home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Fresh Fish 8
/
FreshFishVol8-CD1.bin
/
new
/
disk
/
misc
/
vdisk
/
vdisk.doc
< prev
next >
Wrap
Text File
|
1994-12-29
|
13KB
|
284 lines
$VER: vdisk.doc 2.5 (29.12.1994) (C) 1994 by Etienne Vogt
INTRODUCTION
vdisk.device is a driver for a recoverable RAM disk. It started 2 years ago as
a hack of ASDG-RAM (written by Perry S. Kivolowitz). These hacked versions
(1.3 -> 1.12) were not distributed.
As of version 2.0, it has been entirely rewritten, with many new features added :
- Up to 16 units with virtually unlimited size (512 MB)
- Dynamic memory allocation and (optionnaly) deallocation
- Full support of all AmigaDOS Filesystems.
- Will survive the heaviest system crashes as long as its own data is not
corrupted.
- In case of a recovery failure, the cause can be reported by a support command.
VDisk requires AmigaDOS 2.04 or higher (V37). It has been heavily tested on
the following configurations :
- A500 68000 ECS , 1 Mb Chip 2 Mb Fast , WB 2.04 -> 3.1
20 Mb IDE-XT + 170 Mb SCSI HDs
- A3000 68030 ECS, 2 Mb Chip 8 Mb Fast , WB 2.04 -> 3.1
100 Mb + 1 Gb SCSI HDs
- A500 68040(PP&S) ECS , 1 Mb Chip 2 Mb Fast16 8 Mb Fast32 , WB 2.04
50 Mb SCSI HD
- A4000 68040 AGA, 2 Mb Chip 8 Mb Fast , WB 3.0
120 Mb IDE HD
VDisk has been developed independently from StatRam (Another ASDG-RAM based
ram drive written by Richard Waspe and Nicola Salmoria)
DISTRIBUTION
VDisk is Freely Distributable Copyrighted Software (FreeWare).
Some restrictions from the original ASDG-RAM package remains :
This package :
- Must be copied only in the form of the original lha archive, as uploaded
to aminet by the author.
- May not be distributed by any commercial software or hardware vendor.
- May not be sold under any guise.
- Must contain the following copyright information.
vdisk.device, Copyright 1994 by Etienne Vogt.
Inspired from asdg.vdisk.device, Copyright 1987 by Perry S. Kivolowitz
(ASDG Incorporated)
Specifically :
No maker or seller of Amiga expansion hardware or software may distribute
this software in any way. No reseller of public domain software may
distribute this software either (as this in NOT in the public domain).
The only acceptable means of distribution is by networks, bbs's and by
non-profit user groups. Distribution MUST BE FREE (except for media
costs plus a token amount covering only shipping and handling).
Fred Fish is explicitely allowed to include this package in his AmigaLibDisk
collection (either on floppy disk or on CD-ROM), as is the aminet group for
their Aminet CD-ROM.
DISCLAIMER
This software is provided "as is" without any warranty, either expressed or
implied. By using this software, you accept the entire risk as to its quality
and performance.
INSTALLATION
- Copy the file 'vdisk.device' to your DEVS: directory .
NEVER CHANGE THE NAME OF THIS FILE !!!
- Copy the support commands CleanRamDisk, DeleteRamDisk, VDStat to your
C: directory or whatever you like. You may also copy the .info files.
- If you have OS 2.1 or higher, copy the file VD0 to your DEVS:DOSDrivers
directory. You may change the name of this file to whatever you want.
You may edit this file to change some parameters of the recoverable RAM
disk, such as its maximum size. (see below)
- If you have OS 2.0 , join the file VD0.mountlist to your DEVS:MountList
file. You may change the name of the mountlist entry to whatever you want.
You may also edit the mountlist record to change some parameters of the
recoverable RAM disk (see below). Make sure you do not have another
entry with the same name in your mountlist (especially if you use the
old asdg-ram).
Add a 'Mount VD0:' command to your S:User-Startup. If you have 1 Mb or
less memory, it may be wise to put this command at the beginning of your
Startup-Sequence to minimize the risk of recovery failures.
- If you still have OS 1.x, well... It's time to upgrade !
- After that, reboot your Amiga. If all is OK, you should see an icon named
VD-RAM-00 on your Workbench.
NOTE : If you are upgrading from an earlier version of vdisk.device, you
*MUST* issue a 'DeleteRamDisk' command on all active units before
rebooting the system, or unexpected things may happen.
See the support commands below.
CHANGING MOUNTFILE PARAMETERS
WARNING : Changing any other MountFile parameter than those listed below will
cause the vdisk.device to cease to function and to wake up the
GURU with recoverable alert number $50000005 !
After changing ANY parameter of an already active unit, you MUST
issue a 'DeleteRamDisk' command on it before rebooting the system,
or unexpected things may happen.
- DOS device name : Unlike the original asdg.vdisk.device, you can give any
name you want to the recoverable RAM disk. Just change the name of the
mountfile (OS 2.1+) or the mountlist entry (OS 2.0). The default name is
VD0 . It is recommended that the last character be a digit equal to the
unit number.
- Unit : This is the device unit number. You can have several recoverable
RAM disks by having different mountfiles with different values for this
keyword. Valid numbers are 0 to 15, giving a possible total of 16 units.
- Flags : Different options may be selected here. At this time, you have
only one option.
A Flags value of 1 will enable autocleaning on the corresponding unit.
This means that the memory used by the ram disk will automatically decrease
when you delete files in it. This also implies that you cannot use tools
like DiskSalv to recover the deleted files.
A Flags value of 0 disables autocleaning. You must then use the CleanRamDisk
support command to free memory after deleting files. Cleaning may still
happen if the system runs low on memory.
It is recommended that you keep AutoCleaning enabled.
- HighCyl : This is used to specify the maximum size the recoverable RAM disk
is allowed to use. When this size is reached, you will get a 'Volume is full'
requester. Note that unlike RAD, vdisk.device does only allocate memory when
you write files into it.
Do not set this too high ! If you run out of memory before reaching the
maximum size of the RAM disk, you will get a 'write error' requester and
the files in the RAM disk might become corrupt !!!
The recommended maximum size is one fourth of your total FAST RAM.
The HighCyl parameter must be set to an ODD VALUE. HighCyl + 1 is the total
number of 'virtual tracks' usable by the RAM disk. One virtual track has
a size of 8 Kb (16 sectors of 512 bytes).
The default HighCyl value of 63 thus corresponds to a maximum size of
(63 + 1) * 8 = 512 Kb. For a 2 Mb RAM disk, you will set HighCyl to 255.
The maximum allowed value is 65533. This corresponds to 512 Mb.
Remember this value *MUST* be odd !
- Buffers : This is the number of buffers used by the File System to speed up
disk accesses. With a RAM disk, it may actually slow it down, so you'd
better not change this.
- BufMemType : Strictly speaking, this is the type of memory used by the
File System for its internal buffers. For vdisk.device, is also affects
the type of memory allocated to store data you write into it.
Useful values are 1 (any memory), 3 (only CHIP memory, not recommended !)
and 5 (only FAST memory, the default).
If you have both 16 bit and 32 bit FAST memory, and you want to use the
16 bit memory first for the RAM disk, set BufMemType to 517.
- DosType : The type of File System used. Possible values are :
0x444f5300 : Old File System. Slow and not really needed since vdisk.device
has its own checksums.
0x444f5301 : Fast File System. The default.
0x444f5302 : International Old File System. OS 2.1 + only.
0x444f5303 : International Fast File System. OS 2.1 +
0x444f5304 : Directory Caching Old File System. OS 3.0 +
0x444f5305 : Directory Caching Fast File System. OS 3.0 +
International mode may be used if you run OS 2.1 or higher. Directory Caching
is not a good idea since it will slow down the RAM disk.
- Activate : Instructs the mount command to start the device immediately when
set to