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Libraries:
nonvolatile.library
--background--
DeleteNV
FreeNVData
GetCopyNV
GetNVInfo
GetNVList
SetNVProtection
StoreNV
Include
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The nonvolatile library provides a simple means for an application
developer to manage nonvolatile storage.
OVERVIEW
The nonvolatile library is meant to be used transparently across all
configurations. Currently, nonvolatile storage may consist of NVRAM
and/or disk devices. nonvolatile.library will automatically
access the best nonvolatile storage available in the system. Disk
based storage will be selected first and if not available, NVRAM
storage will be accessed.
* NVRAM
On low-end diskless Amiga platforms, NVRAM may be available. This
RAM will maintain its data contents when the system is powered down.
This is regardless of whether batteries or battery-backed clock are
present. The data stored in NVRAM is accessible only through the
ROM-based nonvolatile library funtion calls. The size of NVRAM
storage is dependant on the system platform and is attainable through
the GetNVInfo() function.
* Disk
In keeping with the general configurability of the Amiga, the actual
disk location used by nonvolatile library when storing to disk may be
changed by the user.
The prefs directory is used on the Amiga for storing many user
configurable options. The location for nonvolatile disk storage
is contained in the file prefs/env-archive/sys/nv_location. This
file should contain a data string that specifies a lockable location.
If the string does not specify a lockable location, the file will
be ignored.
When opened, the nonvolatile library will search all drives within
the system until it finds this file and successfully accomplishes
a Lock on the location specified in the file. To force a rescan of
all drives, the library may be closed and reopened or execute the
GetNVInfo() function.
A simple method for creating a floppy disk for saving nonvolatile
data is the following:
Format a disk with the volume name NV
Create a file prefs/env-archive/sys/nv_location on this disk with
the following contents: NV:nonvolatile
Create a directory nonvolatile
The following is a script file that can be used to make a floppy
for use with nonvolatile library:
.KEY DRIVE/A,DISK
.BRA {
.KET }
format Drive {DRIVE} Name {DISK$NV} noicons ffs
makedir {DRIVE}prefs
makedir {DRIVE}nonvolatile
makedir {DRIVE}prefs/env-archive
makedir {DRIVE}prefs/env-archive/sys
echo {DISK$NV}:nonvolatile >{DRIVE}prefs/env-archive/sys/nv_location
!!!NOTE!!!
Because NVRAM performs disk access, you must open and use its
functionality from a DOS process, not an EXEC task. Normally
your CDGS application is invoked as a DOS process so this
requirement generally should cause you no concern. You just
need to be aware of this requirement should you create an
EXEC task and try to invoke nonvolatile.library from that task.
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