Computer Science Help

[Darth Hideous]

Hey guys,

 

So I'm taking a computer science course at university and am falling behind slowly on logic gates (OR, AND etc) and truth tables etc. Was just wondering what resources you guys use for help with computer science related problems? Or if anyone can help out 

 

Thanks!

[Ciccioo]

with logic gates, you just have to understand them, i mean they are... logic. and they are gates

if you spend time looking for a fancy software that does tricky things to make it more fun, i don't know... i think you're wasting time

you can just spend 5 minutes with a piece of paper and a pen doing a couple of examples

 

i mean...

if a girl is hot OR she is rich, then try to marry her

when should you marry her? when either the first condition OR the second OR both are true

if a girl is hot AND she is rich, then try to marry her

if you're so pretentious, you only marry her if she is both rich and hot

 

write every possible combination of richness and hotness and the related result, and you're done

[Darth Hideous]

with logic gates, you just have to understand them, i mean they are... logic. and they are gates

if you spend time looking for a fancy software that does tricky things to make it more fun, i don't know... i think you're wasting time

you can just spend 5 minutes with a piece of paper and a pen doing a couple of examples

 

i mean...

if a girl is hot OR she is rich, then try to marry her

when should you marry her? when either the first condition OR the second OR both are true

if a girl is hot AND she is rich, then try to marry her

if you're so pretentious, you only marry her if she is both rich and hot

 

write every possible combination of richness and hotness and the related result, and you're done

Haha very clever, if only gay marriage was legal in Australia    I understand the logic gates, just having issues converting to NAND only schematics and stuff like that. Maybe help for general computer science. 

[Ciccioo]

for that kind of conversion you pretty much just need to remember the equivalents

 

the NOT is straight forward, you just have one input A in both inputs and it comes out as NOT A

A NAND A = NOT( A AND A ) = NOT A

the AND is just a NAND with a NOT after it, because

NAND = NOT AND

so

NOT NAND = NOT NOT AND = AND

for the NOR you need to keep in mind De Morgan's laws, so

A NOR B ------demorgan------> (NOT A) AND (NOT B)

you already know how to do NOT and AND, so you can just substitute and get the result

 

 

similar process for the OR

A OR B = NOT( NOT ( A OR B ) ) -------demorgan-------> NOT( (NOT A) AND (NOT B) ) = (NOT A) NAND (NOT B)

if you write those down using the nice boolean notation it will be way more clear to see how those relationships work

[Darth Hideous]

for that kind of conversion you pretty much just need to remember the equivalents

 

the NOT is straight forward, you just have one input A in both inputs and it comes out as NOT A

A NAND A = NOT( A AND A ) = NOT A

the AND is just a NAND with a NOT after it, because

NAND = NOT AND

so

NOT NAND = NOT NOT AND = AND

for the NOR you need to keep in mind De Morgan's laws, so

A NOR B ------demorgan------> (NOT A) AND (NOT B)

you already know how to do NOT and AND, so you can just substitute and get the result

 

 

similar process for the OR

A OR B = NOT( NOT ( A OR B ) ) -------demorgan-------> NOT( (NOT A) AND (NOT B) ) = (NOT A) NAND (NOT B)

if you write those down using the nice boolean notation it will be way more clear to see how those relationships work

Ah, sweet. Thanks for the help