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diff --git a/doc/rfc/rfc320.txt b/doc/rfc/rfc320.txt new file mode 100644 index 0000000..c6e9fc4 --- /dev/null +++ b/doc/rfc/rfc320.txt @@ -0,0 +1,171 @@ + + + + + + +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] + +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] + +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] + |