https://twetch.app/t/77426d0efccb5939f059e011cdafe7b8bf66eb…

https://twetch.app/t/77426d0efccb5939f059e011cdafe7b8bf66eb57988faaa223e659ff7e4d8f39 The XCHG operation exchanges the values of HL and DE. Adding HL to itself performs a 16-bit arithmetical left shift with one instruction.