Return to vt.4 CVS log

Up to [Research Unix] / researchv10dc / dist / man / v3 / man4

Annotation of researchv10dc/dist/man/v3/man4/vt.4, revision 1.1

1.1     ! root        1: .pa 1
        !             2: .he 'VT (IV)'2/11/73'VT (IV)'
        !             3: .ti 0
        !             4: NAME           vt -- 11/20 (vt01) interface
        !             5: .sp
        !             6: .ti 0
        !             7: DESCRIPTION
        !             8: .br
        !             9: .in 8
        !            10: The file vt0___ provides
        !            11: the interface to a PDP 11/20 which
        !            12: runs both a VT01A-controlled Tektronix 611
        !            13: storage display,
        !            14: and a Federal Screw Works (Vocal Interface Division)
        !            15: voice synthesizer.
        !            16: The inter-computer interface is
        !            17: a pair of DR-11C word interfaces.
        !            18: 
        !            19: Although the display has essentially only two commands,
        !            20: namely "erase screen" and "display point", the 11/20 program
        !            21: will draw points, lines, and arcs, and print
        !            22: text on the screen.
        !            23: The 11/20 can also type information
        !            24: on the attached 33 TTY and generate utterances via the
        !            25: voice synthesizer.
        !            26: 
        !            27: This special file operates in two basic modes, selected
        !            28: by bit 2 (octal 04) on the 11/20's console switches.
        !            29: If this bit is on at the opening of the file,
        !            30: all bytes written on the file are interpreted as ASCII characters
        !            31: and written on the screen.
        !            32: The screen has 33 lines (1/2 a standard page).
        !            33: The file simulates a 37 TTY: the control characters
        !            34: NL, CR, BS, and TAB are interpreted correctly.
        !            35: It also interprets the usual escape sequences
        !            36: for forward and reverse half-line motion and for
        !            37: full-line reverse.
        !            38: Greek is not available yet.
        !            39: Normally, when the screen is full (i.e. the 34th line is started)
        !            40: the screen is erased before starting a new page.
        !            41: To allow perusal of the displayed text, it is usual to
        !            42: assert bit 0 of the console switches (octal 01).
        !            43: As explained below, this causes the program to
        !            44: pause before erasing until one of the attached pushbuttons
        !            45: is depressed.
        !            46: 
        !            47: If bit 2 of the switches is down, the display is in graphic
        !            48: mode.
        !            49: In this case bytes written on the file
        !            50: are interpreted as display and vocal
        !            51: commands.
        !            52: Each command consists of a single byte usually followed
        !            53: by parameter bytes.
        !            54: Often the parameter bytes represent
        !            55: points in the plotting area.
        !            56: Each point coordinate consists of 2 bytes
        !            57: interpreted as a 2's complement 16-bit number.
        !            58: The plotting area itself measures (+_03777)X(+_03777)
        !            59: (numbers in octal);
        !            60: that is, 12 bits of precision.
        !            61: Attempts to plot
        !            62: points outside the screen limits are ignored.
        !            63: 
        !            64: The graphic and sonic commands are:
        !            65: 
        !            66: .in +5
        !            67: .ti -5
        !            68: order (1); 1 parameter byte
        !            69: .br
        !            70: The parameter indicates a subcommand, possibly followed
        !            71: by subparameter bytes, as follows:
        !            72: .in +5
        !            73: 
        !            74: .ti -5
        !            75: erase (1)
        !            76: .br
        !            77: The screen is erased.
        !            78: This action may be delayed, as explained below,
        !            79: until a pushbutton is depressed.
        !            80: 
        !            81: .ti -5
        !            82: label (2); several subparameter bytes
        !            83: .br
        !            84: The following bytes up to a null character
        !            85: are taken as a label and typed on the console TTY.
        !            86: One of the console switches gives labels
        !            87: a special interpretation, as explained below.
        !            88: 
        !            89: .ti -5
        !            90: .nf
        !            91: display label (3); several subparameter bytes
        !            92: .fi
        !            93: .br
        !            94: The following bytes up to a null byte are printed
        !            95: as ASCII text on the screen.
        !            96: The origin of the text is the last previous point
        !            97: plotted; or the upper left hand of the screen if there were none.
        !            98: 
        !            99: .in -5
        !           100: .ti -5
        !           101: point (2); 4 parameter bytes
        !           102: .br
        !           103: The 4 parameter bytes are taken as a pair of coordinates
        !           104: representing a point to be plotted.
        !           105: 
        !           106: .ti -5
        !           107: line (3); 8 parameter bytes
        !           108: .br
        !           109: The parameter bytes are taken as 2 pairs of coordinates
        !           110: representing the ends of a line segment which is plotted.
        !           111: Only the portion lying within the screen is displayed.
        !           112: 
        !           113: .ti -5
        !           114: frame (4); 1 parameter byte
        !           115: .br
        !           116: The parameter byte is taken as a number of sixtieths of a second;
        !           117: an externally-available lead is asserted for that time.
        !           118: Typically the lead is connected to
        !           119: an automatic camera
        !           120: which advances its film and opens the
        !           121: shutter for the specified time.
        !           122: 
        !           123: .ti -5
        !           124: circle (5); 6 parameter bytes
        !           125: .br
        !           126: The parameter bytes are taken as a coordinate pair representing
        !           127: the origin, and a word representing the radius of a circle.
        !           128: That portion of the circle which lies within the screen is plotted.
        !           129: 
        !           130: .ti -5
        !           131: arc (6); 12 parameter bytes
        !           132: .br
        !           133: The first 4 parameter bytes are taken to be a coordinate-pair
        !           134: representing the center of a circle.
        !           135: The next 4 represent a coordinate-pair specifying a point
        !           136: on this circle.
        !           137: The last 4 should represent another point on the
        !           138: circle.
        !           139: An arc is drawn counter-clockwise from the first circle point
        !           140: to the second.
        !           141: If the two points are the same, the whole circle is drawn.
        !           142: For the second point, only the smaller in magnitude
        !           143: of its two coordinates is significant;
        !           144: the other is used only to find the quadrant of the end of the arc.
        !           145: In any event only points within the screen limits are
        !           146: plotted.
        !           147: 
        !           148: .ti -5
        !           149: dot-line (7); at least 6 parameter bytes
        !           150: .br
        !           151: The first 4 parameter bytes are taken
        !           152: as a coordinate-pair representing the origin
        !           153: of a dot-line.
        !           154: The next byte is taken as a signed
        !           155: x-increment.
        !           156: The next byte is an unsigned word-count,
        !           157: with "0" meaning "256".
        !           158: The indicated
        !           159: number of words is picked up.
        !           160: For each bit in each word a point is plotted
        !           161: which is visible if the bit is "1", invisible
        !           162: if not.
        !           163: High-order bits are plotted first.
        !           164: Each successive point (or non-point) is offset
        !           165: rightward by the given x-increment.
        !           166: 
        !           167: .ti -5
        !           168: speak(8); several parameter bytes
        !           169: .br
        !           170: The following bytes up to a null byte are taken
        !           171: to represent phonemes which are fed to
        !           172: the voice synthesizer.
        !           173: vsp(VII) gives the encoding.
        !           174: 
        !           175: .in -5
        !           176: The 3 low-order console switches of the 11/20
        !           177: modify the operation of the display as follows.
        !           178: 
        !           179: Bit 2 (octal 04) is examined at the time the display
        !           180: file is opened (more precisely, when the first byte
        !           181: is written after an open); as indicated,
        !           182: when on__ it selects character mode, otherwise graphic
        !           183: mode.
        !           184: 
        !           185: Bit 1 (octal 02)
        !           186: determines whether TTY labels are to be interpreted.
        !           187: Unless this bit is on__, labels are ignored.
        !           188: (except to terminate skip mode, see below).
        !           189: 
        !           190: Bit 0 (octal 01) determines
        !           191: whether the display will pause before erasing
        !           192: the screen;
        !           193: if off___ there will be no pause.
        !           194: .a
        !           195: If bit 0 is on__, the erase will occur
        !           196: and displaying will resume only when one of the
        !           197: 16 pushbuttons is depressed.
        !           198: 
        !           199: There is a box with 16 pushbuttons connected
        !           200: to the 11/20.
        !           201: Their state is at all times available in the 11/45
        !           202: by executing the csw___ system call (II).
        !           203: They are used by the 11/20 when it is pausing
        !           204: before an erase.
        !           205: 14 of the buttons merely serve to allow the display
        !           206: to continue.
        !           207: If, however, button 7
        !           208: is pushed,
        !           209: the display will ignore commands up to the
        !           210: next erase command, then ring the TTY console's bell,
        !           211: thereby skipping an entire picture.
        !           212: 
        !           213: If button 8 is depressed,
        !           214: the display will ignore commands up to the next TTY label
        !           215: (whether or not its typing is suppressed) before
        !           216: resuming the displays.
        !           217: Thus a sequence of frames may be skipped.
        !           218: .sp
        !           219: .in 16
        !           220: .ti 0
        !           221: FILES          /dev/vt0
        !           222: .sp
        !           223: .ti 0
        !           224: SEE ALSO       csw(II), vsp(VII)
        !           225: .sp
        !           226: .ti 0
        !           227: BUGS           Two
        !           228: users using vt0 simultaneously
        !           229: can interfere with each other,
        !           230: e.g. plot phonemes or speak display coordinates.

This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.