From: utzoo!decvax!ucbvax!info-terms Newsgroups: fa.info-terms Title: Review of Tandberg Data TDV2220 Article-I.D.: ucbvax.181 Posted: Sat Apr 2 06:20:12 1983 Received: Sun Apr 3 02:22:31 1983 >From UCBVAX.@MIT-MC.alpines@G.CC Sat Apr 2 04:54:08 1983 Received: from MIT-MC.ARPA by UCBVAX.ARPA (3.332/3.19) id AA05706; 1 Apr 83 18:10:41 PST (Fri) Received: by UCBVAX.ARPA (3.332/3.19) id AA02566; 2 Apr 83 06:19:04 PST (Sat) To: INFO-TERMS@MIT-MC I've recently acquired a Tandberg Data model TDV2220 display terminal. Here are my comments for anyone interested. Capabilities: The terminal has virtually every editing feature one could ask for, including, but not limited to, add/delete line add/delete character erase fields: to beginning, to end and all erase lines: to beginning, to end and all The add/delete operations are on the slow side -- most everything is done in firmware. The terminal has several forms of protected fields. Display attributes include underline, reverse video, blinking, reduced intensity and various combinations thereof. There are no `magic cookies' left. All control sequences follow the ECMA-48 standards, equivalent to ANSI X3.64. The terminal will operate in either 8-bit (plus parity, if desired) or 7-bit (again, plus optional parity) modes. In 8-bit mode, the 8-bit ECMA sequences are used, although it will accept the 7-bit equivalents. When in 8-bit mode, any editing keys pressed at the terminal will send the 8-bit codes (if the terminal is set in a `duplex' editing mode -- one of several modes available). The terminal has four character sets, the main ASCII/ECMA set, a set of very complete (96) line drawing and histogramming characters, a set of superscript/subscript characters, and a set of characters for displaying control codes as two tiny letters (these are printed only when in a `monitor' mode which prints control codes rather than executing them -- very handy for debugging `termcap' descriptions). Ergonomics: My primary reason for buying the terminal. It has a very large (15 inch diagonal) screen which is backlit. It has green phosphors, so the text is light green, superimposed on a darker green background. Unlike the `reverse video' mode on many terminals, the green background is much lighter and is consistent across the entire screen -- there is no border. I have found the screen to be VERY nice, far better than anything else I have ever used. The letters are formed in a very dense dot matrix on 25 lines. Eye strain is probably as minimal as can be. The monitor sits atop a stand which allows one to adjust the monitor in every direction: tilt, swivel and height. The detached keyboard is expansive and has a very low profile. The home row keys are barely an inch above the tabletop. The keys are interesting: they are not like most `typewriter' style keyboards. The keys have a slightly oval top which is molded onto a square or rectangular matrix of abutting bases. The oval tops are sculpted with a shallow indentation. The keys give resistance which increases up to a point, when they register, then resistance drops until you hit the floor. The touch is very light. It takes a little time to get used to the keyboard, but one becomes addicted to it on short order. What takes getting used to is first the physical design of the keys and second the placement of some common keys: CR, Control, Tab and Escape. The CR key is at the far right and is a vertical key extending for two normal keylengths, but with no horizontal extension at the top. The linefeed is just above it, slightly elongated horizontally. The tab is above the left-hand shift key and is the same size as any alphabetic key. The control is right next to `Q' and again is small. The escape key is to the immediate left of the control key, again small. The backspace key is above the linefeed key on the right. The delete key is on the row of programmable function keys (8 of them, plus shifted versions, making 16), to the far left, at two key rows above the numeric keys. This could be bad news for DEC people. In addition to the function keys, it has a complete set of arrow keys, a numeric keypad and a number of editing keys. You can control DTR from the keyboard. Flexibility: The terminal's operating characteristics are changed in firmware through a set of six full-screen menus. The menus are a wholesale improvement on the VT100 style menus. They contain a full descriptive text of each feature and the options for each feature are mnemonics. One uses the arrow keys to go up and down each menu, pressing shows the options for each feature and the left/right arrow keys select the desired option. Pressing goes back to the full menu. Tabs can be set through the menus, as can the function keys. All the settings are remembered in EAROM. The terminal has two input ports supplied standard, one RS-422, the other RS-232. An additional port is available. It has a printer port with RS-422 standard, RS-232 as an option, with 2k buffer. Various printing modes are available, including transparent printing from the input channels and selective printing of fields from the screen buffer, which may be up to 8 pages in length, contiguous or divided into screenfuls. Disabilities: When using emacs, the fact that the control keys do not repeat (the other keys do) can be annoying. The slowness of the delete/add line/character operations is a small damper on editing. With emacs, I've had problems with lost text from buffer overflows when emacs was busy adding lines and then sending the text afterwards. I'm using James Gosling's emacs, which does not support the XON/XOFF protocol the terminal uses to avoid input buffer overflow. If you are using the editing keys in the mode where they transmit their codes without doing anything, there is no escape to use the keys locally, without changing the terminal mode. It's not a big deal, however, to change the mode. Nonetheless, it spurred me to write a program to `mirror' control codes so that I could scroll up and down through pages of memory. A side effect of this is that one can return the terminal to local mode to use the keys by taking the terminal off-line. The off-line key, however, drops DTR, which will cause some modems to go off line. On the other hand, being able to drop DTR with a stroke of a key is very handy with an auto-dial modem sitting across a room. Using `vi' with this terminal will cause `ripples' on the screen when upscrolling, since `vi' insists on using the `al' capability to upscroll, regardless of whether `sr' is defined. Smooth scroll on the terminal doesn't work properly. Apparently it takes a lot of overhead and the display processor can generate `flashes' on the screen depending on what's being scrolled. I found these flashes annoying enough that I don't use smooth scroll anymore when in multipage mode. For home use, be warned that the terminal has a very heavy inrush current -- the specs say up to 20 amps. Once operating, it takes only 50 watts. On the plus side, however, it is very well shielded and I have had no interference from it at all. It is also well protected against power transients and noise. The terminal checks parity, if you specify a parity bit. A little error LED lights up on the front panel, though the proper character will appear on the screen (not a block as on some terminals which check parity). This can be a bit annoying with Unix, where parity is not something which is handled well or consistently. Also, if one is in 8-bit mode, strange characters appear, since the terminal has a 256-character set. Price: Basic terminal is $1875. 8 pages of memory cost an additional $150. Manual is $40 (very complete). Service manual is $100. Additional input port is $40. RS-232C printer port is $40, 2k print buffer is $10. Miscellaneous: The terminal is also available with a VT100 emulator. For those who purchase this terminal, I have a `termcap' entry for it. Summary: I'm on the whole very happy with the terminal. I bought it for ergonomics and I've been more than satisfied in that category. I was a bit disappointed that the smooth scroll didn't work properly and that the add/delete operations were so slow. It's a very attractive terminal, and for home use that, together with its lack of interference, is very appealing. I really like the set-up menus, too. Harry Weeks Bytel Corporation Berkeley, California (415) 527-1157