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- ID:MS Discussion of Memory Status
- Quarterdeck Technical Note
- by Bob Perry
-
- Q.What do the numbers in the Memory Status window mean?
-
- Q.Why does DESQview report 0K for Largest Available Expanded
- Memory?
-
- Q.Why does Total Memory for Expanded not report all my board
- memory?
-
- The Memory Status (MS.COM) program dynamically displays the
- current memory usage of your system at any given moment. It takes
- about 7K "overhead" to run this program. When you run Memory
- Status, the window shows three columns and three rows of numbers.
-
- The ROWS list the three main memory areas of interest:
-
- 1-Common Memory (in Bytes): Common Memory refers to the
- amount of memory in DESQview's Common Memory buffer, and
- generally should not be allowed to drop below 1,000 bytes.
- Allocations are made by running the SETUP program.
-
- 2-Conventional Memory (in Kilobytes, K): Conventional
- Memory refers to the memory available for you to run programs in
- the 0K - 640K memory area of your computer. This consists of any type of
- memory your system uses to fill out to 640K.
-
- 3-Expanded Memory (in Kilobytes, K): Expanded Memory refers
- to memory supplied by expanded memory boards. Memory Status will
- not report expanded memory used for other purposes, such as to
- fill-out conventional memory, RAM disks, print spoolers or disk
- caches.
-
- The COLUMNS in Memory Status are useful in determining the
- current memory sizes of the following three areas:
-
- A-Total Memory: Total Memory refers to the total memory
- available on your system at the moment you started DESQview.
- Such things as device drivers, memory-resident programs and
- buffers (indeed, almost everything you might load in your CONFIG.SYS
- and AUTOEXEC.BAT files before DESQview) will cause the numbers in
- this column to be lower.
-
- B-Total Available: Total Available is the total memory
- available to store data and run programs at the current moment.
- These numbers are TOTAL numbers and do not reflect the size of
- any one program, which is shown in the third column.
-
- C-Largest Available: The third column, and perhaps the most
- useful one, tells you the largest area of contiguous memory
- available at the current moment to run a program. NOTE THAT YOU
- MUST SUBTRACT APPROXIMATELY 14K FROM THESE FIGURES TO ADD OR
- CHANGE A PROGRAM'S MEMORY SIZE. This is because DESQview needs
- about 14K to manage each application.
-
- The Largest Available amount of memory for Expanded Memory,
- which is the lower right corner figure in Memory Status, is
- useful because it determines the size of secondary programs that
- you can multitask (i.e., keep running at the same time as your
- conventional memory program) without swapping. Only expanded
- memory which conforms to EEMS (Enhanced Expanded Memory
- Specification) or EMS 4 (Expanded Memory 4.0 Specfification) will
- result in a number in this location. No other expanded memory
- boards or boards with so-called EMS 4 software drivers can be
- used for multitasking.
-
- Copyright (C) 1990 by Quarterdeck Office Systems
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