Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!brl-smoke!gwyn From: gwyn@brl-smoke.ARPA (Doug Gwyn ) Newsgroups: comp.unix.wizards Subject: Re: ATT DMD Info Wanted Message-ID: <6466@brl-smoke.ARPA> Date: Fri, 25-Sep-87 08:20:02 EDT Article-I.D.: brl-smok.6466 Posted: Fri Sep 25 08:20:02 1987 Date-Received: Sat, 26-Sep-87 20:04:48 EDT References: <762@phoenix.PRINCETON.EDU> Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) ) Organization: Ballistic Research Lab (BRL), APG, MD. Lines: 63 In article <762@phoenix.PRINCETON.EDU> lgy@pupthy2.PRINCETON.EDU (Larry Yaffe) writes: >I would greatly appreciate information from knowledgable people about >what these DMD terminals really do, what they cost, the differences >between different models, etc., etc., plus recommendations (ie, names and >phone numbers) of any ATT sales type who might actually know something. The 5620 and 630 are descendants of Rob Pike's "Blit" terminal, which has been written up in TOG, BLTJ, and USENIX conference proceedings. They consist of a bit-map display, keyboard, mouse, CPU, I/O ports, memory, and some built-in firmware. When powered on, they act as simple large-screen (8"x10") CRTs, but the firmware is capable of downloading code that replaces the built-in CRT emulation. The downloaded code has full access to the terminal resources; for example, it might be a mouse-driven video game. The most interesting thing these terminals know how to do using built-in firmware (except on older 5620 models, where a "layersys" application had to be downloaded first) is to enter a multi-window mode of operation known as "layers". In layers mode, each layer consists of a (possibly overlapping) window and associated process in the terminal, initially a CRT emulator process, all processes running "concurrently" (actually using a preemptive task scheduler). A replacement process can be downloaded; commonly available are typsetter emulators, drawing programs, various plot displayers, screen->printer dump drivers, mouse-oriented text editors, strip chart emulators, etc. Layers mode (as well as downloaded applications) require special support software on the host UNIX system. Layers operation resembles other Macintosh-like systems to some degree, although its idea of window manipulation differs. In particular, seldom do DMD applications fold up into "icons"; usually the window simply stays the way it was created. Since overlapping windows are simultaneously active (without loss of display contents under the overlaps), there's not much problem. The most severe constraints of the DMD approach are: - local storage limited to memory (no disk) - remote access conducted via an RS-232 async link (low data traffic bandwidth) - only 6 (5620) or 7 (630) simultaneous windows per host (630 supports additional "detached" local processes) The main advantages of the DMD approach are: + no disk in the office + can be taken home and used effectively over a modem + guaranteed interactive support resources (workstation) Approximate cost (small quantities) is $4000 for a 5620 with 1Mb memory, $2500 for a 630 with 640K memory, $23K for sources for all host software (I think the software prices have been substantially reduced, but in any case note that several terminals can be served by one source license). The basic "layers" support is bundled with SVR3.0 and later as the "windowing utilities" package (no downloadable applications provided); a version for 4.[23]BSD is available from several sources including BRL. The "S" system and some AT&T UNIX System ToolChest software include DMD support. These products originated with AT&T Teletype Corporation, now just AT&T I think, 5555 Touhy Avenue, Skokie, IL 60077. (I think they were scheduled to move to a new address.) I deal with the Government Communications Contract Administrator, Mike Weber at (312)982-2516, but you probably need to deal with someone else. Perhaps Mike knows whom to contact. It's a real shame your AT&T sales reps don't have information about these products, but by now it's no surprise. AT&T has been sending pretty good people to trade shows such as USENIX, so if you can get to one of these you can probably establish suitable contacts. There is also a general information number (800)247-1212 that may be able to help.