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Host-to-User Transmission

  • decode: Output from the server-host initially goes through decode, a translation map similar to, and perhaps more complicated than, the encode map. [>nif(urt)>tif(imp ctrl)<tif(net mode)]

  • This map at least formats display output into a simplified logical-entity output stream, of which meaningful pieces may be dealt with in various ways at the user site.

    • The Decode program was sent to the host machine at the same time that the Encode program was sent to the user machine. The program is initially in symbolic form and is compiled for efficient running at the host machine.

    • Lines of charaters should be logically identified so that different line widths can be handled at the user site.

    • Some form of logical line identification must also be made. For example, if a straight line is to be drawn across the display this fact should be transmitted, rather than a series of 500 short vectors.

    • As things firm up, more and more complicated structural display information (in the manner of LEAP) should be sent and accommodated at user sites so that the responsibility for real-time display manipulation may shift closer to the user.

  • imp ctrl: The server-host may also want to send control information to IMPs. Formatting of this information is done by the host decoder. [>tif(urt) <tif(decode)]

  • The other control information supplied by the host decoder is message break up and identification so that proper assembly and sorting can be done at the user site.

From the host decoder, information does to the invisible IMP, and directly to the NET-to-user translator. The only operation done on the messages is that they may be shuffled.

  • urt: The user reception translator accepts messages from the user-site IMP 1 and fixes them up for user-site display. [>nif(d ctrl)>tif(prgm ctrl)<tif(imp ctrl)<nif(decode)]

  • The minimal action is a reordering of the message pieces.

  • dctrl: For display output, however, more needs to be done. The NET logical display information must be put in the format of the user site. Display control does this job. Since it coordinates between (encode) and (decode) it is able to offer features of display management local to the user site. [>nif(display)<nif(urt)]

  • prgmctrl: Another action may be the selective translation and routing of information to particular user-site subsystems. [>tif(dctrl)<tif(urt)]

    • For example, blocks of floating-point information may be converted to user-style words and sent, in block form, to a subsystem for processing or storage.

    • The styles and translation of this information may well be a compact binary format suitable for quick translation, rather than a print-image-oriented format.

  • (display): is the output to the user. [<nif(d ctrl)]

User-to-Host Indirect Transmission​

  • (net mode): This is the mode where a remote user can link to a node indirectly through another node. [<nif(decode)<tif(hrt)]