$8$ bit patterns

unsinged integrer

sign integer

$2\text{'}$s compliment

$00000000$

$0$

$+0$

$+0$

$00000001$

$1$

$+1$

$+1$

$00000010$

$2$

$+2$

$+2$

$00001111$

$15$

$+15$

$+15$

$01111101$

$125$

$+125$

$-131$

$011111$

$31$

$+31$

$+31$

$01111111$

$127$

$+127$

$-129$

$100000000$

$128$

$-0$

$-128$

$10000001$

$129$

$-1$

$-127$

$10001111$

$143$

$-143$

$-113$

$1110$

$14$

$-14$

$-14$

$11111111$

$255$

$-255$

$-1$