projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 255ab3df KT |
1 | .th "DDSPUT, DDSINIT" III 1/15/73 |
| 2 | .sh NAME | |
| 3 | ddsput \*- put a character on display data set | |
| 4 | .sh SYNOPSIS | |
| 5 | (file descriptor in r0) | |
| 6 | .br | |
| 7 | jsr pc,ddsinit | |
| 8 | .s3 | |
| 9 | (character in r0) | |
| 10 | .br | |
| 11 | jsr pc,ddsput | |
| 12 | .sh DESCRIPTION | |
| 13 | These routines | |
| 14 | used to | |
| 15 | provide an interface to the Display Data Set, a peculiar | |
| 16 | device which can be called by Picturephone sets and which | |
| 17 | will display some of the ASCII character set and certain | |
| 18 | other graphics on the Picturephone screen. | |
| 19 | .s3 | |
| 20 | If the DC11 or other interface hardware is not already | |
| 21 | set up to talk to the Display Data Set, the | |
| 22 | entry should be called with the appropriate file descriptor in r0. | |
| 23 | On the only known DDS attached to UNIX, the associated special file | |
| 24 | is called | |
| 25 | .bd "/dev/ttyc."/p | |
| 26 | .s3 | |
| 27 | .it ddsinit | |
| 28 | also clears the display. | |
| 29 | .se | |
| 30 | Thereafter, characters may be displayed | |
| 31 | by calling | |
| 32 | .it ddsput. | |
| 33 | To the extent possible, | |
| 34 | .it ddsput | |
| 35 | simulates an ordinary terminal. | |
| 36 | Characters falling to the right of the 22x22 screen | |
| 37 | area are ignored; the 23rd line on the screen causes | |
| 38 | the screen to be erased and that line to be put at the top | |
| 39 | of the new display. | |
| 40 | Certain ASCII characters are interpreted specially as follows: | |
| 41 | .s3 | |
| 42 | .lp +6 -6 | |
| 43 | FF clear screen, go to top left | |
| 44 | .lp +6 -6 | |
| 45 | HT expand to right number of spaces | |
| 46 | .lp +5 -5 | |
| 47 | DC1 treat as reverse line feed (move N) | |
| 48 | .lp +5 -5 | |
| 49 | DC2 move cursor 1 place right (move E) | |
| 50 | .lp +5 -5 | |
| 51 | DC3 forward line feed (move S) | |
| 52 | .lp +5 -5 | |
| 53 | DC4 backspace 1 position (move W) | |
| 54 | .lp +5 -5 | |
| 55 | SO enter graph mode | |
| 56 | .lp +5 -5 | |
| 57 | SI leave graph mode | |
| 58 | .lp +5 -5 | |
| 59 | CR put cursor at start of current line | |
| 60 | .i0 | |
| 61 | .s3 | |
| 62 | Graph mode allows display of the non-ASCII characters and | |
| 63 | will be described when hell freezes over. | |
| 64 | .s3 | |
| 65 | Lower-case ASCII alphabetics are mapped into upper case. | |
| 66 | Several ASCII non-alphabetic graphics | |
| 67 | are unavailable as well. Also the lower right circle of | |
| 68 | the "%" character is missing. | |
| 69 | Also one of the circuit cards in the DDS has a crack in it and | |
| 70 | sometimes it doesn't work. | |
| 71 | All in all, | |
| 72 | it is best to avoid this device. | |
| 73 | .sh FILES | |
| 74 | kept in /lib/liba.a | |
| 75 | .sh "SEE ALSO" | |
| 76 | AT&T writeup on DDS | |
| 77 | BUGS yes |