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This is a benefit when editing keys manually using regedit.exe, the built-in Windows Registry Editor. Because user-based registry settings are loaded from a user-specific path rather than from a read-only system location, the registry allows multiple users to share the same machine, and also allows programs to work for less privileged users.
File access functions in DOS that used the FCB assumed a fixed location for the DTA, initially pointing to a part of the PSP (see next section); this location could be changed by calling a DOS function, with subsequent file accesses implicitly using the new location.
All other references to data use the data segment. The extra segment is the default destination for string operations (for example MOVS or CMPS). FS and GS have no hardware-assigned uses. The instruction format allows an optional segment prefix byte which can be used to override the default segment for selected instructions if desired. [2]
In DOS 1.x, it was necessary for the CS (Code Segment) register to contain the same segment as the PSP at program termination, thus standard programming practice involved saving the DS register (since the DS register is loaded with the PSP segment) along with a zero word to the stack at program start and terminating the program with a RETF instruction, which would pop the saved segment value ...
The set of values pushed for one function call is termed a "stack frame". A stack frame consists at minimum of a return address. Automatic variables are also allocated on the stack. The stack segment traditionally adjoined the heap segment and they grew towards each other; when the stack pointer met the heap pointer, free memory was exhausted.
Segmentation refers to dividing a computer's memory into segments. A reference to a memory location includes a value that identifies a segment and an offset within that segment. A segment descriptor may limit access rights, e.g., read only, only from certain rings.
In computing, protected mode, also called protected virtual address mode, [1] is an operational mode of x86-compatible central processing units (CPUs). It allows system software to use features such as segmentation, virtual memory, paging and safe multi-tasking designed to increase an operating system's control over application software.
TCP window scale option is needed for efficient transfer of data when the bandwidth-delay product (BDP) is greater than 64 KB [1].For instance, if a T1 transmission line of 1.5 Mbit/s was used over a satellite link with a 513 millisecond round-trip time (RTT), the bandwidth-delay product is ,, =, bits or about 96,187 bytes.