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Emulator 8086 :

Konversi Assembler Kode

Ketik kodenya di teks area dan klik [Compile]. Kemudian tentukan tempat penyimpanan filenya. Setelah berhasil, klik [Emulate] untuk meload filenya kedalam emulator.

Direktori File Keluaran:

You can insert these directives in the source code to specify the required output type for the file. Only if compiler cannot find any of these directives it will ask you for output type before creating the file.

Description of Output File Types:

  • #MAKE_COM# - the oldest and the simplest format of an executable file, such files are loaded with 100h prefix (256 bytes). Select Clean from the New menu if you plan to compile a COM file. Compiler directive ORG 100h should be added before the code. Execution always starts from the first byte of the file.
    Supported by DOS and Windows Command Prompt.

  • #MAKE_EXE# - more advanced format of an executable file. Not limited by size and number of segments. Stack segment should be defined in the program. You may select EXE Template from the New menu in to create a simple EXE program with defined Data, Stack, and Code segments.
    Entry point (where execution starts) is defined by a programmer.
    Supported by DOS and Windows Command Prompt.

  • #MAKE_BIN# - a simple executable file. You can define the values of all registers, segment and offset for memory area where this file will be loaded. When loading "MY.BIN" file to emulator it will look for a "MY.BINF" file, and load "MY.BIN" file to location specified in "MY.BINF" file, registers are also set using information in that file (open this file in a text editor to edit or investigate).
    In case emulator is not able to find "MY.BINF" file, current register values are used and "MY.BIN" file is loaded at current CS:IP.
    Execution starts from values in CS:IP.
    This file type is unique to Emu8086 emulator.

    ".BINF file is created automatically by compiler if it finds #MAKE_BIN# directive.
    WARNING! any existing ".binf" file is overwritten!


    Values must be in HEX!

    When not specified these values are set by default:
    LOAD_SEGMENT = 0100
    LOAD_OFFSET = 0000
    CS = ES = SS = DS = 0100
    IP = 0000

    If LOAD_SEGMENT and LOAD_OFFSET are not defined, then CS and IP values are used and vice-versa.

    In case Load to offset value is not zero (0000), ORG ????h should be added to the source of a .BIN file where ????h is the loading offset, this should be done to allow compiler calculate correct addresses.

  • #MAKE_BOOT# - this type is a copy of the first track of a floppy disk (boot sector).
    You can write a boot sector of a virtual floppy (FLOPPY_0) via menu in emulator:
    [Virtual Drive] -> [Write 512 bytes at 7C00 to Boot Sector]
    First you should compile a ".boot" file and load it in emulator (see "micro-os_loader.asm" and "micro-os_kernel.asm" in "Samples" for more info).

    Then select [Virtual Drive] -> [Boot from Floppy] menu to boot emulator from a virtual floppy.

    Then, if you are curious, you may write the virtual floppy to real floppy and boot your computer from it, I recommend using " RawWrite for Windows"
    (note that "micro-os_loader.asm" is not using MS-DOS compatible boot sector, so it's better to use and empty floppy, although it should be IBM (MS-DOS) formatted).
    Compiler directive ORG 7C00h should be added before the code, when computer starts it loads first track of a floppy disk at the address 0000:7C00.
    The size of a .BOOT file should be less then 512 bytes (limited by the size of a disk sector).
    Execution always starts from the first byte of the file.
    This file type is unique to Emu8086 emulator.

Error Processing

Compiler reports about errors in a separate information window:

MOV DS, 100 - is illegal instruction because segment registers cannot be set directly, general purpose register should be used:
MOV AX, 100

MOV AL, 300 - is illegal instruction because AL register has only 8 bits, and thus maximum value for it is 255 (or 11111111b), and the minimum is -128.

Compiler makes several passes before generating the correct machine code, if it finds an error and does not complete the required number of passes it may show incorrect error messages. For example:
ORG 100h

m1: INC AX
LOOP m1                ; not a real error!

MOV AL, 0FFFFh         ; error is here.

List of generated errors:
(7) Condition Jump out of range!: LOOP m1
(9) Wrong parameters: MOV AL, 0FFFFh
(9) Operands do not match: Second operand is over 8 bits!

First error message (7) is incorrect, compiler did not finish calculating the offsets for labels, so it presumes that the offset of m1 label is 0000, that address is out of the range because we start at offset 100h.

Make correction to this line: MOV AL, 0FFFFh (AL cannot hold 0FFFFh value). This fixes both errors! For example:

ORG 100h

m1: INC AX
LOOP m1                ; same code no error!

MOV AL, 0FFh           ; fixed!


ketika menyimpan file kompilasi, kompiler juga menyimpan 2 file yang juga digunakan oleh Emulator untuk menampilkan data ketika dijalankan dan mengkoreksi tiap baris.
  • *.~asm - file ini merupakan source kode asli yang digunakan untuk membuat file exe.

  • *.debug - this file has information that enables the emulator select lines of original source code while running the machine code.

  • *.symbol - Symbol Table, it contains information that enables to show the "Variables" window. It is a text file, so you may view it in any text editor.

  • *.binf - this file contains information that is used by emulator to load BIN file at specified location, and set register values prior execution; (created only if an executable is a BIN file).

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