What is PTR in assembly?

The dword ptr means “write a doubleword”. Yes, it stands for pointer, because you put a memory address as destination.

What is the purpose of Emu8086?

Emu8086 combines an advanced source editor, assembler, disassembler, software emulator (Virtual PC) with debugger, and step by step tutorials. This program is extremely helpful for those who just begin to study assembly language. It compiles the source code and executes it on emulator step by step.

What does byte ptr do in assembly?

byte ptr -> it simply means that you want to fetch a byte from the address. if it said word ptr or dword ptr , you would get a word or dword from the address in source index.

What does Qword PTR do?

qword ptr is a hint for the assembler to create a move op-code (machine code) using a 64bit constant address. The value that is provided is a 32bit value (8 hex-digits => 8 times a hex-digit/letter => 8 * 4bits => 32bit).

What does type do in assembly?

The TYPE operator can return the size of a C or C++ type or variable. If the variable is an array, TYPE returns the size of a single element of the array.

What is EMU8086 simulator?

EMU8086 – MICROPROCESSOR EMULATOR is a free emulator for multiple platforms. It provides its user with the ability to emulate old 8086 processors, which were used in Macintosh and Windows computers from the 1980s and early 1990s.

What are addressing modes of 8086?

The addressing modes provided by the 8086 family include displacement-only, base, displacement plus base, base plus indexed, and displacement plus base plus indexed. Variations on these five forms provide the 17 different addressing modes on the 8086.

What are the data transfer instructions in 8086 microprocessor?

8086 Microprocessor Data Transfer Instructions. 1 1. MOV Instruction. The MOV instruction copies a byte or a word from source to destination. Both operands should be of same type either byte or a word. 2 2. 8086 PUSH Instruction. 3 3. 8086 POP Instruction. 4 4. Operand Exchange Instruction (XCHG) 5 5. XLAT Instruction.

What are the different types of 8086 instructions?

The 8086 instruction set contains no-operand, single-operand, and two-operand instructions. Except for string instructions that involve array operations, 8086 instructions do not permit memory-to-memory operations. Appendices F and H provide 8086 instruction reference data and the instruction set (alphabetical order), respectively.

How many op-codes are there in 8086?

The 8086 has approximately 117 different instructions with about 300 op-codes. The 8086 instruction set contains no-operand, single-operand, and two-operand instructions. Except for string instructions that involve array operations, 8086 instructions do not permit memory-to-memory operations.

How do you use PUSH instruction in assembly code?

PUSH Assembly Code The PUSH instruction decrements the SP by 2. You can see in the output the SP=FFFC which decrements by 2 becomes FFFA. The data of AX is pushed to memory location DS: FFFA which is 16FFA in this example.