# 8th bit .. bit line number 8. Computer Archetecture

• October 30th 2009, 11:46 AM
partyshoes
8th bit .. bit line number 8. Computer Archetecture
Does anyone know what is meant by the eighth bit line 'counts up to' or 'relates to' 255 in decimal? How do bits hold information, either a 0 or a 1 so powers of 2, but if the eighth line is 2 to the power of 7 then why is it up to but not including 256. (Rofl)(Rofl)(Rofl)(Rofl)(Rofl) (Rofl)(Rofl)(Flower)
• October 30th 2009, 01:35 PM
earboth
Quote:

Originally Posted by partyshoes
Does anyone know what is meant by the eighth bit line 'counts up to' or 'relates to' 255 in decimal? How do bits hold information, either a 0 or a 1 so powers of 2, but if the eighth line is 2 to the power of 7 then why is it up to but not including 256. (Rofl)(Rofl)(Rofl)(Rofl)(Rofl) (Rofl)(Rofl)(Flower)

If all 8 bits are 1 then you get:

$\sum_{n=0}^8\left(2^n\right) = 1+2+4+8+16+32+64+128 = 255$