Help me with implementing a logic calculator

[MSRA]

I am trying to implement a calculator which takes input via keypad or any other way like switches etc decode it into binary numbers via decoder ic perform airthmetic calculations(add,sub,mul and division only) and display the result on either 7 segments or on LCD.
but so far what i hav is idea of how it should be and not any thory articles related to it and idea of how to implement it.
i want to take input in decimal form ,from 0-9 calculate it and display the result which i may restrict to 2 digits(less than 100).

i hope u will understand what i said and will try to help me to solve this...

 

[Ajish Babu S]

ic 74147 keypad encoder

Hi

8051 micro controller may used for this project.
Using 8051 micro controller you can easily interface by keypad.
According to your application you can perform addition, subtraction, multiplication, division e.t.c by built in instructions or simple algorithms.
LCD is a best option for outputting. LCD display is easily interfaced with 8051 micro controller.

All these operations independently explain most of 8051 books.

My suggestion is 8051 micro controller by Mazzidi is quiet simple.

If you want more help ask here.

With regards
Ajish Babu S

 

[MSRA]

Re: logic calculator

thanks...
but i am restricted to not use microcontroller,parallel port ...
only adders ic..gates...multiplexers....!!!!!!

 

[Ajish Babu S]

Re: logic calculator

Hi

Ok.

Then circuit is more complicated. You may use number of ICs for the each Operation.

You can use 74147 decimal to BCD priority encoder and switch or some built in IC for keypad interfacing.

For simple addition and subtraction you may use 7483.

And for display you may use 7- segment, LCD interfacing may difficult without a micro controller

With regards
Ajish Babu S

 

[The Joy of Electronics]

Re: logic calculator

If U want to make it for only two digits then I can say that its hard but not impossible.However making such a sircuit for, say, 8 digits out of chips like 7447 and the like is almost impossible. Even if possible, this project may take months to perform. Now for the former case u need to know that addition and subtraction may be done very easily. Multiplication is a little bit more difficult and the division is the hardest of them all. I invite u to look at my simulations is Orcad. This may help u a little bit.

Regards!