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63 lines
5.5 KiB
HTML
Executable file
63 lines
5.5 KiB
HTML
Executable file
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<meta name="generator" content="ZealOS V0.11">
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<pre style="font-family:monospace;font-size:12pt">
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<a name="l1"></a><span class=cF5> Block Chain</span><span class=cF0>
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<a name="l2"></a>
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<a name="l3"></a>There was a technique on the Commodore 64 where disk blocks were chained together with a block pointer at the end of each
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<a name="l4"></a>block. This is far inferior to having a file allocation table, as in FAT32.
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<a name="l5"></a>
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<a name="l6"></a>The </span><a href="https://zeal-operating-system.github.io/ZealOS/Doc/RedSea.DD.html#l1"><span class=cF4>RedSea</span></a><span class=cF0> file system does not allow files to grow because it only has an allocation bitmap and not a FAT table. This
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<a name="l7"></a>"flaw" is by design. Terry intentionally crippled the operating system, making it a toy with the wisdom that this will
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<a name="l8"></a>prevent commercialization and corruption. The toy spirit of the operating system will be preserved going into the future. Th
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<a name="l9"></a>e vision for this operating system was a modern Commodore 64, which was a fun toy.
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<a name="l10"></a>
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<a name="l11"></a>Doing whole file operations is the ZealOS way of doing thinks. It is the simplest and, ironically, the fastest. It is
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<a name="l12"></a>obnoxious in the characteristic way that ZealOS is obnoxious, flaunting massive modern resources in a way that makes old
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<a name="l13"></a>programmers protest.
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<a name="l14"></a>
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<a name="l15"></a>When doing large, whole-file operations, immediately memory fragmentation is a serious problem, but not so for allocations in
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<a name="l16"></a>the range under a Meg (with occasional larger ones).
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<a name="l17"></a>
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<a name="l18"></a>The file compression scheme in ZealOS only works on whole file operations and the </span><a href="https://zeal-operating-system.github.io/ZealOS/Doc/DolDoc.DD.html#l1"><span class=cF4>DolDoc</span></a><span class=cF0> format cannot have text tacked onto
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<a name="l19"></a>the end, since binary data is at the end.
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<a name="l20"></a>
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<a name="l21"></a>Terry didn't want to spoil fun, so of course offered a way to get awesome performance that is, ironically, superior. </span><span class=cF4>
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<a name="l22"></a></span><a href="https://zeal-operating-system.github.io/ZealOS/Kernel/BlkDev/DiskCFile.CC.html#l151"><span class=cF4>FBlkRead</span></a><span class=cF0>() and </span><a href="https://zeal-operating-system.github.io/ZealOS/Kernel/BlkDev/DiskCFile.CC.html#l214"><span class=cF4>FBlkWrite</span></a><span class=cF0>() allow you to read a block offset from the start of a file. Since files are all contiguous, this is
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<a name="l23"></a>incredibly efficient. You just have to declare the desired file size when you create it with </span><a href="https://zeal-operating-system.github.io/ZealOS/Kernel/BlkDev/DiskCFile.CC.html#l9"><span class=cF4>FOpen</span></a><span class=cF0>() and cannot change it.
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<a name="l24"></a>See </span><a href="https://zeal-operating-system.github.io/ZealOS/Demo/Disk/DataBase.CC.html#l1"><span class=cF4>::/Demo/Disk/DataBase.CC</span></a><span class=cF0>.
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<a name="l25"></a>
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<a name="l26"></a>If you like, you are encouraged to to do raw </span><a href="https://zeal-operating-system.github.io/ZealOS/Kernel/BlkDev/DiskBlk.CC.html#l37"><span class=cF4>BlkRead</span></a><span class=cF0>() and </span><a href="https://zeal-operating-system.github.io/ZealOS/Kernel/BlkDev/DiskBlk.CC.html#l87"><span class=cF4>BlkWrite</span></a><span class=cF0>() directly on a drive. Just get a pointer to a </span><a href="https://zeal-operating-system.github.io/ZealOS/Kernel/KernelA.HH.html#l3381"><span class=cF4>CDrive</span></a><span class=cF0>
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<a name="l27"></a>with </span><a href="https://zeal-operating-system.github.io/ZealOS/Kernel/BlkDev/DiskDrive.CC.html#l211"><span class=cF4>Letter2Drive</span></a><span class=cF0>() and you are on your way! Your computer is supposed to be a fun toy! You can make an entire partition
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<a name="l28"></a>used for a database, or invent a file system.
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<a name="l29"></a>
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<a name="l30"></a>On the whole, the </span><a href="https://zeal-operating-system.github.io/ZealOS/Doc/RedSea.DD.html#l1"><span class=cF4>RedSea</span></a><span class=cF0> file system with its whole-file-only limitation bring beautiful harmony. It beautifully captures
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<a name="l31"></a>the spirit of ZealOS with simplicity and, ironic speed, since contiguous is fastest.
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<a name="l32"></a>
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<a name="l33"></a></span><span class=cF8>
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<a name="l34"></a>* "Commodore 64" is a trademark owned by Polabe Holding NV.
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</span></pre></body>
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