A dos-buffer requires (per default) a half KiloByte.
DiskSpeed Reference: 262144 byte, MEMF_FAST, LONG-aligned buffer.
Syncron write-back, or the asyncron delay is started when:
- e.Update-command from FileSystem,
- e.Motor-off-command from FileSystem,
- If a program requests memory, and the cache (the whole RAM)
is filled with data that has to be written back.
- Disk removed : "You must replace Volume"
- If DiskSafe is installed : Before a Reset or a Guru.
- or if the cache is full with data to write (at least 7 free tracks)
The end of the write-access is signalled explicit by the FileSystem
to make sure that a device, software- or hardware-cache in the hardisk has
written the data completely.
Most harddisks have an internal cache of 64 KB.
If only a block (part) of the track is read, the hardware
copies the whole track into a buffer and passes on only the requested
Block.
Future Drive Accelerator makes use of this behavior: It always reads
the whole track into the cache. Reading of a Tracks is a little
bit slower than reading a block.
slow hardware-head, which would be necessary for reading another block.
=> And the hardware isn't stressed because the requested block is
already in the cache.
The used algorithm is required to figure out which tracks is the
last in the queue. This is the oldest track, and if there are several tracks
of the same age, the tracks with the smallest access counter is killed.
If you know a more effective algorithm, don't hesitate and let me know.
The cache is a summary of different tracks.
A medium can be a partition, an inserted diskette/ a removable harddisk / CD or a removed diskette...
or SmartFileSystem_SCSIdirect, ProfiFileSystem-2_SCSIdirect.
FastFileSystem V44.5 is not compatibele with vdisk.device, statram.device, diskspare.device and fms.device
CopyMem(Quick) is used to copy data between cache and system memory.
The hack als works with
FastFilesystem V43.20
The hack removes an alert which informs the user that no OS3.1 is installed.
If you have another Amiga, please read the `readme' text in the update-archive, to find out which file is the best for you.
This document was generated on 14 November 1999 using texi2html 1.55k.