PlasMa - 1. A mini-mainframe simulator machine

A computing system simulator machine designed as a simple homage to the mainframe computers of the 1970's. The full playlist is here https://youtube.com/playlist?list=PLI2uGjCObnyTZ5FLeW3wmIPQseOdsQ1p6 More details, including a Build Guide document and downloads for the PlasMaSim simulator and Plasm assembler, at http://www.philizound.co.uk/plasma/plasma.html A (very) brief summary, including the reasons for building it, can be seen in this live presentation made for the Forth2020 programming group: https://www.youtube.com/watch?v=JT-LL2sf_lY The educational instruction sets shown at 1m12s onwards for Toy-A and Toy-B are variants of the Toy computer used as a teaching aid by Princeton university, USA. Toy-A is based on articles published by Robert Sedgewick and Kevin Wayne; this variant was also built as a hardware unit by Penn Engineering. Toy-B is based on the article “CS 126 Lecture A1: TOY Machine” by Randy Wang. If you studied any of these, your programs should run with little or no change. The advanced instruction set (PleX) described in a later video emulates a more complex computer with additional hardware features 'borrowed' from various real-life machines. It retains the basic architecture from the Toy emulations, but includes a 32-bit accumulator and a much richer set of opcodes such as relative jumps, rotates, multiply and divide, and a dedicated 'no-operation' (NOP) instruction. The first 16 words of memory simulate a non-volatile ‘Fixed Store’ so small programs such as a bootstrap can be retained over a power cycle. The Toy instruction set appears by kind permission of Robert Sedgewick and Kevin Wayne at Princeton university, and is described in their book called Computer Science. More information can be found in the following links: Booksite - https://introcs.cs.princeton.edu/java/home https://introcs.cs.princeton.edu/java/60machine Coursera course - https://www.coursera.org/learn/cs-algorithms-theory-machines