You don't need an adder or anything fancy, just basic gates AND, OR, NAND etc.

The functions I talk about will look at all 3 registers at the same time. For example, F1, that will check for a 3, will look at all registers for an ace. But you can save yourself some circuits with a little thought. For example, F3 that will look for a 3, only needs to look at the first register, as any potential 3 will come through it first.

 

is this something like this? first AND will look for 11, second look for 10, 10 and last will look for 01,01,01..I need your comments.. thanks

 

this is my final memory system..could you give some comments, whether there's connection error?

 

Ok, first of all, you need 3 gates to detect the 2's in case something like 212 comes. You need to look at a span of 3 numbers. Also, you should actually include the inverters too. A single AND gate will give 1 for an input of 11 which is 3. If you want to detect 2 you need to invert the LSB going to the AND gate.

Also, if you plan to use IC's with a clock, that clock must be used. The IC's won't work if you leave the clock hanging (like in the 7474) or if you have it constantly on High (like on the 74194). You need to hook up the clocks on the "enter" button in series with an SR latch in order to operate them, and leave the "activate" pin ON constantly.

Please revisit your two above circuits.

 

how should I build the AND gate for the case 212?? is this something like this?

 

need your comments sir..

 

I wanna ask something, I have a doubt like this, say for example first input should go to function 1 to check for a 3, and immediately declare pass, if it's true, if not then enter another value...etc etc

so, in building my circuit, I have to connect the output of a first register immediately to function 1 right?? if not (use an inverter) then output of function 1, go to the input of register 2? *this one I'm not so sure*

I hope you don't mind to entertain my silly question, tho I'm very slow leaner, I wish I could finish this project and do my best at least

 

Look, I 'm gonna be honest with you. What you are asking is actually to teach you how to drive a race car, when you don't yet know how to ride a bicycle. The problem you want to tackle is way above your level of knowledge. Consequently, if we want to help you, coaching you with hints and remarks won't do you any good. What you need is a full-time teaching, and that can be very tiresome through consecutive posting. I could design this circuit, but it would still take many hours to draw and debug.

I will suggest you once again to drop this project for now, and focus on raising your knowledge level. If you are really interested on digital electronics I suggest M. Mano's "Digital Design" hands down.

If you still want to continue on this thread, I will try to keep answering, but I will do so only when I have the time needed to write comprehensive and instructive answers.

 

but, this one is part of my assignments.. I don't have any other choices except to do it.. so any helps I really appreciated