Re: ProDOS Plus

["Bryan Parkoff" <nospam@nospam.com>]

>> As for actual file system support, it should have P8 and Smartport 
>> compatibility, original HFS and possibly FAT16.
>>
>> Now the questions arise.
>
> Right.  I think by adding HFS to the list, you've "blown the budget".
> This is no longer a simple extension.  FAT16 may also be in this
> category.  Even increasing the maximum size of a ProDOS(+) volume
> may be well beyond the scope of a "simple extension".

    I try to remember.  Beneath to ProDOS manual states to limit 65,536 
blocks per volume.  I think that ProDOS is designed to read only 8 bit width 
byte.  The free space sector contains 256 bytes as the main sector.  It may 
be interpreted as low byte of block.  One byte is read in the main sector 
and is then read sub-sector.  The sub-sector has second free space sector 
which it contains another 256 bytes.  One byte in the sub-sector is 
interpreted as high byte of block.  You put together high byte and low byte 
into 16 bit width word.  It is how main sector and sub-sector translate to 
block by block.  I can't remember exactly to be correct when you can confirm 
what you read Beneath of ProDOS manual.
    If you wish to enhance ProDOS and be back compatible to ProDOS 8, maybe 
you can change from 8 bit width byte to 16 bit width word.  It allows main 
sector to expand to 16 bit width word and does the sub-sector.  It would 
bring 4,294,967,296 blocks as large volume is to be 2 TeraByte total.

Bryan Parkoff