A D-latch is significantly different from a RS-NOR latch. An RS-NOR will retain a 1 as output if at any time the input was 1. It doesn't matter if it was 10 years ago or 1 millisecond. A D-latch ONLY updates it's output when the clock signal is on. Just build a RS-NOR and a D-latch and compare the difference.
This is important because you want to store data in the latches. And calculating that data is not instantaneous. The inputs will flicker and display wrong values before it stabilizes. If you use RS-NOR latches these flickers will corrupt the data in your register. That's why we use D-latches, they won't be corrupted during the flickers. And when the output is stabilized we can send a signal to the clock input of the D-latches to neatly update them all to their final value.
A RS-NOR basically is this:
Output 1 = R NOR(1) Output 2
Output 2 = S NOR(2) Output 1
Assuming Output 1 is already on, the signal will go to NOR(2) therefore making output 2 off.
Say we put a signal on R, since there is no signal from either R or Output 2, it would be inverted and make Output 1 on in the first place.
Once we apply the signal, 1 will be off and then since 1 off, there will be no more on inputs on NOR(2), which makes 2 on.
EDIT: Nevermind, this .gif explains it better than me ^^
A DFF is much much different. Its basically 1 bit memory by itself. The output will never change state unless there a signal on the write input.
EDIT 2: Wow, I don't remember how long ago I have tried to make a calculator, I got bored and went on to pursue creative redstone. I have learned alot, more than enough to make a calculator, but you have got my will back to make one. Thank you.
Alright considering both of your posts. I don't see the problem with an RS NOR Latch. Isn't it just possible to store data in the RS Nor Latch with pistons or something until the final value has been reached?
and
about the memory cell... isn't an RS NOR Latch a memory cell too? I still don't see the most clear different between the two.
Excellent! Hoping this thread isn't a dying thread. I keep on forgetting it exists and go away for ages doing other minecraft stuff and completely forgetting about the forums... =/
Don't let it die I love to check on it firstly all time
Someone give me a good subtracter design, I tried adding an inverter to the Cin of an Adder but I wasn't sure if that was going to work.
Sancarn, Ralath0n?
It's actually simple to make an adder into a subtractor, just invert B and +1 to Cin.
Course you can make it conditionally invert the B by using XOR gates to determine whether you would want to invert or not.
It's actually simple to make an adder into a subtractor, just invert B and +1 to Cin.
Course you can make it conditionally invert the B by using XOR gates to determine whether you would want to invert or not.
So in a full Adder, I keep Cin on at all times for subtraction and attach an inverter to one of the two inputs of the adder?
Right that is subtraction only power Carry in and invert any one of inputs
I was experimenting around and I got it working with 1 inverted input of each adder and an inverted output of each adder. Now I am trying to add the subtracters into the calculator I made earlier.
__________________________________________________________________________________________________________
Sancarn, what do you think I should study next? I am not sure if Multipliers and Dividers are that important.
I was experimenting around and I got it working with 1 inverted input of each adder and an inverted output of each adder. Now I am trying to add the subtracters into the calculator I made earlier.
__________________________________________________________________________________________________________
Sancarn, what do you think I should study next? I am not sure if Multipliers and Dividers are that important.
Ralath0n feel free to add!
DarkVegito,
You can put stack of adders on other stack of adder like vertical stacking. Inputs should be not problem because Glowstone can bring redstone power to all the way up vertically. If you want completely calculator then you can learn about Multiplier and Divider. But for the computer I'm not sure lol
You can put stack of adders on other stack of adder like vertical stacking. Inputs should be not problem because Glowstone can bring redstone power to all the way up vertically. If you want completely calculator then you can learn about Multiplier and Divider. But for the computer I'm not sure lol
Thx for the tip, I am guessing the stacking would help if someone wants to make a large bit calculator.
Ralath0n, what did you say about putting an XOR gate before an Adder to make multi-functional (Adder and Subtracter), So for that do I just put an XOR gate before one of the inputs of the Adder and power the XOR when I need subtraction mode? Something like that?
So if i want use that function like OR, or AND, etc. Then I would use multiplexer to choose the path that I want this function to be active. But ALU functions can be many or all of it? Also i noticed that multiplexer can be used in Division for like shift and subtract or restoring division I think. So if you know how to add multiplier and division to ALU is that a function or it is not function of ALU?
I just read part of this thread and I am surprised that no-one seems to know that if you look up the 4000/4500 series or 7400 series of integrated circuits they will show a block diagram of what's inside.(spec. sheet) you then use their design and convert it to redstone. this series of ic's is old, back when they couldn't fit much on a chip so they're pretty simple.
Alright considering both of your posts. I don't see the problem with an RS NOR Latch. Isn't it just possible to store data in the RS Nor Latch with pistons or something until the final value has been reached?
and
about the memory cell... isn't an RS NOR Latch a memory cell too? I still don't see the most clear different between the two.
In a RS-NOR, you can interchange them with either input.
Does that make a difference? Can you give me an example where a DFF is compulsory and an RS NOR Latch would never work?
I will go through rest of your post after I understand this inverting part of subtraction.
OK for this part, How would for example a calculator would know that 1111 is supposed to = -1 because normally it would equal 15?
I personally think that experimenting helps a little more for me. So what subtracter should I make?
So i will use that to put all the logic and see how it works.
Don't let it die I love to check on it firstly all time
Sancarn, Ralath0n?
It's actually simple to make an adder into a subtractor, just invert B and +1 to Cin.
Course you can make it conditionally invert the B by using XOR gates to determine whether you would want to invert or not.
So in a full Adder, I keep Cin on at all times for subtraction and attach an inverter to one of the two inputs of the adder?
Right that is subtraction only power Carry in and invert any one of inputs
I was experimenting around and I got it working with 1 inverted input of each adder and an inverted output of each adder. Now I am trying to add the subtracters into the calculator I made earlier.
__________________________________________________________________________________________________________
Sancarn, what do you think I should study next? I am not sure if Multipliers and Dividers are that important.
Ralath0n feel free to add!
DarkVegito,
You can put stack of adders on other stack of adder like vertical stacking. Inputs should be not problem because Glowstone can bring redstone power to all the way up vertically. If you want completely calculator then you can learn about Multiplier and Divider. But for the computer I'm not sure lol
Thx for the tip, I am guessing the stacking would help if someone wants to make a large bit calculator.
Ralath0n, what did you say about putting an XOR gate before an Adder to make multi-functional (Adder and Subtracter), So for that do I just put an XOR gate before one of the inputs of the Adder and power the XOR when I need subtraction mode? Something like that?
DarkVegito,
Also for the Multiplication/Division, thanks for googling and i might think like to add to seperate ALU like only Mult/Divi and only ALU like together