Because most disk devices use a sector size of 512 bytes, the first-stage boot loader code must be very small.

由于大多数磁盘设备扇区大小为512字节，因此第一步引导加载程序代码都很小。

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If the disk is bootable, the first sector is called the boot sector, since this is where the boot loader code resides.

如果这个磁盘是可启动的，那么第一个扇区被称为启动扇区，因为这是启动引导代码存在的地方。

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The first 446 bytes are the primary boot loader, which contains both executable code and error message text.

前 446 个字节是主引导加载程序，其中包含可执行代码和错误消息文本。

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