Scsi Settings

About settings SCSI ids: A SCSI id is set on a device by configuring jumpers. There are usually three sets of jumpers on a SCSI device. We will see why this is so shortly. You have to know at least the first seven binary numbers. Why binary? Well, why not? Seriously, binary is used because that's the basic way PCs operate - through a series of ones and zeros, ons and offs, true or false, etc... You can see that each example I gave is composed of two choices. In the binary number system, only two symbols are used to represent numbers. Two choices, two numbers. It's a good fit. By the way, "bi" is Latin for "two". The decimal number system, as you know, has 10 symbols(0-9) to represent numbers. "Deci" means "ten". Observe the following: 0 1 2 3 4 5 6 7 8 9 10 When we want to get past nine, we must make the nine a zero and then put a one in the next place over. What happens when we only have two symbols then? 0 1 10 We want to go past one, but there are no more symbols, so we have to make the one a zero, and then put a one in the next place over. OK, now let's count from zero to seven in binary.(remember, SCSI ids begin with zero) 0 1 10 11 100 101 110 111 Notice we never have more than three digits here. Aha! That's why we need the three pairs of jumpers on a SCSI device. A jumper placed on a pair represents a "one", without a jumper and the pair represents a "zero". How then do you represent ids from 0 to 3, which use less than three digits? Remember, any zeros you place to the left don't affect the number. Keeping that in mind, let's see the actual SCSI settings for zero-seven: 000 001 010 011 100 101 110 111