Dos下Ramdrive.sys实现内存盘的方法
哈哈大侠 记录于 2008年7月25日之前研究虚拟磁盘用法，这招可以在没硬盘时使用(坏掉或检测不到)，
可以在内存上割一块出来模拟成磁碟区，以作临时存放档案之用，
存取速度快，因為是在内存上，但关机后上面的资料就会消失，
所以有重要资料的话要再存回软碟片等等。
要使用虚拟磁盘要在Config.sys驱动RamDisk，一般驱动程序是用Ramdrive.sys，
实际使用经验，使用WinME开机片裡的Ramdrive.sys，
/a必须要先驱动EMS(Expanded Memory Spec.，扩展内存规格)。
可以分割小於32MB的空间出来，最大值就是32767KB。档案1024个。
驱动以后的配置代号目前好像是没有，只能排在所有分割区之后，无法固定-.-。
以下是找到的说明文件：
那个翻译写的很好，简洁有力我喜欢。
==========
RAMDRIVE.SYS [DISKSIZE [SECTORSIZE [ENTRY]]] [/E|/A]
DISKSIZE: 只定虚拟磁盘的大小，范围由4~32768，预设為64，单位為KB
此数值不可超果系统实际所能提供的内存
SECTORSIZE: 只虚拟磁盘的磁区大小由效直為128、256或512欲设為BYTE
如果要设此直同时也要设DISKSIZE三数
ENTRY: 指定根目录容量(包括档名 磁碟标明 子目录)范围為2-1024预设直為64
如要设此直必先设DISKSIZE和SECTORSIZE
/E: 指定以延伸内存(XMS)供虚拟磁盘使用
/A: 指定扩展内存(EMS)供虚拟磁盘使用
如果不设/A或/E会使用传统内存
==========原文：==========
RAMDRIVE.SYS
Uses part of your computer's random-access memory (RAM) to simulate a hard
disk drive. This device driver must be loaded by a or
command in your CONFIG.SYS file.
RAM drives are much faster than hard disk drives because your computer can
read information faster from memory than from a hard disk. A RAM drive
appears to be a normal hard disk drive; you can use it just as you would any
hard disk drive. The most important difference between a real disk drive and
a RAM drive is that because it exists only in memory, information on a RAM
drive is lost when you turn off or restart your computer. You can set up as
many RAM drives as you want, up to the amount of memory your computer has.
To do this, add one RAMDRIVE.SYS line to your CONFIG.SYS file for each
additional RAM drive you want.
Syntax
DEVICE=[drive:][path]RAMDRIVE.SYS [DiskSize [SectorSize [NumEntries]]]
[/E | /A]
Parameters
[drive:][path]
Specifies the location of the RAMDRIVE.SYS file.
DiskSize
Specifies how many kilobytes of memory you want to use for the RAM
drive. For example, to create a 640K RAM drive, specify 640. If you
don't specify an amount, RAMDrive will create a 64K RAM drive. You can
specify a value from 4 to 32767. However, you cannot specify more memory
than your system has available.
SectorSize
Specifies the disk sector size in bytes. The size can be 128, 256, or
512 bytes. (If you include a SectorSize value, you must also include a
value for DiskSize.)
Generally, you should use the default sector size of 512 bytes.
NumEntries
Limits the number of files and directories you can create in the RAM
drive's root directory. The limit can be from 2 to 1024 entries; the
limit you specify is rounded up to the nearest sector size boundary. If
you do not specify a limit, you can create up to 64 entries in the RAM
drive's root directory. (If you include a value for NumEntries, you must
also include values for DiskSize and SectorSize.)
If there is not enough memory to create the RAM drive as specified,
RAMDrive will try to create it with a limit of 16 directory entries.
This may result in a RAM drive with a different limit from the one you
specified.
Switches
/E
Creates the RAM drive in extended memory.
For RAMDrive to use extended memory, your system must be configured so
that it provides extended memory, and a DEVICE command for the
extended-memory manager (such as HIMEM.SYS) must appear in your
CONFIG.SYS file before the DEVICE command for RAMDRIVE.SYS. In general,
it is best to create a RAM drive in extended memory if your system has
extended memory.
/A
Creates the RAM drive in expanded memory.
For RAMDrive to use expanded memory, your system must be configured so
that it provides expanded memory, and the DEVICE command for the
expanded-memory manager (such as EMM386, 386MAX, CEMM, or QEMM) must
appear in your CONFIG.SYS file before DEVICE command for RAMDRIVE.SYS.
举例
dos=high,umb
device=c:\dos\himem.sys
device=c:\dos\emm386.exe NOEMS
devicehigh=c:\dos\ramdrive.sys 2048 /E