CharacteristicsMS-DOS 6.22

ROM DOS 6.22

RAM Space Required (Min.)64KB

18KB

ROM Space Required (Min.)134KB

124KB

Application Size Supported (Max.)637KB

638KB

Disk Size Supported (Min.)32MB

32MB

Floppy Disk Size Supported (Max.)2.88MB

2.88MB

Runs in High Mem AreaYES

YES

EMS, EMM386 SupportYES

YES

XMS, HIMEM SupportYES

YES

SMARTDRV Caching SupportYES

YES

RAM Drive SupportYES

YES

UMB, Load Drivers HighYES

YES

MEMMAKER Memory OptimizationYES

NO

INERLINK / INTERSVR Client / ServerYES

NO

Multi-CONFIG Boot OptionsYES

YES

Power-conserving Device DriversYES

YES

Advanced Power Management (APM) SupportYES

YES

ROM Drive SupportNO

YES

Interactive Start SupportNO

YES

Boots Instantly to ROM ApplicationsNO

YES

Executes from ROMNO

YES

DRVSPACE Support*YES

YES

*Disk Compression Files Add 52-66KB to Memory Requirements

DOS Memory Management: Under MS-DOS, device driver and TSR modules can take up large amounts of conventional memory. A memory manager can move some of these into upper memory blocks or the High Memory Area, freeing up conventional&memory and creating a larger TPA. Memory managers also control access to extended memory, allowing it to be accessed via XMS, or as expanded memory via EMS. Popular DOS memory mangers include EMM386 and QEMM.

Windows Memory Management: Memory management in Microsoft Windows operating systems has evolved into a rich and sophisticated architecture, capable of scaling from the tiny embedded platforms (where Windows executes from ROM) all the way up to the multi-terabyte NUMA configurations, taking full advantage of all capabilities of existing and future hardware designs. With each release of Windows, memory management supports many new features and capabilities. Advances in algorithms and techniques yield a rich and sophisticated code base, which is maintained as a single code base for all platforms and SKUs. Memory management improvements in Windows Vista focused on areas such as dynamic system address space, enhanced NUMA and large system/page support, advanced video model support, I/O and section access, and robustness and diagnosability.