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Page: technics-base-circuits-computer_en.htm
Date: 2016.10.19 08:56:29 (UTC+1)
Name: Pk. D
Comment:
I just started work on transferring my "computer" to a set of perfboards. The work is a lot more difficult(and slow) than it seems, but it does help in troubleshooting - I discovered that there was a problem with the connections of the Main Register itself, the key component.( I started with it as it is the easiest to work on, and have progressed no farther than it)
Thanks!
Me: I never said it would be an easy job ;-)
Nice to hear that your project grows.
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Page: technics-base-circuits-computer_en.htm
Date: 2016.09.29 13:12:54 (UTC+1)
Name: Pk. D
Comment:
And you still only provide an that keeps me guessing Let me guess, you mean to say you would use a perfboard?
Me: I told you about the pros and cons - the choice is yours. I think you want to create nothing but a prototype, thus a perfboard or breadboard are best. I prefer soldering.
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Page: technics-base-circuits-computer_en.htm
Date: 2016.09.28 09:44:50 (UTC+1)
Name: Pk. D
Comment:
Thanks, but what would you use, if given the tools required for each of them at the same cost?
P.S. I sent this same comment two days ago. Did you receive it or was the server down?
Me: It's the time needed to create a PCB that makes it unconvenient for a single board rather than the costs.
P.S. maybe I simply forgot to answer that question, too ;-)
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Page: technics-base-circuits-computer_en.htm
Date: 2016.09.25 10:21:52 (UTC+1)
Name: Pk. D
Comment:
Wanted some advice from you :
What would you use for making very complex circuits involving about 20 IC's (and a bunch of resistors, capacitors and transistors) -a perfboard, breadboards or PCB's ?
Me: Breadboard connections sometimes fail and its tricky to find the loose connection in a complex circuit.
Soldering on a perfboard takes more time but is more reliable. PCBs are great, if you have the tools to make them...
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Page: technics-base-circuits-computer_en.htm
Date: 2016.09.20 08:51:49 (UTC+1)
Name: Pk. D
Comment:
As for this statement : "There are two additional buffers on the outputs of the circuit that are not needed for operation, but are often inserted to seperate the output signals from the input signals. " I did not understand what that means. Pls explain "seperate the output from the input signals". Thanks!
Me: If you put a load on the output having low ohmic resistance, the output voltage of the circuit drops. With the output voltage being looped back to the internal circuit logic, that may cause trouble. with that additional buffer there is no feedback to the circuit logic. Even if the load at the output causes a significant drop in output voltage, the logic in front of the buffer still works correctly.
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Page: technics-base-circuits-computer_en.htm
Date: 2016.09.20 08:47:41 (UTC+1)
Name: Pk. D
Comment:
Should have said this earlier, but still, thank you for the circuit, it came of a lot of use in using the logic simulator to try and make a compuer.
As for the "real" one, even the 1-bit version causes some trouble, and I only just started.. :(
Me: It's the trouble that makes you learn what's really going on in electric circuits.
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Page: technics-base-circuits-computer_en.htm
Date: 2016.08.29 11:19:29 (UTC+1)
Name: Pk. D
Comment:
By asynchronous set and reset I mean this:
If Set is pulled high, output Q (/not Q) also goes high (/low) irrespective of the current state of other inputs or the outputs.
If Reset is pulled high, output Q (/not Q) also goes low(/high) irrespective of the current state of other inputs or the outputs.
Rest of the functionality would be same as standard JK flip flop(positive edge triggered), which is there on this page.
Why did you decide to change the page layout anyway?
Me: I have added the circuit to this page. It's figure 26 (refresh the page to see the new version).
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Page: technics-base-circuits-computer_en.htm
Date: 2016.08.28 12:55:02 (UTC+1)
Name: Pk. D
Comment:
Oh, and BTW, I have finally (virtually) built a 8 bit computer out of discrete logic gates.
As for a physical version, the 4-bit one is causing lots of trouble, so I decided to try and build the 1-bit first to improve my (otherwise rather poor) skills at building circuits. My previous question(on this page) came as a result of this attempt.
The new page layout has a problem - you can't directly navigate to any page but have to rely on continuous clicking on nested pages.
Me: Starting it simple is a good idea. It helps for error diagnostics in more complex circuits.
Yes, there are some drawbacks of the new design that I am working on. A new version will go online next week.
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Page: technics-base-circuits-computer_en.htm
Date: 2016.08.28 12:49:37 (UTC+1)
Name: Pk. D
Comment:
Just asking, because I couldn't figure it out myself - What could be the logic circuit for a positive edge triggered JK flip flop with asynchronus set and reset? I couldn't find the answer through google either. Thanks for your help
Me: What is "asynchronous set and reset" for you?
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Page: technics-base-circuits-computer_en.htm
Date: 2016.01.09 at 19:17:56 (UTC+1)
Name: Your banner
Comment:
I would change it to be-
`Learning' is the most powerful weapon we can use to change the world.
It's not possible to teach or to educate. However. it is possible to become educated. Teaching and educating are `external', whereas learning is `internal'.
Also, the only change the world needs is to be left alone by the civilized -- in the same way it is left alone by all living creatures, including not-civilized human beings.
Me: Thanks for your comment. I found that quote from Nelson Mandela as it is, thus I won't change that. Maybe Nelson had the same problems with the subtleties of English as I have...
...at least this planet will be left alone in some billion years as the sun grows to a red giant...
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Page: technics-base-circuits-computer_en.htm
Date: 2015.12.13 at 15:56:32 (UTC+1)
Name: Pk. D
Comment:
I found the solution to my problem.
Instead of using pull down resistors (as I earlier did), I used pull up resistors at the inputs - and it worked!
And, as a start a "virtual" 1-bit computer is ready on a logic circuit simulator, and it works.
Thanks for all your help so far (previous about 1 year).
Me: You're welcome!
Sometimes internal pull up or pull down resistors of a device can cause trouble as yours. Defenitely something I will have to consider when creating future chapters about physical computing or logic circuits.
Considering continuous speed in your computer evolution, it is a long way to get a 64bit computing machine ;)
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Page: technics-base-circuits-computer_en.htm
Date: 2015.11.30 at 09:34:09 (UTC+1)
Name: Pk. D
Comment:
I wish to ask how to use 7447 IC successfully.
I have wired it according to the data sheet.
Yet, all its output continually output LOW.
Thanks!
Me: 7447IC where have I used one? Or is it your own project and what do you want to do with the chip?
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Seite: technics-base-circuits-computer_ge.htm
Datum: 2015.11.16 um 19:35:53 (UTC+1)
Name: Mark
Kommentar:
Hallo
Wo bekommt man günstig diese Bauteile die sie verwenden. Würde mich sehr interessieren. Gibt es auch günstige Einsteigersets mit Basisbauteile zum Anfang von Elektroniken Schaltkreisen.
Ein Link oder Produktname würde mir schon sehr helfen.
Danke
Me: die ICs sind bei so reichlich allen Online-Elektronik-Händlern zu beziehen. Ich kaufe da, wo ich's gerade finde. Die Bezeichnungen der Chips habe ich auf der Seite angegeben. Wenn was fehlt, "Bescheid" sagen.
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Page: technics-base-circuits-computer_en.htm
Date: 2015.08.15 at 18:20:36 (UTC+1)
Name: Pk. D
Comment:
I am going to build a simple 4-bit 'computer' out of just the components listed here(and few others).
So, what 16 byte RAM chip and 4 byte RAM chip do you recommend?
I have already made the adders, subtracters and digital comparators, besides the GPIO unit.
My first step is to build the ALU, as I've already made most of the essential components.
In around 6 months, it should be ready ( I don't have hours of free time everyday after all due to school :) ).
I will be asking you for more help soon
Me: This is a very ambitious project. I have never played with RAM chips, thus I can't give an advice what ICs to buy.
Have a look at that homebrew CPU:
http://www.homebrewcpu.com/
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Page: technics-base-circuits-computer_en.htm
Date: 2015.08.15 at 09:12:32 (UTC+1)
Name: Pk. D
Comment:
Which positive edge triggered D-flip flop do you use?
Me: CD4027BE SN74HC74N is the type I have used in the video.
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Page: technics-base-circuits-computer_en.htm
Date: 2015.07.03 at 13:39:50 (UTC+1)
Name: Pk. D
Comment:
BTW , if I ever buy T flip flop ICs , which should I look for?
Me: I have used CD4027BE positive edge triggered JK flip-flops.
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Page: technics-base-circuits-computer_en.htm
Date: 2015.07.03 at 13:38:12 (UTC+1)
Name: Pk. D
Comment:
That is a total of 18 Transistors and at least 26 Resistors.
Me: ...or just 9 transistors, 16 diodes and 17 resistors. Note that the most simple NAND gate with 2 diodes and two resistors uses a MOSFET.
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Page: technics-base-circuits-computer_en.htm
Date: 2015.07.01 at 19:06:28 (UTC+1)
Name: Pk. D
Comment:
Isnt there any simpler way of making a T flip Flop with logic gates?
I am making them with transistors alone, so please help me as it is very tedious process.
The current version requires a total of 20 Transistors at least.
I cannot find a T Flip Flop in any nearby shops, so have to make it with transistors alone.
Me: Even if it sounds simple, it isn't. If speed doesn't matter you can compose a T flip-flop with two relays.
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Seite: technics-base-circuits-computer_ge.htm
Datum: 2014.09.06 um 22:10:15 (UTC+1)
Name: Bert
Kommentar:
Heftig, so viel Wissen auf einmal!
Einmal durchgelesen, und schon versteht man die ganze digitale Welt!
Reife Leistung Norbert!
Viele Grüße, Bert
Me: Danke!
...noch hab' ich nicht die GANZE digitale Welt erklärt, aber ich arbeite daran ;)