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A comment on SymbOS: Graphical Z80 Multitasking Operating System. Parent comment

Re:SymbOS: Graphical Z80 Multitasking Operating System by Sir_Cmpwn on Friday January 05, 2018 @08:26PM (#16083262)
For fun, I took a "happy medium" approach in KnightOS. Programs are written with RSTs (basically the z80 version of traps) next to each instruction with a relative address, then the kernel looks up the return address on the stack, partially decodes the next instruction, and then modifies the code in RAM to update the address to the correct one. It's basically just-in-time PIC.

https://github.com/KnightOS/kernel/blob/master/src/00/restar...

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Re:SymbOS: Graphical Z80 Multitasking Operating System by jacquesm on Saturday January 06, 2018 @06:49AM (#16084879)
Heh, that's cool. How do you remember which ones you've modified so you don't do it twice?
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Re:SymbOS: Graphical Z80 Multitasking Operating System by Sir_Cmpwn on Saturday January 06, 2018 @06:01PM (#16087982)
It also modifies the reset (trap instruction) in place and makes it a no-op.
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