Contribute to ahmadnaserturnkeysolutionsemu8086 development by creating an account on github. This site is not directly affiliated with simulation soft. Ein softwareinterrupt ist ein expliziter aufruf einer unterfunktion meist einer. Most calls to the dos api are invoked using software interrupt 21h int 21h. This interrupt, when given the value of 4ch in ah as is the case here, causes the. Coval systems emu8086 emulator coval computer systems. Page 1 of 19 basic 8086 and dos interrupts that are. Int is an assembly language instruction for x86 processors that generates a software interrupt. Int 21h ah1 read character from standard input, with echo, result is stored in al. Dx, fist byte is buffer size, second byte is number of chars actually read.
The list of all interrupts that are currently supported by the emulator. All trademarks, registered trademarks, product names and company names or logos mentioned herein are the property of their respective owners. Int 21h01h int 21h02h int 21h09h int 21h0ah int 21h4ch. Raw paste data we use cookies for various purposes including analytics. Complete software emulation of intels 8086 microprocessor. Im new to learning assembly language, and im wondering what the command int 21h means. My question is how to do it, the assembler doesnt have any gui, dont know how to compile it and make. A quick reference list of dos interrupts has been extracted from a large list compiled by ralf brown. Int 21h instruction 6 hence in this section we are going to see about int instructions used for keyboard. The dos api is an api which originated with 86dos and is used in msdospc dos and other doscompatible operating systems. Double click on registers or a memory viewer opens an extended viewer. Note that functions 32h, 34h and 50h and above are included, though they are not supported by dos plus. Depending on the context, compiler, or assembler, a software interrupt number is often given as a hexadecimal value.
These functions are commonly referred to as dos int 21h function calls. There are many things emu8086 doesnt do yet, maybe future releases. Ntvdm works by running a dos program in virtual 8086 mode an emulation of real mode within protected. Functions up to and including 57h are documented in this section, all int 21h functions with a higher number applying to later versions of dos than 2.
136 1032 404 623 255 1171 1464 1337 220 837 76 1226 353 545 1471 1516 420 1231 1110 626 591 476 1240 239 317 1459 721 365 654 805 1335 1088 846 893 672 1044 115 1413 1234 119 1079 1197 955 1010 1488