From 6cf6cac0a6fd151a073da16a83c00a45ad810abe Mon Sep 17 00:00:00 2001 From: Brittny Hain Date: Wed, 22 Oct 2025 20:28:09 +0000 Subject: [PATCH] Add 'In DOS Memory Management' --- In-DOS-Memory-Management.md | 3 +++ 1 file changed, 3 insertions(+) create mode 100644 In-DOS-Memory-Management.md diff --git a/In-DOS-Memory-Management.md b/In-DOS-Memory-Management.md new file mode 100644 index 0000000..8a4a039 --- /dev/null +++ b/In-DOS-Memory-Management.md @@ -0,0 +1,3 @@ +
In DOS memory administration, prolonged memory refers to memory above the primary megabyte (220 bytes) of tackle area in an IBM Laptop or compatible with an 80286 or later processor. The time period is primarily used below the DOS and Home windows working systems. DOS programs, operating in actual mode or digital x86 mode, can not instantly entry this memory, but are in a position to do so via an utility programming interface (API) called the Prolonged Memory Specification (XMS). This API is applied by a driver (such as HIMEM.SYS) or the working system kernel, which takes care of memory administration and copying memory between typical and [Memory Wave](http://wiki.die-karte-bitte.de/index.php/Benutzer_Diskussion:PoppyEsquivel76) extended memory, by quickly switching the processor into [protected mode](https://www.biggerpockets.com/search?utf8=%E2%9C%93&term=protected%20mode). In this context, the term "extended memory" could check with both the whole of the prolonged memory or solely the portion accessible via this API. Prolonged memory can be accessed immediately by DOS applications operating in protected mode using VCPI or DPMI, two (completely different and incompatible) methods of utilizing protected mode underneath DOS.
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Extended memory should not be confused with expanded memory (EMS), an earlier method for increasing the IBM Laptop's memory capability past 640 kB (655,360 bytes) utilizing an growth card with financial institution switched memory modules. Because of the obtainable support for expanded memory in standard purposes, system drivers had been developed that emulated expanded memory using prolonged memory. Later two additional strategies have been developed permitting direct access to small parts of additional memory above 640 KB from real mode. One of these is referred to because the high memory area (HMA), consisting of the first almost 64 KB of extended memory, and the other is referred to as the upper memory area (UMA \ No newline at end of file