I think he has already left this forum

He hasn't replied now so I assume he knows his stuff. I guess

 

I'm not asking if you know how to make it.. we can help with that if you actually provide the information
But YOU need to tell us exactly what you are trying to make and how it needs to function..

So far I can answer your question with the following solution..
Take 5 pieces of paper..
Write 9 on one, 7 on the other, 5 on another, 3 on another and 1 on the last
Staple them together in order with 9 being the first (on top) and 1 being the last piece of paper (on bottom)..
Voila.. a down counter.. Just flip through the pages to count down..

Now this is along the lines of what we expect..
---------------------
I'm working on a school project where either I'm not paying attention at all or the teacher is sleeping all day long
I need to create a count down counter..
It needs to start at 99 and count down in odd numbers ending at 1..
Each number corresponds to the number of seconds left.
I need the count to display on 2 small 7 segment displays
I need the count to start when I press a start button and reset to 99 whenever I press a reset button
When it gets to 1 it should wait until I press the reset button
I cannot use a microcontroller

I laugh so much when i see this hahah

 

He hasn't replied now so I assume he knows his stuff. I guess

As has been pointed out to me by others... The ones who know their stuff don't come here asking for help. The ones who do fall into a couple categories. Those who just need a little guidance and those who are struggling.

 

As has been pointed out to me by others... The ones who know their stuff don't come here asking for help. The ones who do fall into a couple categories. Those who just need a little guidance and those who are struggling.

True. Still I am quite curious on his current progress.

 

As has been pointed out to me by others... The ones who know their stuff don't come here asking for help. The ones who do fall into a couple categories. Those who just need a little guidance and those who are struggling.

There's another big category -- those that simply want someone else to do their work for them. Sometimes those people come around, but more often they just leave when they realize that they are actually expected to put in some effort, too.

 

I'm sorry because i feel bad for not being able to construct such a simple circuit. But now I already know what to do. I used 4 bit binary counter, inverter and XOR.

 

No apology necessary. You can only start from where you are.

 

I used 4 bit binary counter, inverter and XOR.

Care to post your solution?

Trying to use a standard binary counter would require a lot of glue and it would have glitches every time you tried to skip an even count.

 

Care to post your solution?

Trying to use a standard binary counter would require a lot of glue and it would have glitches every time you tried to skip an even count.

Why?

Look at the following sequence (three bits for convenience)

111, 101, 011, 001

What is the logic that can generate the lsb?

If you have a binary down counter, what needs to be added to it to create all the rest of the bits?

 

Why?

Too early in the morning and I wasn't thinking outside of the box