Input/Output
The 7090 series featured a data channel architecture for input and output, a forerunner of modern direct memory access I/O. Up to 8 data channels could be attached, with up to 10 IBM 729 tape drives attached to each channel. The data channels had their own very limited set of operations called commands. These were used with tape (and later, disk) storage as well as card units and printers, and offered high performance for the time. Printing and punched card I/O, however, employed modified unit record equipment and was slow. It became common to use a less expensive IBM 1401 computer to read cards onto magnetic tape for transfer to the 7090/94. Output would be spooled onto tape and transferred to the 1401 for printing or card punching using its much faster peripherals, notably the IBM 1403 line printer. Later IBM introduced the 7094/7044 Direct Coupled System, using data channel to data channel communication, with the 7094 primarily performing computations and the 7044 performing I/O operations.
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Famous quotes containing the words input and/or output:
“Celebrity is a mask that eats into the face. As soon as one is aware of being “somebody,” to be watched and listened to with extra interest, input ceases, and the performer goes blind and deaf in his overanimation. One can either see or be seen.”
—John Updike (b. 1932)
“Lizzie Borden took an axe
And gave her mother forty whacks;
When she saw what she had done,
She gave her father forty-one.”
—Anonymous. Late 19th century ballad.
The quatrain refers to the famous case of Lizzie Borden, tried for the murder of her father and stepmother on Aug. 4, 1892, in Fall River, Massachusetts. Though she was found innocent, there were many who contested the verdict, occasioning a prodigious output of articles and books, including, most recently, Frank Spiering’s Lizzie (1985)