diff --git a/PDP18B/pdp18b_g2tty.c b/PDP18B/pdp18b_g2tty.c index ab35ecea..17b66804 100644 --- a/PDP18B/pdp18b_g2tty.c +++ b/PDP18B/pdp18b_g2tty.c @@ -35,6 +35,46 @@ realized that the axis was perpendicular to the loading dock 4 floors below. A 90-degree turn solved the problem. + GRAPHICS-2 was a command list based graphics display system, + and included a light pen, a "button box" and status bits + for a "dataphone" interface to speak to a GECOS system. + + The UNIX-7 system driver only uses text display, and reserves 269 + words (holding two characters each; the buffer is 273 words, but + three contain display "setup" commands, and the final word in the + buffer must be a display "TRAP" instruction that ends the display + list). + + The UNIX system code triggers a refresh every 10 60Hz "ticks" of + the real time clock. This driver attempts to do detect new text + and send it to a user who has TELNETed in. + + Thoughts on implementing a web interface: + + 538 characters redisplaying at 6Hz (every 10 "ticks") gives a + bandwith requirement of only 26Kbit, and most refreshes won't + change the screen and could be suppressed. So it seems like it + would be reasonable to create a web interface. + + Make a SIMH TCP server port which implements a tiny HTTP server. + The base URL serves up a skeletal page with (lighted) buttons, + and a "display window". + + And either: + + 1) Use "AJAX": an (invisible)