LOADALL is the common name for two different, undocumented machine instructions of Intel 80286 and Intel 80386 processors, which allow to access areas normally outside of the IA-32 API scope, like descriptor cache registers. The LOADALL for 286 processors is encoded 0Fh 05h, while the LOADALL for 386 processors is 0Fh 07h. The Intel 80286 is an x86-family 16-bit microprocessor that was introduced by Intel on February 1, 1982. ... An Intel 80386 Microprocessor The Intel 80386 is a microprocessor which was used as the central processing unit (CPU) of many personal computers from 1986 until 1994 and later. ... IA-32, sometimes generically called x86-32, is the computer architecture of Intels most successful microprocessors. ... API redirects here. ...

LOADALL notably allows access to all memory from real mode, without temporarily switching the processor into protected mode.

Programs such as RAMDRIVE (ram disk in MS-DOS), AboveDisk (a commercial package by Above Software which converted hard disk or extended memory into expanded memory), and OS/2 used LOADALL. Examination of the virtual machine monitor code in Windows/386 2.1 shows it uses both the 286 and the much less documented 386 variant. A RAM disk or RAMdrive is a segment of active computer memory, RAM, which is being used as secondary storage, typically a role for a disk drive. ... Microsofts disk operating system, MS-DOS, was Microsofts implementation of DOS, which was the first popular operating system for the IBM PC, and until recently, was widely used on the PC compatible platform. ... Typical hard drives of the mid-1990s. ... Extended memory refers to memory above the first megabyte of address space in an IBM PC with an 80286 or later processor. ... Expanded Memory is memory on an IBM PC compatible computer that is used through the Expanded Memory Specification (EMS) memory paging scheme, enabling access to extra RAM above the 1MB conventional memory area while the processor is in real mode. ... Version 2. ... Microsoft Windows 2. ...

External links

• A rich page on x86.org (http://www.x86.org/articles/loadall/tspec_a3_doc.htm)