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目前,磁带记录方式均采用9道800 RPI(行/时)的 NRZI(不归零制记录)方式和1600RPI 的 PE(相位编码记录)方式。下面介绍的磁带是高记录密度9道6250RPI 的 GCB(成组编码记录)方式。6250 RPI 的 GCR 方式,在7个数据字节上再加一个 ECC(误差校正码)字节,能够校正同时发生的两个磁道误差。另外,数据区中,有再同步脉冲列,具有使“失效”磁道(Dead Track)恢复的功能。IBM 3420-4、6、8型磁带机和日本的相应产品 FACOM 611 A 磁带机均带有6250 RPI装置。1.记录方式NRZI 方式是对应于每一个逻辑“1”的记录信息,磁带上的写入信号反转一次。PE 方
At present, NRZI (Non Return to Zero Recording) method of 800RPI (line / time) and PE (Phase Code Recording) method of 1600RPI are adopted for the tape recording method. The tape described below is a GCB (Group Code Recording) method with 9 recording density of 6250RPI. The 6250 RPI GCR method adds an ECC (Error Correction Code) byte to the seven data bytes to correct for two simultaneous track errors. In addition, there is a resynchronization pulse train in the data area, which has the function of restoring the “Dead Track”. The IBM 3420-4, 6 and 8 tape drives and the corresponding Japanese products FACOM 611 A Tape Drives come with a 6250 RPI unit. 1. Record mode NRZI mode corresponds to each logical “1” record information, the write signal on the tape is reversed. PE side