1. get_vector and set_vector
- Posted by Noah Smith <nhs6080 at UNIX.TAMU.EDU> Oct 09, 1998
- 445 views
what are get_vector and set_vector doing? they are used as "interrupt handlers" right? i don't see where this fits in with my little programming world. what is an "interrupt" -- i know in asm speak that its' like a system or built-in computer "function" but that would make this redundant, wouldn't it? thx snortboy
2. Re: get_vector and set_vector
- Posted by Ralf Nieuwenhuijsen <nieuwen at XS4ALL.NL> Oct 09, 1998
- 431 views
- Last edited Oct 10, 1998
>what are get_vector and set_vector doing? they are used as "interrupt >handlers" right? i don't see where this fits in with my little >programming world. what is an "interrupt" -- i know in asm speak that >its' like a system or built-in computer "function" but that would make >this redundant, wouldn't it? Well, no actually, it wouldn.t It isnt used to read interrupts, it's used to make an interrupt. For example you can make an interrupt and have a C program running as well, calling it. You can also 'tap' certain informations. For example, whenever a key is pressed, an interrupt occurs. This interrupt could be pointed to *your* code. (read: ASM code you poked into the memory) Etc. Etc. Its just a big table of machine addreses of code that should be executed in certain cases. Dos and you bios both offer a number of interrupts. You might see it like the way DLL's work in windows, but then using an big look-up table, which allows us to overwrite certain functions, or to tap information (your new function could, before it was installed, first store the addres of the old function in a variable, and execute the old function, after the arguments were copied for use within your program. But, this is all pretty low-level stuff.. from the dark doomey days of DOS, where a crash stopped your system. Yet a full stop and a cold reset those days is faster than waiting and seeing Windows fighting the obvious Ralf