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· Amiga at Work
#2000 Harddrives
5 messages in this thread
So will it live compatibly with a RLL format? Or is the FFS its own private
format?
RLL and FFS are completely separate issues. RLL is the method of
writing data to the disk, and FFS the way the data is sent to the disk.
In other words, RLL is 'how' and FFS is 'what' is being written.
FFS uses all 512 bytes available in a disk sector, while the older
system use only 488 bytes of the 512 for data and the other 24 bytes for
pointers and the like. With the old system, the Amiga had to read in a
sector, extract the 488 bytes from the 512 read and then move that data into
memory. With FFS, the Amiga can read the whole 512 bytes right into memory
with no intermediate steps. (that's a simplistic explanation…but it is
basicaly what happens).
RLL vs MFM is strictly between the controller and the disk…nothing
at all to do with how the Amiga handles the data or not. In fact, RLL and
MFM are used across all PCs, not just the Amiga.
Don
Thanks for explaining. I knew that RLL and MFM were common across
the PC systems, I, however, did not understand how FFS fit in to the system.
Thanks for the explanation. Now I can be a bit more knowledgeable while
shopping for my hard drive.
RLL and FFS are completely separate issues. RLL is the method of
writing data to the disk, and FFS the way the data is sent to the disk.
In other words, RLL is 'how' and FFS is 'what' is being written.
FFS uses all 512 bytes available in a disk sector, while the older
system use only 488 bytes of the 512 for data and the other 24 bytes for
pointers and the like. With the old system, the Amiga had to read in a
sector, extract the 488 bytes from the 512 read and then move that data into
memory. With FFS, the Amiga can read the whole 512 bytes right into memory
with no intermediate steps. (that's a simplistic explanation…but it is
basicaly what happens).
RLL vs MFM is strictly between the controller and the disk…nothing
at all to do with how the Amiga handles the data or not. In fact, RLL and
MFM are used across all PCs, not just the Amiga.
Don