Editing IBM 7090 (section)

==Input/output==
[[Image:IBM 7090 computer.jpg|thumb|left|An IBM 7090 at the NASA [[Ames Research Center]] in 1961, with the director of Ames and several IBM employees. The IBM 7151 Console Control Unit is on the right with two banks of [[IBM 729]] magnetic tape drives in back. The [[IBM 711]] card reader is in front of the man and woman at right.]]
The 7090 series features a data channel architecture for input and output, a forerunner of modern [[direct memory access]] I/O. Up to eight data channels can be attached, with up to ten [[IBM 729]] tape drives attached to each channel. The data channels have their own very limited set of operations called commands.  These are 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 the same modified [[unit record equipment]] introduced with the 704 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 written 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|7094/7044 Direct Coupled System]]'''; the 7044 handled ''[[spooling]]'' between its fast 1400-series peripherals and 1301 or 1302 disk files, and used data channel to data channel communication as the 7094's interface to spooled data, with the 7094 
primarily performing computations. There is also a 7090/7040 DCS.