# Largest number a CPU can work with



## PC person (Feb 2, 2006)

Take for example in this video.

See How Computers Add Numbers In One Lesson - YouTube

The largest number a byte can hold is 255, an adder is composed of certain gates that you output two numbers, but what if this example there were 16 adders instead, the biggest number the CPU can add depends on how many adders it has. What about other operations? Was there a limit on the biggest numbers say an 8088 could work with? I was trying to find it.

Also, for each transistors, each one must have a wire going to both the gate and the source, correct? What piece of hardware/thing lets it specify only the wires to the gates you'd want to turn on?


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## jprince526 (Oct 31, 2013)

You should be able to accomplish this with a ripple-carry adder configuration in which 16 full adders will compute 16 bits. Each consecutive adder inputs the C-out of the previous adder on a 3:2 compression. So if we are assuming that the cpu will process 8 bits with the highest value of 255 for 1 byte, then the sum of a 16 bit binary number will have a maximum value of 65535. This is challengable though depending on several variables, however the script interface carries the exact maximum of 65535 methods. So if it were possible to exceed the maximum based on configuration variables, you would have to also manipulate the script platform.


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