MS-DOS uses INT 21H for its main API functions which provide a low-level is the assembly code to transfer data from one file to other using INT 21H?. INT is an assembly language instruction for x86 processors that generates a software interrupt. For example, INT 21H will generate the software interrupt 0x21 (33 in decimal), causing the function pointed to by the 34th vector in the interrupt. int 21h Dos Interrupt. Int 21h is a common function. The INT 21H instruction in is a software interrupt to vector 21H. It is used for input/output operations.
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assembly language int 21h Dos Interrupt
What does “int 21h” mean in Assembly? – Stack Overflow
Retrieved from ” https: Post as a guest Name. When generating a software interrupt, the processor calls one of the functions pointed to by the interrupt address table, which is located in the first bytes of memory while in real mode See Interrupt vector. The INT 3 instruction is defined for use by debuggers to temporarily replace an instruction in a running program in order to set a breakpoint. From Wikipedia, the free encyclopedia. Sign up using Email and Password. It is therefore entirely possible to use a far-call instruction to start the interrupt-function manually after pushing the flag register.
Thanks in advance for your answer. One of the most useful DOS software interrupts was interrupt 0x I’m new to learning assembly language, and I’m wondering what the command int 21h means.
int 21h Dos Interrupt
By calling it with different parameters in the registers mostly ah and al you could access various IO operations, string output and more. Email Required, but never shown. This page was 88086 edited on 8 Octoberat This is accomplished by entering a bit value corresponding to a kernel function into the EAX register of the processor and then executing INT 0x Other INT instructions are encoded using two bytes.