Xerox Graphics Printer - Revision history

Jnc: Similarities between the MIT and CMU interfaces

2024-02-27T10:34:35Z

Similarities between the MIT and CMU interfaces

Jnc: Link 'resolution'

2024-02-27T10:27:43Z

Link 'resolution'

Jnc: /* External links */ + link to original image

2024-02-03T15:35:48Z

‎External links: + link to original image

Jnc: Add image of MIT XGP

2024-02-03T15:32:40Z

Add image of MIT XGP

Larsbrinkhoff: Link to the article about MIT's XGP interface.

2024-01-30T06:17:58Z

Link to the article about MIT's XGP interface.

Larsbrinkhoff: XCRIBL article.

2023-09-14T06:38:57Z

XCRIBL article.

Jnc: /* External links */ +code to run MIT PDP-11 for XGP

2023-09-12T15:56:29Z

‎External links: +code to run MIT PDP-11 for XGP

Larsbrinkhoff: All known XGP sites. Plus PARC, of course.

2023-09-11T08:50:20Z

All known XGP sites. Plus PARC, of course.

Jnc: A decent start

2023-09-11T00:25:14Z

A decent start

New page

The '''Xerox Graphics Printer''' (usually given as the acronym, '''XGP''') was the earliest [[raster]] [[printer]], and thus the ancestor of the ubiquitous [[laser printer]].

It used the xerographic printing process developed by Xerox for copiers: a drum of photovoltaic material holds an [[electrostatic]] charge in darkness, and will conduct away that charge when light is shone on it; that electrostatic charge will hold powdered ink ('toner') on the drum until the ink can be melted onto a piece of paper by heat from the 'fuser'. Thus, a light source can 'draw' images in the static patterns on the drum, which then holds the powdered ink until it is applied to the paper.

The XGP was based on the Xerox LDX (Long Distance Xerography), a facsimile system which came out in 1964, and used a raster scan of the original document. Both the LDX and the XGP used a [[cathode ray tube|CRT]] as the light source. For the XGP, the scanner was dispensed with, and the printer was attached to a computer, which produced the rasters directly. The XGP had a resolution of 192 dots to the inch; it printed on paper unrolled from a large roll of paper, and it had a knife to cut off pages, which could be actuated by the controlling computer.

Xerox provided XGP's to a number of universities by 1972, including MIT, Stanford, and Carnegie-Mellon; each of which produced its own hardware computer interfaces, and software to drive it. MIT and Carnegie-Mellon both used [[PDP-11]]'s to drive their XGP's, but it is not known if there was any design connection between the two.

The one at MIT was connected to the [[Incompatible Timesharing System|ITS]] [[KA10]] MIT-AI via the [[Rubin 10-11 interface]], and it remained the mainstay of printing at [[Technology Square]] until [[Xerox PARC]] donated a [[Dover]] printer (one of the first laser printers) to MIT.

==External links==

* [https://digitalprinting.blogs.xerox.com/2012/08/03/flashback-fridays-looking-back-in-time-at-xerox-history/ Flashback Fridays: Looking Back in Time at Xerox History] - covers the LDX (the image of the printer unit shows it looking much like an XGP)
* [https://eric.ed.gov/?id=ED021591 An Experiment in Library Application of Xerox LDX Facsimile Transmission Equipment] - Appendix I, "LDX Equipment Specifications", gives detail on the LDX 
* [https://digitalprinting.blogs.xerox.com/2017/06/29/marking-40-years-of-xerox-laser-printing-with-its-inventor-gary-starkweather/ Marking 40 Years of Xerox Laser Printing With Its Inventor Gary Starkweather] - mentions his work with the LDX
* [https://www.ietf.org/rfc/rfc320.txt Workshop on Hard Copy Line Graphics] - details of the XGP installation at CMU
* [https://github.com/PDP-10/its/issues/427 XGP - Xerox graphics printer] - includes images of XGP's

[[Category: Printers]]

@@ Line 7: / Line 7: @@
 The XGP was based on the Xerox LDX (Long Distance Xerography), a facsimile system which came out in 1964, and used a raster scan of the original document. Both the LDX and the XGP  used a [[cathode ray tube|CRT]] as the light source. For the XGP, the scanner was dispensed with, and the printer was attached to a computer, which produced the rasters directly. The XGP had a [[resolution]] of 192 dots to the inch; it printed on paper unrolled from a large roll of paper, and it had a knife to cut off pages, which could be actuated by the controlling computer.
-Xerox provided XGP's to a number of universities and research institutes by 1972, including [[Massachusetts Institute of Technology|MIT]], [[Stanford Artificial Intelligence Laboratory|Stanford]], Carnegie-Mellon, [[Information Sciences Institute|ISI]], Caltech, and University of Toronto; each of which produced its own hardware computer interfaces, and software to drive it. MIT and Carnegie-Mellon both used [[PDP-11]]'s to drive their XGP's, but it is not known if there was any design connection between the two.
+Xerox provided XGP's to a number of universities and research institutes by 1972, including [[Massachusetts Institute of Technology|MIT]], [[Stanford Artificial Intelligence Laboratory|Stanford]], Carnegie-Mellon, [[Information Sciences Institute|ISI]], Caltech, and University of Toronto; each of which produced its own hardware computer interfaces, and software to drive it. MIT and Carnegie-Mellon both used [[PDP-11]]'s to drive their XGP's, but it is not known how much there was any design connection between the two (although the similarity of the specifications of the two interfaces make it plausible that there was some knowledge exchange).
 The one at MIT was connected to the [[Incompatible Timesharing System|ITS]] [[KA10]] MIT-AI via the [[Rubin 10-11 interface]], and it remained the mainstay of printing at [[Technology Square]] until [[Xerox PARC]] donated a [[Dover]] printer (one of the first laser printers) to MIT.

@@ Line 5: / Line 5: @@
 It used the xerographic printing process developed by Xerox for copiers: a drum of photovoltaic material holds an [[electrostatic]] charge in darkness, and will conduct away that charge when light is shone on it; that electrostatic charge will hold powdered ink ('toner') on the drum until the ink can be melted onto a piece of paper by heat from the 'fuser'. Thus, a light source can 'draw' images in the static patterns on the drum, which then holds the powdered ink until it is applied to the paper.
-The XGP was based on the Xerox LDX (Long Distance Xerography), a facsimile system which came out in 1964, and used a raster scan of the original document. Both the LDX and the XGP  used a [[cathode ray tube|CRT]] as the light source. For the XGP, the scanner was dispensed with, and the printer was attached to a computer, which produced the rasters directly. The XGP had a resolution of 192 dots to the inch; it printed on paper unrolled from a large roll of paper, and it had a knife to cut off pages, which could be actuated by the controlling computer.
+The XGP was based on the Xerox LDX (Long Distance Xerography), a facsimile system which came out in 1964, and used a raster scan of the original document. Both the LDX and the XGP  used a [[cathode ray tube|CRT]] as the light source. For the XGP, the scanner was dispensed with, and the printer was attached to a computer, which produced the rasters directly. The XGP had a [[resolution]] of 192 dots to the inch; it printed on paper unrolled from a large roll of paper, and it had a knife to cut off pages, which could be actuated by the controlling computer.
 Xerox provided XGP's to a number of universities and research institutes by 1972, including [[Massachusetts Institute of Technology|MIT]], [[Stanford Artificial Intelligence Laboratory|Stanford]], Carnegie-Mellon, [[Information Sciences Institute|ISI]], Caltech, and University of Toronto; each of which produced its own hardware computer interfaces, and software to drive it. MIT and Carnegie-Mellon both used [[PDP-11]]'s to drive their XGP's, but it is not known if there was any design connection between the two.

@@ Line 23: / Line 23: @@
 * [http://shelf2.library.cmu.edu/Tech/backups/227003483.pdf XCRIBL - A Hardcopy Scan Line Graphics System for Document Generation], by R. Reddy, B. Broadley, L. Erman, J. Newcomer, G. Robertson and J. Wright.
 * [https://github.com/PDP-10/its/issues/427 XGP - Xerox graphics printer] - includes images of XGP's
-* [https://github.com/PDP-10/its/blob/master/src/sysen2/xgp.32 XGP >] - code to run MIT PDP-11 for XGP
+* [https://www.computerhistory.org/collections/catalog/102803907 XGP (Xerox Graphics Printer) in MIT AI Lab] - MIT's XGP (center)
 [[Category: Printers]]

← Older revision		Revision as of 15:32, 3 February 2024
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		+	[[Image:MITXGP.jpg\|thumb\|rigt\|300px\|MIT's XGP (at left), along with its controlling PDP-11 (right)]]
		+
	The '''Xerox Graphics Printer''' (usually given as the acronym, '''XGP''') was the earliest [[raster]] [[printer]], and thus the ancestor of the ubiquitous [[laser printer]].		The '''Xerox Graphics Printer''' (usually given as the acronym, '''XGP''') was the earliest [[raster]] [[printer]], and thus the ancestor of the ubiquitous [[laser printer]].

← Older revision		Revision as of 06:17, 30 January 2024
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	The one at MIT was connected to the [[Incompatible Timesharing System\|ITS]] [[KA10]] MIT-AI via the [[Rubin 10-11 interface]], and it remained the mainstay of printing at [[Technology Square]] until [[Xerox PARC]] donated a [[Dover]] printer (one of the first laser printers) to MIT.		The one at MIT was connected to the [[Incompatible Timesharing System\|ITS]] [[KA10]] MIT-AI via the [[Rubin 10-11 interface]], and it remained the mainstay of printing at [[Technology Square]] until [[Xerox PARC]] donated a [[Dover]] printer (one of the first laser printers) to MIT.
		+
		+	==See also==
		+
		+	* [[MIT UNIBUS XGP interface]]

	==External links==		==External links==