Software Developers View of Hardware - Last Question (2 Viewers)

[Bij]

I did something like this:


1--NOT---AND
2---------/........\
..................... NAND---- Motor
3----------\....../
4----------AND


I think that works

 

[Anthrax]

i just swapped the AND and OR gate from the original around.

i think its right.

can someone double check ?

 

[chaotichampster]

I did exactly the same as Bij and it works for every combination.

I wastn't entirely sure how they were going to distribute 4 marks for it though...

I mean you cant give out 4 marks for just drawing up a logic circuit, unless they were being overly generous.

 

[breesy]

did u all read the question properly ... it said converting all other four-bit signals to 1 ...

It means any combination of other inputs will result in 1, rather than all other input's are 1. Admittedly a bit porrly worded. Seems like a lot of that this test. View of Hardware especially.

I think the client empowerment approach is a curve ball, the whole process indetifying designing implementing etc are part of the 'software development', thus a development approach is perfectly valid... - C

 

[Vex]

Here we go, just threw this together in paint:

You'll find that the last result for 0111 is 0. Highly unlikely there is another mixture that will go through and also output a 0, actually 99% sure there isnt.

Edit: There's yer damn truth table..

 

[haboozin]

You'll find that the last result for 0111 is 0. Highly unlikely there is another mixture that will go through and also output a 0, actually 99% sure there isnt.

you should have done a deskcheck
it was only 16 different possibilities haha..

there will be quite a few different ways of doing this question
i did something similar to the first post (althoguth i didnt change the last gate to like an AND and a NOT instead of NAND for no reason :s

 

[haboozin]

I did something like this:


1--NOT---AND
2---------/........\
..................... NAND---- Motor
3----------\....../
4----------AND


I think that works

bit.................Z.................X
1..2..3..4..Not1 AND 2|3 And 4|NOT(Z and X)
1..1..1..1..0.................1...........1
1..1..1..0..0.................0...........1
1..1..0..1..0.................0...........1
1..1..0..0..0.................0...........1
1..0..1..1..0.................1...........1
1..0..1..0..0.................0...........1
1..0..0..1..0.................0...........1
1..0..0..0..0.................0...........1
0..1..1..1..1.................1...........0
0..1..1..0..1.................0...........1
0..1..0..1..1.................0...........1
0..1..0..0..1.................0...........1
0..0..1..1..0.................1...........1
0..0..1..0..0.................0...........1
0..0..0..1..0.................0...........1
0..0..0..0..0.................0...........1


so thats def right

 

[Vex]

you should have done a deskcheck
it was only 16 different possibilities haha..

Bah fine, go up to the pic and have a look now, heh. I'm way too motivated to see how I went in this exam..(its my band 6 chance, my one and only..)

 

[jarro_2783]

here... look at the shoddy pic.

I did that as well. It looks like there are three answers that work, and that must be an easy four marks.

 

[Vex]

I did that as well. It looks like there are three answers that work, and that must be an easy four marks.

That was a tough 4 marks though, I reckon alot of people would of had a mental block there.

 

[Netterhead1]

1------not---------- nand---
2--------------and/
3-------and/
4------/

i think there are more than 3 ways of doing it. heaps more...

 

[Tim Crockford]

snowboarder

there is also another way where bit 2,3 and 4 go into a NAND gate then meet bit 1 with an OR gate

 

[Mumma]

im in year 11 but you could have easily worked it out using boolean algebra

 

[jarro_2783]

I think you'll find that boolean algebra isn't something anyone actually does unless you decide to look it up and learn it yourself.