=== Illegal instructions ===
The opcodes in bold are highly unstable.
{| class="wikitable"
| SBX (AXS, SAX) || || CB || || || || || || || || || N || - || - || - || - || - || Z || C || (A ∧ X) - M → X || Subtract Memory from Accumulator "AND" Index Register X
|-
| SHA (AHX, AXA) || || || || || '''9F ''' || || || || || '''93 ''' || - || - || - || - || - || - || - || - || A ∧ X ∧ V → M || Store Accumulator "AND" Index Register X "AND" Value
|-
| SHS (TAS, XAS) || || || || || '''9B ''' || || || || || || - || - || - || - || - || - || - || - || A ∧ X → S, S ∧ (H + 1) → M || Transfer Accumulator "AND" Index Register X to Stack Pointer then Store Stack Pointer "AND" Hi-Byte In Memory
|-
| SHX (SXA, XAS) || || || || || '''9E ''' || || || || || || - || - || - || - || - || - || - || - || X ∧ (H + 1) → M || Store Index Register X "AND" Value
|-
| SHY (SYA, SAY) || || || || '''9C ''' || || || || || || || - || - || - || - || - || - || - || - || Y ∧ (H + 1) → M || Store Index Register Y "AND" Value
|-
| SLO (ASO) || || || 0F || 1F || 1B || 07 || 17 || || 03 || 13 || N || - || - || - || - || - || Z || C || M * 2 → M, A ∨ M → A || Arithmetic Shift Left then "OR" Memory with Accumulator