upper memory blocks การใช้

• Later, space between the holes would be used as upper memory blocks ( UMBs ).
• The next stage in the evolution of DOS was for the operating system to use upper memory blocks ( UMBs ) and the high memory area ( HMA ).
• Additionally, on Intel 80386 machines, DR DOS's EMS memory manager allowed the OS to load DOS device drivers into upper memory blocks, further freeing base memory.
• DOS 5 supported the use of the High Memory Area ( HMA ) and Upper Memory Blocks ( UMBs ) on 80286 and later systems to reduce its conventional memory usage.
• These memory areas are referred to as the high memory area ( HMA ) and the upper memory area ( UMA; also referred to as upper memory blocks or UMBs ).
• DR DOS 5.0 was the first DOS to integrate such functionality into the base OS ( loading device drivers into upper memory blocks was possible using third-party software like QEMM ).
• The extended memory manager is also responsible for managing allocations in the high memory area ( HMA ) and the upper memory area ( UMA; also referred to as upper memory blocks or UMBs ).
• This provided a way to copy data to and from extended memory, access to the 65520-byte High Memory Area ( HMA ) directly above the first megabyte of memory and the Upper Memory Block ( UMB ) area.
• As the 640 KB memory restriction became ever more of an obstacle, techniques were found to fill the empty areas with RAM . These areas were referred to as "'upper memory blocks "'( "'UMBs "').
• Notably, they could create ordinary memory in unused parts of the upper memory area ( UMA ) ( the high 384 kB of real mode address space ) called upper memory blocks ( UMBs ) and provided tools for loading small programs, typically TSRs inside ( " LOADHI " or " LOADHIGH " ).