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CPU “ram-cpu”

This plugin is the core of the emulation/simulation. Even if we’re supposed to talk about the RAM simulator, because emulation is connected more with imitation of real hardware than the abstract machine, there is a plugin that calls itself a RAM CPU. It is really not accurate, but CPU nowadays means something as the main or core engine of the computation which the machine does. So the name got stuck rather with this convention.

The plugin strictly requires a ram-mem, and three instances of abstract-tape plugins, representing the tapes. After boot, the CPU assigns the specific meaning to each tape.

Status panel

In the following image, you can see the status panel of ram-cpu.

RAM CPU status panel

It is split into three parts. Within the ‘Internal status’ part, there is shown the content of registers R0 (accumulator) and IP. Register IP is the position of the program memory head. It stands for “instruction pointer”. It is pointing at the next instruction being executed.

The input/output part shows the next unread symbol (“next input”), and the last symbol written to the output tape (“last output”). This is just for convenience; it is possible to see the same values in particular tape devices.

The last part, “Run state”, shows in which state the whole emulation is, and it is common to all emulators in emuStudio. The state “breakpoint” means that the emulation is paused.