Editing Time-sharing (section)

===Batch processing===
{{Main|Batch processing}}
The earliest computers were extremely expensive devices, and very slow. Machines were typically dedicated to a particular set of tasks and operated by control panels, the operator manually entering small programs via switches one at a time. These programs might take hours to run. As computers increased in speed, [[Runtime (program lifecycle phase)|run times]] dropped, and soon the time taken to start up the next program became a concern. Newer [[batch processing]] software and methodologies, including batch operating systems such as [[IBM 7090/94 IBSYS|IBSYS]] (1960), decreased these "dead periods" by queuing up programs ready to run.<ref>{{cite web |url=https://courses.cs.washington.edu/courses/cse451/16wi/readings/lecture_readings/LCM_OperatingSystemsTimeline_Color_acd_newsize.pdf |title=History of Operating Systems}}</ref>

Comparatively inexpensive [[card punch]] or [[paper tape]] writers were used by programmers to write their programs "offline". Programs were submitted to the operations team, which scheduled them to be run. Output (generally printed) was returned to the programmer. The complete process might take days, during which time the programmer might never see the computer. Stanford students made a short film humorously critiquing this situation.<ref>{{Cite web |title=Ellis D. Kropotchev Silent Film - CHM Revolution |url=https://www.computerhistory.org/revolution/punched-cards/2/211/2253 |access-date=2023-05-26 |website=www.computerhistory.org}}</ref>

The alternative of allowing the user to operate the computer directly was generally far too expensive to consider. This was because users might have long periods of entering code while the computer remained idle. This situation limited interactive development to those organizations that could afford to waste computing cycles: large universities for the most part.