Z80 Multitasking Proof of Concept: Simulating Task Switching for Up to Eight Concurrent Tasks
By
chorlton2080
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Summary
This article describes a proof-of-concept multitasking program for the Z80 processor that can run up to eight separate tasks simultaneously. The program works by saving CPU registers to a task's stack during interrupts, then swapping to the next task's stack pointer. The article notes limitations including task stack size constraints, maximum task count, and performance degradation as more tasks are loaded.
Key quotes
· 4 pulledThis 'Proof of concept' program simulates task multitasking that can run up to eight separate tasks at the same time.
When the CPU triggers an interrupt, CPU registers are saved onto the task's stack, then the next task stack is swapped into the stack pointer.
This code does have limitation in particular the size of the task stacks and the number of tasks.
Also, the more tasks loaded, the slower each task goes.
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