The RFC Archive
 The RFC Archive   RFC 320   « Jump to any RFC number directly 
 RFC Home
Full RFC Index
Recent RFCs
RFC Standards
Best Current Practice
RFC Errata
1 April RFC



IETF RFC 320

Workshop on Hard Copy Line Graphics

Last modified on Thursday, May 22nd, 2008

Permanent link to RFC 320
Search GitHub Wiki for RFC 320
Show other RFCs mentioning RFC 320







Network Working Group                                           R. Reddy
Request for Comments: 320                                            CMU
NIC: 9350                                                  27 March 1972


                  Workshop on Hard Copy Line Graphics

   At CMU we have recently interfaced a Xerox Graphic Printer (ex-LDX)
   to the PDP-10 using a PDP-11 as in intelligent controller for the
   printer.  Specially designed interface and data structures permit the
   PDP-11 to generate each scan line as needed without having to resort
   to the brute force generation of the bit image for the whole page.

   The attached pages were produced using this system with the help of a
   document generation program and a character set design program.  This
   is something personal.

   In response to several requests, we are conducting a one day workshop
   on the XCRIBL system.  The workshop will be held in 3124 Science Hall
   at Carnegie-Mellon University on April 12.  An agenda for the
   workshop is attached.  If you are interested in coming or sending
   someone to this workshop, please contact Dr. D. R. Reddy (412-621-
   6200 ext. 149), Mr. Mack Hicks (412-687-5846) or Miss M. Kostkas
   (412-626-2600 ext. 141), for further information or local
   arrangements.  Local reservations may be made at the Webster Hall
   Hotel (412-621-7700) or the Civic Center Motor Hotel (412-683-6700)
   which are within walking distance of Carnegie-Mellon University.
























Reddy                                                        PAGE 1 top


RFC 320 Workshop on Hard Copy Line Graphics March 1972 CARNEGIE-MELLON UNIVERSITY WORKSHOP ON HARD COPY LINE GRAPHICS April 12 Morning Document Generating Languages and Systems 9:00-9:30 Raj Reddy Overview of the XCRIBL system 9:30-10:20 Joe Newcomer Languages for Document Generation 10:20-10:30 Coffee Break 10:30-12:00 Examples of Document Generation Letter Producing Systems Technical Report Production A Graphics and Gray Scale Image System Afternoon Systems Support 12:00-1:45 Lunch Character Sets (Generation and 1:45-2:45 Lee Erman Modification) 2:45-3:00 Coffee Break 3:00-4:00 George Robertson The PDP-11 Support System 4:00-5:00 Bill Broadly and The PDP-11 XGP Interface (Hardware) Jack Wright Evening Session for the "Hackers" 7:30-10:30 Discussion session of as yet unsolved issues and possible hardware-software solutions. Reddy PAGE 2 top

RFC 320 Workshop on Hard Copy Line Graphics March 1972 XCRIBL SYSTEM COMPUTER SCIENCE DEPARTMENT CARNEGIE-MELLON UNIVERSITY What you are now reading is a computer printout produced by the XCRIBL system. Computers printers do not have typefaces like this one nor can they change typefaces. Conventional computer printers cannot print character sets where the center to center distances are not all the same. The machine that printed this document is a facsimile copying machine built by Xerox a number of years ago. The computer science department of Carnegie-Mellon University has designed and constructed the interface to connect it to a minicomputer (PDP-11) which in turn is linked to a large computer, the PDP-10. The equipment has been working since January. The Xerox Graphic Printer (XGP) works in a similar fashion to the Xerox office copiers. Instead of reflecting light off a printed page as in a copier the XGP uses a cathode ray tube similar to old television tubes as a source of light. The image is drawn as a series of dots on the CRT with a resolution of 12 dots per inch. The line of dots is reflected onto a selenium drum which electrostatically attracts a fine black powder to the exposed selenium areas. The powder is transfered to a moving sheet of paper. Finally a fuser melts the powder onto the paper. To be able to print any character the pattern of dots which will be printed as that character must be entered into the computer along with an indicator of what the pattern represents. To facilitate this a program has been written to design character sets. This program draws a grid on a display terminal. Each box in the grid represents one dot in the final Xerox output. The dots may be set or unset and the character redrawn on the display as frequently as one might desire. Because of the ease with which this may be done it becomes an enjoyable task to design a character set and then be able to change any part of any character. The XGP is also capable of drawing lines and gray scale images. The AI group is using the XGP to print pictures of faces and speech spectrograms. The range of possible uses is boundless. [This RFC was put into machine readable form for entry] [into the online RFC archives by Helene Morin, Via Genie 10/99] Reddy PAGE 3 top

Workshop on Hard Copy Line Graphics RFC TOTAL SIZE: 5600 bytes PUBLICATION DATE: Thursday, May 22nd, 2008 LEGAL RIGHTS: The IETF Trust (see BCP 78)


RFC-ARCHIVE.ORG

© RFC 320: The IETF Trust, Thursday, May 22nd, 2008
© the RFC Archive, 2024, RFC-Archive.org
Maintainer: J. Tunnissen

Privacy Statement