Re: Toll Booth and junk (was Re(fcc): TI-H: Radio/In...)
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Re: Toll Booth and junk (was Re(fcc): TI-H: Radio/In...)
I might do that, but the larger the HD, the slower it would get. :\ The
AVR is kinda weird.
Doing the math to convert a linear address into a CHS address would take
several hundred us anyway...
Grant
>No no no, use a bit map...that way you don't have to keep checking sector
>after sector, or even fat entry after fat entry to find a free one...one
>sector can hold info for 4096 sectors (1 bit per sector).
>
>-- Jon Olson
>
>-----Original Message-----
>From: David Knaack <dknaack@hotmail.com>
>To: ti-hardware@lists.ticalc.org <ti-hardware@lists.ticalc.org>
>Date: Thursday, November 05, 1998 2:00 PM
>Subject: Re: Toll Booth and junk (was Re(fcc): TI-H: Radio/In...)
>
>
>>
>>>To: ti-hardware@lists.ticalc.org
>>>>Allocation table scanning as I outlined should be
>>>>easy to perform, and would keep down the requirement
>>>>for free space defragmentation. It also allows for
>>>>song deletion without taking a big hit in storage
>>>>space.
>>>
>>>Makes it SSSLLLOOOWWW though since the AVR doesn't have swap space for
>>the
>>>current sector. :)
>>
>>I don't know what you mean. I was refering to the AVR just
>>scanning through the data in the allocation table checking
>>to find a free slot big enough to store a song in.
>>This would consist of a seek, read one byte, check the byte,
>>if it is a 'free slot' byte, seek again, read 8 bytes (two
>>4 byte values), subtract them, then check that length (the
>>amount of free space at that location) against the length
>>of the song to be stored. If the slot is big enough, seek
>>back to the beginning of the slot, write the header, then
>>seek to the data area and start writing the data. No big
>>deal.
>>
>>>>As I mentioned, defragmentation could be as simple
>>>>(and time consuming) as a backup and restore, or
>>>>it could be done periodicly, when fragmented free
>>>>space reaches a certain percentage (which the player
>>>>could calculate at the users request, along with
>>>>largest contigious block and percentage of total
>>>>space used).
>>>
>>>Not possible from the player. It would cost too much if I added
>>external DRAM.
>>
>>What isn't possable, moving data around on the HD?
>>We aren't talking about reading 4MB into memory and
>>writing it back out again, just reading a sector (or
>>some part of it), and writing it back out in a new
>>location, over and over.
>>
>>How much memory does the AVR have without adding
>>external DRAM?
>>
>>DK
>>
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