Subject: Re: [stella] AtariVox EEPROM file format|
From: "Eckhard Stolberg" <Eckhard_Stolberg@xxxxxx>
Date: Tue, 30 Nov 2004 22:26:19 +0100
Since only 37 out of 64 possible values are represented in those 6 bits, you
can use the 2 most significant bits to signal the end of a filename or the
beginning of the file extension (assuming ext is always 3 characters).
I think a file-type prefix with a fixed length and position would be better, because it makes it easier for a program to find it's own saved files.
Or if an agreed-upon lookup table for common characters can be created, a flavor of Huffman compression can potentially shrink the filenames even more. Especially since there's elbow room to play with in those 6 bits. The downside, naturally, is more code to de/compress filenames, but someone... perhaps say... Mr. Jentzsch might be able to drum up an uber-tight de/compressor just for this purpose. :)
Paul doesn't really like compressed file names at all, because of the extra ROM and RAM usage that would be required for each game.
And Huffman encoding would mean that file names with uncommon characters would end up being longer. That's not a good thing to have in a file system where all files are a fixed 128 bytes long. If you can't be sure how much space the file name, that the user inputs, is going to take, then you can't really use the extra bytes, that you potentially might save, for your data.