A-Level computer science covers a variety of topics, one of which involves some basic low-level programming - the ARM instruction set that needs to be known for exams is a reduced version released by AQA (the examination board) but no interpreter is provided. There are a few other programs that achieve similar effects to this (namely two versions of interpreters from Peter Higginson that can be found here & here and another that is available here). The main issue I've had with these tools is that some (not all) of them have excessive UIs that show information that isn't needed or contextually relevant for the A-Level syllabus and some also don't follow the AQA ARM instruction set accurately (additional instructions are added that would otherwise be unavailable in an exam).
The interpreter itself is very basic and the hardest part of developing this program was designing it so that the modular nature of the codebase would allow simple addition of the AQA Arm instruction set. The instruction set from AQA can be found here, AQArm follows the instruction set to the best of its ability and I am not aware of any deviation from the exam specification - comments, labels, branches, and all of the listed opcodes are supported.
The text area above the code area is a 'command line' (in the loosest sense due to its simplicity) which is used to setup the 'application' memory before running the user-provided code (useful in instances where a question specifies that values are stored in memory locations before execution) using the command SETMEM/XXXX/YYYY XXXX refers to the memory address having a value written to it and YYYY refers to the value being assigned to the memory address.
The right half of the window shows the registers after execution (0 through 12) but it does not currently show carry/comparison data nor the memory space/data belonging to the interpreted process instance.
Question 7.1 in the November 2020 AS paper involves implementing a caesar cipher, all three solutions are able to be run without modification using AQArm.
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