Memory management

Process definition and design criteria Process and equipment design Company memory (management information) Documentation of risk management decisions Protective systems Normal and upset conditions Chemical and occupational health hazards... 

Process Knowledge and Documentation—The main features here are process definition and design criteria, process and equipment design, company memory (management information), documentation of risk management decisions, protective systems, normal and upset con-dtions, and chemical and occupational health hazards. 

It lends itself to a segregated solution algorithm, thereby offering extremely efficient memory management, since the equations are linearized and sets of equations for each dependent variable are decoupled. 

The 8502 microprocessor used in the 128 mode is ppcode-compatible with the 6502 and 6510, but can now function at two megahertz (MHz), twice the speed of the 6502. All VIC/64 Kernal routines are supported, making program translation much easier. New Kernal routines support special features of the 128, including special routines for memory management. 

A special memory management unit (MMU), located at FF00, is used to control the 128 s complicated memory map. The MMU interprets memory addresses even before the microprocessor sees them. It permits the programmer to swap between 64K banks of memory, but can leave a small portion of memory as common memory. For example, you don t always want zero page and the stack to disappear when you change banks. The MMU permits you to bank between four 64K banks, and allows multiple banks of 256K, up to one megabyte of memory. 

The material that follows actually covers the Memory management subsection of objective 1.1 of the Operating System Technologies exam. For instructional purposes, we feel that it makes more sense to address this topic here. For complete coverage of OS objective 1.1, please also see Part II, Chapters 12 and 14. 

For complete coverage of objective 1.1, please also see Chapter 14. For coverage of the Memory management subobjectives of objective 1.1, refer back to Part I, Chapter 3. 

CONFIG. SYS Loads device drivers and uses the information from the AUTOEXEC. BAT to configure the system environment. Memory management tools and DOS peripheral drivers can be added here. 

EMM386.EXE Reserved memory manager that emulates Expanded Memory in the Extended Memory area (XMS) and provides DOS with the ability to utilize upper memory blocks to load programs and device drivers. 

Extended Memory System (XMS) Memory above 1,024KB that is used by Windows and Windows-based programs. This type of memory cannot be accessed unless the HIMEM.SYS memory manager is loaded in the DOS CONFIG.SYS with a line like DEV1CE=H1MEM.SYS. 

Pentium The Pentium represents the evolution of the 80486 family of microprocessors and adds several notable features, including 8K instruction code and data caches, built-in floating-point processor and memory management unit, as well as a superscalar design and dual pipelining that allow the Pentium to execute more than one instruction per clock cycle. 

RAM disk An area of memory managed by a special device driver and used as a simulated disk. Anything stored on a RAM disk will be erased when the computer is turned off therefore, the contents must be saved onto a real disk. 

C. In a DOS environment, the CONFIG.SYS file is the main configuration file for memory management and device configuration. See Chapter 10 for more information. 

Installing extra off-chip main memory The stacked DRAM and off-chip DRAM have different access delays and thus this approach implies a Non-Uniform Memory Architecture (NIJMA)1231. The operating system has to take charge of the resultant memory management issues. 

Our standard cell benchmarks are from three sources Sun Micro s processor benchmark suite 10, UCLA Dragon benchmark suite 11and MCNC benchmarks 12. These benchmarks have very diverse functionalities and complexities. Sun Micro benchmarks listed in Table 6.1. A are typical CPU circuits such as integer unit, float-point unit, memory management unit, and large register file. They are delivered... 

The microcomputer is the heart of the system. It is a 16-bit microprocessor with added features such as memory management, FP-11 instraetion set, double precision arithmetic, and four-level intenupt bus structure. It and eight other boards eollect and perform all the necessary caleulations for an aeeurate flow measurement. A typieal baekplane eonfiguration depicting computer board plaeement is shown in Figure 2. 

The slave microcomputer consists of a CPU, random access memory, a memory management unit and a master bus interface. It has no ROM (read only memory). The whole slave operating system and the retrieval software are both downloaded from the master. Thus software updates and upgrades are easily implemented even on machines equipped with a large number of slaves. The slave operating system includes the following functions selfcheck, a simple command interpreter and master communication. 

The software environment which was used for developing the search machines was one that CAS had developed starting with the single user DEC RT-11 operating system. Two previous CAS project efforts had built a multitasking and memory management capability on top of RT-11 which was called MERT-11 (Memory Extended RT-11). Application code developed under MERT-11 is written in the DEC Macro-11 Assembler language. 

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