in a column vertically, and there were 132 of them horizontally). The drum span at high speed and as the paper was pulled past it 132 little hammers fired at exactly the right moment to hit "A" (rather than "B" or "C") to print an entire line at once.

I think for simple reasons of space they only had upper-case letters, which is why old computer printouts were in all upper-case.

They were precision devices, and if they went wrong, well the print-out was hard to read. :)
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

retrolefty

Quote
They were precision devices, and if they went wrong, well the print-out was hard to read.


Yes, the final test was to print lines with all the same characters and look to see if there was an indication of wavy lines being printed. The adjustment had one hooking a scope probe to the channel one hammer as the reference, using a very small counter EMF pulse that indicated the hammer had struck the drum, then you moved the channel two scope probe one at a time to each of the other 131 hammer circuits and mechanically adjust the hammer's starting position such that it's pulse matched hammer #1. All the while the print pattern was printing the identical character on all 132 positions at the same time, it sounded like the loudest machine gun firing none stop, and made the overhead lights flicker when firing. To this day my poorer hearing in my right ear I blame on that adjustment procedure. That or it was the ear facing my starter wife when I was trying to go to sleep.  ;)

Osgeld

well with computers I started twiddling bits using my apple II and then later an XT ... with micro controllers my first was a PIC32 which I promptly plopped stickOS basic on, which is what I still use on it today
http://arduino.cc/forum/index.php?action=unread;boards=2,3,4,5,67,6,7,8,9,10,11,66,12,13,15,14,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,86,87,89,1;ALL

Jack Christensen


I spent a lot of time repairing and working on those large 132 column line printers.


There were stories about programs that could play tunes on line printers by printing different combinations of letters. Never got to see (hear) one. Those things were beasts.
MCP79411/12 RTC ... "One Million Ohms" ATtiny kit ... available at http://www.tindie.com/stores/JChristensen/

shadow13

I started about six years ago with a PICkit and it wasn't bad but it was sort of awkward to use. Some years latter I tried the tower system by Freescale but that was pretty complicated. So a few weeks ago I got a Duemilanove with the 328 and I look forward to putting it through its paces.

jimfah

4004 4-bit computer.  I forget the speed.  1976?

We used to program it with eproms  (16k bit).  I remember patching them and paying attention whether the patch would raise or lower bits.  You could always lower a bit - and therefore reuse an eprom with enough bits set.

Sigh.  Those were the days.

Jim

westfw

Quote
I think for simple reasons of space [line printers] only had upper-case letters

Of the two (local) mainframes that I used in college, one's line printer was upper-case only, but the other had both upper and lower case.  We evaluated a "Printronix" printer at one point; it was sorta neat.  Rather than printing a line of characters, it would print a line of dots (dot-matrix style, but a WHOLE LINE), so it could do graphics as well as text.

Hmm.  I wonder what a modern high-speed printer looks like these days?  Most of the places I've worked have "distributed" their printing (at least, the user-visible printing) to as many relatively slow printers as required, and of course a modern laser printer spits out pages at fixed speed regardless of print density, so they aren't nearly as entertaining as the old line printers...


retrolefty

#42
Feb 14, 2012, 01:33 am Last Edit: Feb 14, 2012, 01:36 am by retrolefty Reason: 1
Quote
Hmm.  I wonder what a modern high-speed printer looks like these days?


The last I saw, but didn't work on, were large laser based monsters using similar method as copy machines use. Print image on light sensitive plate or drum with laser, apply toner to charged plate and transfer to paper, then heat to set toner. That would allow a lot higher speed and full graphics capabilities. I suspect the speed limit is how fast one can move paper through the printer.

I suspect whatever tech the newspapers are using these days to print their papers is what is state of the art in high speed printing. I suspect the days of setting lead type is long gone.  ;)




Nick Gammon

#43
Feb 14, 2012, 01:35 am Last Edit: Feb 14, 2012, 01:39 am by Nick Gammon Reason: 1
Printronix rings a bell. I think you are right, they had a line of dots which buzzed away as the paper passed them.

As far as I have seen (and this was a little while back) they1 have very fast laser printers. There was also a technology, whose brand name eludes me2, where they put toner on the page but just used very high pressure to fuse it to the page. (Looks like the technology is called Ionography).

1. High-speed production houses, like banks, insurance companies.

2. Miltope, maybe.





Also I believe they print "packing information" onto the side of each page of the letter (look at the bar code on the edge of a recent statement). This tells the envelope-insertion equipment how many pages go into one envelope (eg. for a multi-page bank statement).
Please post technical questions on the forum, not by personal message. Thanks!

More info:
http://www.gammon.com.au/electronics

retrolefty


Printronix rings a bell. I think you are right, they had a line of dots which buzzed away as the paper passed them.

As far as I have seen (and this was a little while back) they1 have very fast laser printers. There was also a technology, whose name eludes me2, where they put toner on the page but just used very high pressure to fuse it to the page. (Looks like the technology is called Ionography).

1. High-speed production houses, like banks, insurance companies.

2. Miltope, maybe.





Also I believe they print "packing information" onto the side of each page of the letter (look at the bar code on the edge of a recent statement). This tells the envelope-insertion equipment how many pages go into one envelope (eg. for a multi-page bank statement).


Printronix did make one the earliest 'dot matrix' printers in 132 column version. Dec also made an early 132 column dot matrix for their minicomputer systems, the famous LA-36 printer. Later Epson used the same method for small printers for the early microcomputer systems, followed by many that made dot matrix printers the first popular affordable printers for home PCs. They sure made a piercing sound and I soon learned to hate dot matrix printers because of that.

Lefty

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