从网上购买的ACR-122U读卡器可以破解并复制一张MIFARE Classic 1K卡片，这种卡片的第0扇区第0块是可以写的。但用
却不能写入可擦写卡片的第0扇区第0块，写其它块是可以的，请问是哪里的限制？如何解除这种限制？
写第0扇区第0块的功能可以用于识别复制卡，一旦识别出第0扇区第0块可写，就说明这张卡是复制卡。这个在门禁上用于排除非法复制卡。
the first data block (block 0) of the first sector (sector 0). It contains the UID and IC manufacturer data. This block is programmed and write protected in the production test.
The first data block (block 0) of the first sector (sector 0) of the clone card,this block is programmable and writable.
never-displayed
