It was cleanly programmed and relatively bug-free, as well as speed gained from being written completely in x86 assembly language ( this remained the case for all versions until 4. 0 when Lotus switched to C ) and wrote directly to video memory rather than use the slow DOS and / or BIOS text output functions.

This flaw in the Pentium FPU was quickly verified by other people around the Internet, and became known as the Pentium FDIV bug ( FDIV is the x86 assembly language mnemonic for floating-point division ).

* x86 assembly language

1-2-3 was written in x86 assembly language and performed some machine-dependent tricks.

* in x86 assembly implementations such as FASM, they are used to distinguish pointers from their data.

Developers began to target the P5 Pentium processor family almost exclusively with x86 assembly language optimizations which led to the usage of terms such as Pentium compatible processor for software requirements.

* x86 assembly language

Logical addresses can be explicitly specified in x86 assembly language, e. g. ( AT & T syntax ):

About his reverse engineering skills, in a post on his blog he said that in the ' 90s he started with a book (" Programming the 8086 8088 "), the web (" Fravia's site was a goldmine ") and IRC (" Lurked in a x86 assembly IRC channel and picked up tips from wise wizards.

Example: The same Fibonacci number calculator as above, but in x86 assembly language using MASM syntax:

The x86 assembly language covers the many different versions of CPUs that followed, from Intel ; the 80188, 80186, 80286, 80386, 80486, Pentium, Pentium Pro, and so on, as well as non-Intel CPUs from AMD and Cyrix such as the 5x86 and K6 processors, and the NEC V20.

The term x86 applies to any CPU which can run the original assembly language ( usually it will run at least some of the extensions too ).

Each x86 assembly instruction is represented by a mnemonic which, often combined with one or more operands, translates to one or more bytes called an opcode ; the NOP instruction translates to 0x90, for instance and the HLT instruction translates to 0xF4.

x86 assembly language has two main syntax branches: Intel syntax, originally used for documentation of the x86 platform, and AT & T syntax.

In the x86 assembly language, the instruction performs an unconditional jump.

Today, OS-9 is a product name used by both a Motorola 68000-series machine language OS and a portable ( PowerPC, x86, etc.

INT is an assembly language instruction for x86 processors that generates a software interrupt.

* AsmJit — Complete x86 / x64 jit assembler library for C ++ language by Petr Kobalíček

* Xbyak — A x86 / x64 JIT assembler for C ++ language by Herumi

It is mostly written in an object-oriented x86 assembly language dialect and some C / C ++ and is designed to run on top of DOS ( similar to Microsoft Windows ).

The following example uses x86 assembly language to implement a spinlock.

Programmers familiar with x86 assembly language can readily understand the simple implementation above, which works on all CPUs using the x86 architecture.

Due to being written in low-level assembly language for x86 processors, it is not possible to port ZSNES to devices using RISC processors.

Internally, the Athlon is a fully seventh generation x86 processor, the first of its kind.

However, MUL and DIV are special cases, other arithmetic-logical instructions ( ADD, SUB, CMP, AND, OR, XOR, TEST ) may specify any of the eight registers EAX, ECX, EDX, EBX, ESP, EBP, ESI, EDI as the accumulator ( i. e. left operand and destination ); x86 is thus a fairly general register architecture, despite being based on an accumulator model.

It is available on Linux and BSD for Intel x86 ; Linux for Alpha ; Mac OS X for Intel x86 and PowerPC ; and Solaris, IRIX, and HP-UX on their native platforms.

Winelib, a part of the Wine project, is the inverse of Cygwin-it is a free and open source compatibility layer for Unix-like operating systems on the x86 or x86-64 architecture that can allow programs written for Microsoft Windows to run on Unix-like operating systems.

: The best known family of operating systems named " DOS " is that running on IBM PCs type hardware using Intel x86 CPUs or their compatible cousins from other makers.

IA-32 ( Intel Architecture, 32-bit ), also known as x86-32, i386 or x86, is the CISC instruction-set architecture of Intel's most commercially successful microprocessors, and was first implemented in the Intel 80386 as a 32-bit extension of x86 architecture.

An interesting feature of this processor is that it was the first x86 processor with protected mode.

The legacy of the 8086 is enduring in the basic instruction set of today's personal computers and servers ; the 8086 also lent its last two digits to later extended versions of the design, such as the Intel 286 and the Intel 386, all of which eventually became known as the x86 family.

As the original implementation of the 32-bit extension of the 8086 architecture, the 80386 instruction set, programming model, and binary encodings are still the common denominator for all 32-bit x86 processors, this is termed x86, IA-32, or i386-architecture, depending on context.

The modern-day ubiquitous x86 architecture belongs to this category as well, but octal is rarely used on this platform, although certain properties of the binary encoding of opcodes become more readily apparent when displayed in octal, e. g. the ModRM byte, which is divided into fields of 2, 3, and 3 bits, so octal can be useful in describing these encodings.

As this is written, both single and dual x86 CPUs and the StrongARM family are supported.

A simple example ( in the x86 architecture ) is

( A similar scheme is employed to run 68K software on modern x86 Alpha Microsystems machines.

" Rosetta " is the name of a " lightweight dynamic translator " that enables applications compiled for PowerPC processor to run on Apple systems using an x86 processor.

Stanford University's Folding @ home project is a distributed computing research effort which uses its approximately 5 petaFLOPS (~ 10 x86 petaFLOPS ) of computing power to attempt to model the tertiary ( and quaternary ) structures of proteins, as well as other aspects of how and why proteins fold into the inordinately complex and varied shapes they take.

x86 is a series of computer microprocessor instruction set architectures based on the Intel 8086 CPU.

The term is not synonymous with IBM PC compatibility as this implies a multitude of other computer hardware ; embedded systems as well as general-purpose computers used x86 chips before the PC-compatible market started, some of them before the IBM PC itself.

Although most x86 processors used in new personal computers and servers have 64-bit capabilities, to avoid compatibility problems with older computers or systems, the term x86-64 ( or x64 ) is often used to denote 64-bit software, with the term x86 implying only 32-bit.