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Re: ProDOS Kernel Rewritten

> Bryan,  it is not necessary for a disk to be addressed below the block
level,
> which for ProDOS is 512 bytes.  Simply adding another high-order disk
> address byte will get you 256x32MB or 8GB addressable capacity.

    What do you mean 256x32MB?  Is it like 256 sectors?  It may be over
hundred thousand sectors.  It will allow 1024 bytes per sector instead of
512 bytes per sector or higher that will improve performance when it
accesses to read and write faster.

> But there are complications.  Compatibility would certainly not extend to
> utility programs that require knowledge of the file system data structures
> on disk, since they would have to change to accommodate the 3-byte
> disk addresses.  As a result, you would need to write new utilities for
> disk diagnosis, repair, optimization, and file examination.  You may
> find that Macintosh utilities are not the best fit for this purpose.  (But
> it would be nice to have an HFS test/fix/optimize utility for the IIgs.
;-)

    I agree with you that it will need to modify all utilities to support
2GB of ProDOS.

> Of course, all the ProDOS routines that manipulate file system data
> structures would have to be adapted to the new address size and
> 24-bit arithmetic.

    Do not worry that 65816 will not handle 32 bits, but it still can.  16
bits can form into 32 bits using 16-bit arithmetic and 24-bit arithmetic,
but 65C02 still handle 16-bit arithmetic.  I allow 65C02 to support 2GB of
ProDOS while Apple //c + //e to access 2GB of ProDOS.
    It is not important to hold data into memory from 2GB of ProDOS, but
32-bit blocks are still mapped into 24-bit memory.  It might decrease the
performance while loading data into memory from hard drive.

>
> It isn't that it can't be done--it's a question of usefulness.  As others
> have pointed out, a few 32MB ProDOS partitions seem to do the job.
>
> -michael
>
> Check out 8-bit Apple sound that will amaze you on my
> Home page:  http://members.aol.com/MJMahon/