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back2root:ibm-pc-ms-dos:interrupts:int_21:int_21_34 [2023/01/10 15:38] – modification externe 127.0.0.1 | back2root:ibm-pc-ms-dos:interrupts:int_21:int_21_34 [2024/04/08 08:23] (Version actuelle) – ↷ Liens modifiés en raison d'un déplacement. 23.22.35.162 | ||
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* AKA the INDOS flag, this critical section flag may be checked from within an interrupt handler before requesting a DOS service. It is a semaphore that is non-zero when DOS is busy, and zero otherwise. | * AKA the INDOS flag, this critical section flag may be checked from within an interrupt handler before requesting a DOS service. It is a semaphore that is non-zero when DOS is busy, and zero otherwise. | ||
- | * though this flag indicates whether a DOS interrupt is active, it should not be used alone to determine DOS is safe for re-entry; Here's the standard rule for safe DOS entry: if [[back2root: | + | * though this flag indicates whether a DOS interrupt is active, it should not be used alone to determine DOS is safe for re-entry; Here's the standard rule for safe DOS entry: if [[back2root: |
* this interrupt should be used only during TSR initialization; | * this interrupt should be used only during TSR initialization; | ||
* this flag is cleared after a critical error ([[back2root: | * this flag is cleared after a critical error ([[back2root: |