Editing IBM 1620 (section)

==Peripherals==
[[File:IBM 1627 plotter.mw.jpg|thumb|[[IBM 1627]] drum plotter]]

Available peripherals were:
* [[IBM 1621]]{{snd}} Paper tape reader
* [[IBM 1622]]{{snd}} Punch card reader/punch
* [[IBM 1624]]{{snd}} Paper tape punch (sat inside the 1621 on a shelf)
* [[IBM 1626]]{{snd}} Plotter controller
* [[IBM 1627]]{{snd}} Plotter
* [[IBM 1311]]{{snd}} Disk drive: Model 3 master drive controlling up to 3&ndash;Model 2 slave drives.<ref name=IBM.1311>{{cite web
  |url=http://www-03.ibm.com/ibm/history/exhibits/storage/storage_1311.html
  |archive-url=https://web.archive.org/web/20050121014322/http://www-03.ibm.com/ibm/history/exhibits/storage/storage_1311.html
  |url-status=dead
  |archive-date=January 21, 2005
  |title=IBM 1311|date=23 January 2003}}</ref><ref>"... storage for 2 million characters.</ref>
* [[IBM 1443]]{{snd}} [[Lineprinter|Printer]], flying type bar
* [[IBM 1405]]{{snd}} Disk Drive available as [[Request price quotation|RPQ]] (request price quotation)

The standard "output" mechanism for a program was to punch cards, which was faster than using the typewriter.  These punched cards were then fed through an [[IBM&nbsp;407]] mechanical calculator which could be programmed to print two cards, thus being able to use the additional print columns available on the 407.  All output was synchronous, and the processor paused while the [[Input/Output]] (I/O) device produced the output, so the typewriter output could completely dominate program running time.

A faster output option, the [[IBM 1443]] printer was introduced May 6, 1963,<ref name=IBM.196x>"1963 : On May 6, the IBM 1443 printer, for use with the IBM 1620 data processing system, makes its debut." {{cite web
|url=https://www-03.ibm.com/ibm/history/exhibits/dpd50/dpd50_chronology2.html
|archive-url=https://web.archive.org/web/20100820215557/http://www-03.ibm.com/ibm/history/exhibits/dpd50/dpd50_chronology2.html
|url-status=dead
|archive-date=August 20, 2010
|title=DPD chronology|date=23 January 2003}}</ref> and its 150–600 lines/minute capability was available for use with either model of the 1620.<ref name=x1620.1443>{{cite web  |url=http://bitsavers.trailing-edge.com/pdf/ibm/1620/A26-5730-2_1443_printer_for_1620.pdf |archive-url=https://ghostarchive.org/archive/20221010/http://bitsavers.trailing-edge.com/pdf/ibm/1620/A26-5730-2_1443_printer_for_1620.pdf |archive-date=2022-10-10 |url-status=live
|series=IBM Systems Reference Library |title=IBM 1443 PRINTER for 1620/1710 Systems}}</ref><ref>This publication describes the IBM 1443 Printer as an on-line output unit for the 1620 Data Processing Systems, :Models 1 and. 2, and for the 1710 Control System.  File No. 1620/1710-03. Form A26-5730-2</ref>

It could print either 120 or 144 columns.  The character width was fixed, so it was the paper size that changed; the printer printed 10 characters to the inch, so a printer could print a maximum of 12 inches or 14.4 inches of text.  In addition, the printer had a buffer, so the I/O delay for the processor was reduced.  However, the print instruction would block if the line had not completed.