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- I. INTRODUCTION :
-
- Terminology
-
- Conventional memory -
- It refers to the memory DOS recognizes. This memory is contained in
- the computer system board and the 384K RAM card or Multifunction card
- (if any). The maximum size of the conventional memory is 640 Kbytes
-
- Expanded memory -
- It is a special kind of memory that locates beyond DOS 640K-byte limit.
- Application programs can make use of the expanded memory through the
- Expanded Memory Manager (EMM).
-
- RAM disk -
- A RAM disk is equivalent to an additional disk drive but the storage
- media is some of your computer random access memory (RAM). Unlike
- an floppy disk drive, a RAM disk is all made of electronic parts, so
- it works faster.
-
-
- How to Get Started?
-
- Before you can use the expanded memory in the Expanded Memory
- Specification (EMS) board, you must load the Expaned Memory Manager
- (EMM) driver program. MSDOS supports loading device drivers at boot
- time by creating a CONFIG.SYS file. A CONFIG.SYS file is an ASCII
- code (or text) file which has the following format.
-
- DEVICE=dddddd.SYS para
-
- dddddd.SYS is a device driver program name and para is a parameter
- for the device driver. A CONFIG.SYS file may declare several device
- drivers in the above format each separated by a carriage return.
- When the DOS is booted up, it searches for a CONFIG.SYS file. If a
- CONFIG.SYS file is found, the device drivers declared by the CONFIG.SYS
- are loaded one by one.
- Supplied in this diskette are three device drivers, namely EMM.SYS,
- ERAMDISK.SYS and CRAMDISK.SYS. The function of each device driver
- is explained in Section II.
-
-
- What is the use of a RAM disk?
-
- A RAM disk can speed up a program which has frequent access to a
- disk drive. A RAM disk can be implemented by declaring a RAM disk
- device driver in CONFIG.SYS. Details of implementing a RAM disk are
- described in Section III and IV. After a RAM disk is installed, it
- has no file. You have to copy application programs or data files
- to the RAM disk. This can be done by the COPY command (refer to DOS
- manual for details). After you have finished working with your
- program, any useful data file which has been modified in the RAM disk
- should be copied back to your floppy diskette or hard disk drive,
- since the data in RAM will be destroyed if you turn off the power or
- reboot the system.
-
-
- II. DEVICE DRIVERS INSIDE THE DISKETTE :
-
- EMM.SYS - The expanded memory manager driver program
- This is the driver program for the Expanded Memory Specification
- (EMS) board. It must be installed before the expanded memory in the
- EMS board can be used.
-
- ERAMDISK.SYS - The RAM disk driver program for the EMS board
- This is the driver program for implementing a RAM disk in the EMS
- board. The RAM disk has a drive ID which is the letter next to
- the drive ID letters used by the floppy disk drives and hard disk
- drives in your system. For example, if your system has two floppy
- drives, the drive ID of the RAM disk will be C:. If your system has
- two floppy drives and one hard disk drive, the drive ID of the RAM
- disk will be D: ( A: and B: are drive IDs for the floppy drives,
- and C: is the drive ID for the hard disk drive).
-
- CRAMDISK.SYS - The RAM disk driver program for the conventional
- memory
- This RAM disk driver program is similar to ERAMDISK.SYS but the
- RAM disk occupies conventional memory. The naming of the RAM disk
- drive ID is the same as that in ERAMDISK.SYS. If both ERAMDISK.SYS
- and CRAMDISK.SYS are installed, they will have separate drive IDs
- If this RAM disk is installed, some application programs (e.g.
- SYMPHONY) which requires large conventional memory size cannot be
- run.
-
-
- III. INSTALLING THE DEVICE DRIVER :
-
- To prepare a system diskette with the above device drivers, copy
- the three device drivers program to your system diskette. Then
- create a CONFIG.SYS file in your system diskette to invoke the
- device drivers. The function of the CONFIG.SYS is to load the
- device drivers at boot time. To create a CONFIG.SYS file, you can
- put your system diskette in drive A: and enter the following
- command.
-
- COPY CON: A:CONFIG.SYS <CR>
- DEVICE=EMM.SYS M3 I0 <CR>
- DEVICE=ERAMDISK.SYS 512 <CR>
- DEVICE=CRAMDISK.SYS 128 <CR>
- <F6><CR>
-
- Remark: <CR> is the ENTER key and <F6> is the F6 function key.
- The above CONFIG.SYS file is only an example. The entries
- M3, I0, 512, 128 are parameters for the device drivers.
- They may be varied for different system configurations or
- applications. If a RAM disk for conventional memory is not
- required, the command line DEVICE=CRAMDISK.SYS can be
- ommitted. The command line DEVICE=EMM.SYS must be entered
- before DEVICE=ERAMDISK.SYS.
-
-
- IV. PARAMETERS IN THE DEVICE DRIVERS :
-
- EMM.SYS
- Format : DEVICE=EMM.SYS Ma Ib Ib
-
- M is the parameter heading defining the starting frame address of
- the memory in the EMS board. the 'a' after M represents a number
- which can be 0 to 7.
-
- M parameter Starting frame address (in HEX)
- -----------------------------------------------
- M0 C4000
- M1 C8000
- M2 CC000
- M3 D0000
- M4 D4000
- M5 D8000
- M6 DC000
- M7 E0000
-
- The M parameter can be defined in any of the above values but you
- must make sure that the address space of the EMS memory does not
- conflict with the interface card with ROM memory. The EMS board
- occupies 64K address space starting from the frame address (i.e.
- if M0 is defined, EMS memory occupies address C4000-D3FFF). If
- your system contains a hard disk controller card which has a
- interface ROM with address C8000-CFFFF, parameter M0 or M1 should
- not be used. It is recommended to use parameter M3, since the
- address space does not have conflict with most common interface
- cards.
-
- I is the parameter heading defining the I/O port address of the
- EMS board installed. the 'b' after I represents a number which can
- be 0 to 6.
-
- I parameter I/O port address of DIP switch setting in EMS
- EMS board (in HEX) 1 2 3 4
- ------------------------------------------------------------------
- I0 208 OFF ON ON X
- I1 218 ON OFF ON X
- I2 258 OFF OFF ON X
- I3 268 ON ON OFF X
- I4 2A8 OFF ON OFF X
- I5 2B8 ON OFF OFF X
- I6 2E8 OFF OFF OFF X
-
- Remark : Pole 4 of the DIP switch may be ON or OFF
- If your system is a COMPACT XT with built-in EMS memory,
- the factory set I/O port address is 208 and parameter I0
- should be used.
-
- A computer system can install up to four EMS board. Each EMS
- board must has its own I/O port address. There is a four pole DIP
- (dual in line) switch which can be set to configure different I/O
- port address. The DIP switch setting on each EMS board must be
- different in order to have different I/O port address. You should
- define one I parameter for one EMS board, two I parameters for
- two EMS boards installed in the computer system and so forth.
- For example, if you have four EMS boards in the system, you can
- define the parameters as follows.
-
- DEVICE=EMM.SYS M3 I0 I1 I2 I3
-
-
- ERAMDISK.SYS
- Format : DEVICE=ERAMDISK.SYS nnnn
-
- nnnn represents a number which defines the RAM disk size in Kbyte
- of memory. The minimum number is 16 and the maximum number depends
- on the EMS memory size in your system. Each EMS board contains
- 2048 Kbytes (2 Mbytes) of memory, if the EMS board is fully filled
- with RAM chips. If four EMS boards are installed in your system,
- the EMS memory size is 8192 Kbytes (8 Mbytes).
- (Note: If your system diskette is MSDOS version 2.0 or 2.1 the
- maximum number for RAM disk is 2048. If your system diskette is
- MSDOS version 3.0, 3.1, 3.2 or above the maximum number is 8192.)
-
- CRAMDISK.SYS
- Format : DEVICE=CRAMDISK.SYS nnn
-
- nnn represents a number which defines the RAM disk size in Kbyte
- of memory. The minium number is 16 and the maximum number depends
- on the available conventional memory size. If you application
- program requires large memory size, it is not recommended to
- install this device driver.