Editing Gerber format (section)

=={{anchor|Standard}}Standard Gerber (revoked)==
Standard Gerber was [[Deprecation#Software deprecation|revoked]] in 2014. It was already obsolete after the introduction of the much more capable Extended Gerber in 1998.<ref name="tavernier"/><ref name="Letter Standard Gerber"/>

Standard Gerber was a [[numerical control]] (NC) format designed by Gerber Systems Corp to drive their vector photo plotters for the PCB industry in the 1960s and 1970s. It was a subset of the [[Electronic Industries Association]] [[RS-274-D]] specification, a format to drive mechanical NC machines in a wide range of industries.<ref>{{cite book |title=EIA Standard RS-274-D Interchangeable Variable Block Data Format for Positioning, Contouring, and Contouroring/Positioning Numerically Controlled Machines |publisher=Electronic Industries Association, Engineering Department, 2001 Eye Street, NW, Washington, D.C. 200006 |date=February 1979}}</ref> It was widely used to drive vector plotters. Standard Gerber was a simple ASCII format consisting of commands and XY coordinates.<ref name="D-codes">{{cite web |url=http://www.artwork.com/gerber/appl2.htm |title=D-codes, Apertures and Gerber Files |date=1991 |author-first=Steve |author-last=DiBartolomeo |publisher=Artwork Conversion Software, Inc. |access-date=2011-10-16}}</ref> An example:
{{sxhl|2=gcode|1=
D11*
X1785250Y2173980D02*
X1796650Y2177730D01*
X1785250Y2181480D01*
X1796650Y2184580D01*
D12*
X3421095Y1407208D03*
X1785250Y2173980D03*
M02*
}}
A Standard Gerber is an NC standard but not an image description standard: essential image information such the coordinate unit and the ''apertures'' definitions are not standardized. (Apertures are the basic shapes, similar to fonts in a PDF file.) They are described in a free-format sidecar text file intended for human reading, called an ''aperture file'' or a ''wheel file''. There are no standards for wheel files. The sender and receiver have to agree on their meaning case-by-case.<ref name="OffWebsite"/><ref name="D-codes"/>

{{anchor|Painting}}Standard Gerber supports only the simple imaging operators that a vector plotter is capable of - drawing tracks and flashing apertures. This is insufficient for efficient PCB fabrication data. Copper pours must be created by ''painting'' (aka ''stroking'' or ''vector-filling'') them with a vast number of tracks.  All but the simplest pads are also painted because of the cost creating a corresponding physical aperture. Painting creates the intended image but results in very large files that take long time to process and need error-prone manual work in CAM.<ref name="PCBFabricationGuide">{{cite web |title=PCB Fabrication Data - A Guide |url=http://www.ucamco.com/downloads |author-first=Karel |author-last=Tavernier |publisher=[[Ucamco]] |access-date=2015-01-08}}</ref><ref name="Painting Considered Harmful"/><ref name="Painting Pads">{{cite web |url=https://www.ucamco.com/files/downloads/file/12/the_scourge_of_cad-to-cam_communication.pdf |title=Painting Pads |author-first=Karel |author-last=Tavernier |work=PCB Design Magazine |issue=November 2013 |date=November 2013 |access-date=2013-11-23}}</ref><ref name="Eurocircuits 10 rules">{{cite web |url=http://www.eurocircuits.com/index.php/technology-guidelines/pcb-layout-data/116-ten-rules-to-provide-perfect-data-for-pcb-production |title=PCB Layout Data |publisher=Eurocircuits |access-date=2011-11-26 |url-status=dead |archive-url=https://web.archive.org/web/20120123162828/http://www.eurocircuits.com/index.php/technology-guidelines/pcb-layout-data/116-ten-rules-to-provide-perfect-data-for-pcb-production |archive-date=2012-01-23 }}</ref>

Standard Gerber was intended for a manual workflow using an NC machine called a vector photoplotter: the plotter operator loads the paper tape with the Standard Gerber file on the plotter, manually sets the coordinate unit on the machine console and mounts the aperture wheel described in the accompanying wheel file. (An aperture wheel is a rotating disk on which physical apertures are mounted, and by rotating the wheel the photoplotter selects the aperture to use.) Standard Gerber is not suitable for automated data transfer between PCB designers and manufacturers.