# VM6502Q and Qrack¶

• Qrack:
• VM6502Q:
• CC65:
• Examples:

## Introduction¶

Qrack is a C++ quantum bit and gate simulator, with the ability to support arbitrary numbers of entangled qubits - up to system limitations. Suitable for embedding in other projects, the Qrack::QInterface contains a full and performant collection of standard quantum gates, as well as variations suitable for register operations and arbitrary rotations.

The developers of Qrack maintain a fork of the ProjectQ quantum computer compiler which can use Qrack as the simulator, generally. This stack is also compatible with the SimulaQron quantum network simulator. Further, we maintain a QrackProvider for Qiskit. Both ProjectQ and Qiskit integrations for Qrack support the PennyLane stack. (For Qiskit, a fork of the Qiskit plugin provides support for a “QrackDevice”.) Qrack’s developers are not directly affiliated with any of these projects, but we thank them for their contribution to the open source quantum computing community!

As a demonstration of the Qrack::QInterface implementation, a MOS-6502 microprocessor [MOS-6502] virtual machine has been modified with a set of new opcodes (MOS-6502Q Opcodes) supporting quantum operations. The vm6502q virtual machine exposes new integrated quantum opcodes such as Hadamard transforms and an X-indexed LDA, with the X register in superposition, across a page of memory. An assembly example of a Grover’s search with a simple oracle function is demonstrated in the examples repository.