MIX Emulator Library

The backend part of MIX Emulator, a web-based emulator of MIX, the mythical computer invented by Donald Knuth for his book series "The Art of Computer Programming". The library supports assembling and executing programs for MIX, inspecting memory and register contents, working with (virtual) peripheral devices, and traversing execution flow in forward and backward direction. Programs may be executed in either the binary or the decimal mode (which differ in the byte size). Working with devices includes checking correct synchronisation of input/output operations: the emulator fails when the result of an operation is undetermined (e.g., on an attempt to write data to the memory block that is sent to a device without ensuring that the output operation has completed).

The terminal device and floating-point operations are not supported currently.

It is a cross-platform library, written in Scala and transpiled into JavaScript with Scala.js. The JavaScript code is accompanied by .d.ts type definitions.

Usage

1. Subclass BlockAccessFileOps, LineAccessFileInputOps, and LineAccessFileOutputOps and implement the declared input/output operations using the storage you like.

2. Pass instances of the input/output implementation classes to DeviceFrontEnd$.create and get an instance of DeviceFrontEnd.

3. Use one of the methods defined in VirtualMachineFrontEnd$ to create an instance of VirtualMachineFrontEnd.

4. Use the instance of VirtualMachineFrontEnd to execute the program and inspect the virtual machine state.

Reference

If the emulator is useful in your research, consider please referencing the following paper:

Batdalov, R., Ņikiforova, O. Implementation of a MIX Emulator: A Case Study of the Scala Programming Language Facilities. Applied Computer Systems, 2017, 22, pp.47-53. ISSN 2255-8683. e-ISSN 2255-8691. Available from: doi:10.1515/acss-2017-0017