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 (nobody)...and 497 guests Last 5 registered Oplandisks nothingstar N_loop yipe foxtrotromeo Browse members... |
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Hello. I am dumb. Why is the highest decimal number possible with 8 bits 225? How is the 1 subtracted to make it that instead of 256? Thanks |
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Does it start with 0, or soemthing, am I in the right.. thing? |
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The first digit is 2^0, or 1. |
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At least thats what you use when converting from decimal. Me confused. |
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2^7 = 128 2^6 = 64 2^5 = 32 2^4 = 16 2^3 = 8 2^2 = 4 2^1 = 2 2^0 = 1 add them all up = 256 Start right to left Left bit being most significant |
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for example, the 8 bit (base 2) number 11010001 = write it out, left most bit being the most significant thus, 2^7 = 128 (1) 2^6 = 64 (1) 2^5 = 32 (0) 2^4 = 16 (1) 2^3 = 8 (0) 2^2 = 4 (0) 2^1 = 2 (0) 2^0 = 1 (1) add up all the 1bits 128 + 64 + 16 + 1 = 209 |
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256 = 11111111 (base2) if you wanted to subtract 1 (base 10) from that, you would want to take away the 2^0 bit so you would have 255 = 11111110 |
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yeap,thats how id have done it |
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You're talking about multiplication of two four-bit multiplicands whereas you can only represent 0-15 with four bits, which leaves you with 15*15=225 in decimal. But an eight-bit binary can goes as high as 11111111 which is 255, but as 0 count as a number it makes it 256 in decimal value. Although some languages/hardware-interfaces has what's called signed byte variables that reserves one byte for datasigning, which leaves 225 decimals pr. byte. |
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i doubt he needs to learn signed/magnitude right now. best keep it simple |
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Very well :) |
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elusive as much of a genius as you are I would just like to point out that 2^7 = 128 2^6 = 64 2^5 = 32 2^4 = 16 2^3 = 8 2^2 = 4 2^1 = 2 2^0 = 1 = 255 It is completely obvious it couldn't be 256 given the fact that any even number plus an odd number (in this case 1) = an odd number. We'll also leave the exponent and mantissa stuff out for the time being :P |
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Hahaha, brilliant :p |
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These things always leave me knowing less than when I first started reading the thread. |
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lol whoops |
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but you actually were in the right direction by saying that the couting starts with 0. 0-255 is 256 numbers (therefore 256 numbers with the highest being 255) brokephones, yes you are ;p |
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yeah i know, my head is in other places today (work) |
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(anus) |
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hahaha :D |
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Thanks, folks. I think I've got it now. |
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I know. i lose brain cells this way |
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oh my god!! I studied all those things in my school last year! How about the logical doors? nor, xor, and, nand, xnor etc.. ? :) |
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No, beacuse i don't work in networking everyday where everything i do is in 8bit octets (decoding) no ... seriously ... im photocopying this to remind me how fucking stupid i am ... |
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i didnt get any of this shit, but it doesnt mean im dumb, it means that you guys are freaks! |
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