Tape Drive Attachment Support
Original Publication Date: 1981-Jul-01
Included in the Prior Art Database: 2005-Feb-11
In the past, a single request for a tape operation had to be expanded into several device commands. A write request, for example, became three device commands, i.e., mode set to insure proper tape density, load I/O to indicate the block size, and write for writing the data. This entire sequence had to be repeated for each block of data written. Additionally the system program had to keep several statistics, such as the number of reads, etc. The present arrangement for the tape drive attachment reduces system program overhead and supports the operations of write, read, read backward, forward space block, backward space block, forward space file, backward space file, erase gap, write tape mark and data security erase.