telecom@bu-cs.BU.EDU (TELECOM Moderator) (11/28/88)
I've had a H19/Z19 (the difference being you built it from a Heathkit it is an H19; your terminal was purchased from a computer dealer it is a Z19) for several years. It is an excellent piece of equipment. One enhancement I added about five years ago was the GRAPHICS-PLUS board by Northwest Digital Systems in Seattle, WA. Now although I do not make a great deal of use of the extensive graphics capabilities of this board, there were several other improvements over the standard H19 which induced me to buy and install the unit. Unlike the standard model, where relatively obscure escape sequences are required to make changes in your screen display, I can toggle to page one or page two of a setup screen and do everything by moving the cursor around on the page to the desired value. The escape sequence routines are still there of course, when screen display and cursor type, etc are to be changed by a remote machine. Baud rate, line feed/cr on/off, etc...all can be changed from page one of the setup screen. Page two of the setup screen allows assigning macros of your choice to keys f1 through f5 and blue/red/white. 512 bytes of RAM are available to be used for defining macros, and each key can have up to 128 characters. I use them for logon phrases, etc. Actually there are 16 user definable keys on the H19 running with the Graphics-Plus modification, since f1 to f5, blue, red and white can be shifted or unshifted. Unlike the standard H19 where what scrolls off the top of the screen is lost, the Graphics-Plus board allows for up to 16K of off screen memory. You scroll back and forth through up to seven or eight pages of off screen memory using the f1 to f5 keys in combination with the control and/or control-shift keys. You can make discrete jumps to various pages or slow scrolls as desired. This is a great feature for someone like me who tries to remember what was said in a message which had already scrolled off the screen a few seconds earlier. Like a window shade, you just pull it back down into the screen, read it, and shove it back up out of the way. Example: Control-shift f1 brings back one page of memory. Control-shift f2 shoves it back up again. Control-escape brings up the first of two setup screens. All the standard features of the original H19 are present there in menus. I also have a choice of different screen displays, i.e. the fairly standard 24 x 80; also 24 x 132, 49 x 80 and 49 x 132. There are far too many features in the Graphics-Plus addition to the H19 to describe them all, but the terminal is now very well equipped for graphics work, line drawings, etc if I chose to do that. The board was very easy to install, and took all of fifteen minutes. It fits in the empty slot just in front of the existing board in the H19. Three chips are removed from the original board and installed on the new board. A jumper strap runs from a socket on the old board to the new one. The 150 page manual which comes with it is designed to *supplement* the original documentation from Zenith. It lists dozens of new escape sequences in addition to the twenty or so most common ones which can be accessed from the menus. The Graphics-Plus board preserves the full integrity of your existing H19. No software changes are required to run existing programs. ANSI mode is still available intact if you prefer to use that. In addition, you now get VT52 and VT100 emulation if desired, user definable tab stops, and quite a lot more. I paid about $500 for this board back in 1983, and I am sure the price has come down a lot since then. (I think I paid about the same thing for the Heathkit the year before!) The last address I had for the company (as of 1984) -- Northwest Digital Systems PO Box 15288 Seattle, WA 98115 206-362-6937 I'd say if the Graphics-Plus board is still available from them it would be an excellent buy. It will effectively double or triple the flexibility of your H19 terminal. Patrick Townson