• • (bullet)
← ← (left-pointing arrow)
→ → (right-pointing arrow)
↕ ↕ (double-headed up/down arrow)
↔ ↔ (double-headed left/right arrow)
① ① (circled '1')
② ② (circled '2')
⋁ ⋁ (or)
⋀ ⋀ (and)
⊕ ⊕ (xor)
(⊻ ('⊻') is now the standard symbol for XOR but Zilog used ⊕)
∼ ∼ (tilde operator)
¬ ¬ (logical not)
≠ ≠ (not equal)
≡ ≡ (identical to)
A picture of the characters in case your browser doesn't display
them correctly: