The ASCII Video Terminal is based on a low cost 32-bit microcontroller from Microchip. Power requirement is 5V at 50mA plus any current drawn from the 3.3V pin on the serial connector.Three built in fonts (standard, large and jumbo) and four character attributes (normal, underline, reverse and invisible).

Graphics resolution is 480x288 pixels in VGA 25 line mode, 480x432 pixels in VGA 36 line mode, 288x216 in PAL composite and 264x180 pixels in NTSC composite mode.Extensions include graphics codes for drawing lines, boxes and circles (which can be hollow or filled) This can be used as a USB to serial converter Baud rates from 40 to 1,000,000 bits per second with odd, even or no parity and one or two stop bits Standard PS2 compatible keyboard input with support for standard US keyboard layout or French, German, Italian, Belgian, Russian or United Kingdom keyboard layouts.Composite video can display 18 lines x 48 characters (PAL) or 15 lines x 44 characters (NTSC).VGA can display 24 lines x 80 characters or an extended resolution of 36 lines x 80 characters.

VGA or Composite Video output with automatic switch over.

Single chip ASCII video display terminal with VT100 and VT52 emulation.

Back issues of the article can be purchased from Silicon Chip or electronic access can be purchased for about the cost of the printed issue. This web page provides all that you need to build the project but for a fuller description you should refer to the original magazine article. The ASCII Video Terminal project was described in the July 2014 issue of Silicon Chip magazine. You can use it to build a complete terminal (as illustrated on the left) or as a single chip video driver, keyboard interface or whatever. The entire terminal (video generator, serial interface, etc) is contained in a single low cost chip.

The firmware emulates most features of the DEC VT100 and VT52 terminals and has extensions for graphics (lines, boxes and circles) as well as alternative fonts (large and jumbo). There is also a USB interface which supports serial over USB and acts as a USB-to-serial converter. It has a serial interface with TTL or RS232 signal levels, input from a standard PS2 style keyboard and output to a VGA or composite monitor. You can use it as a normal serial terminal with keyboard and display or as a single chip controller to add a video output to a Micromite or PICAXE project. This is a complete ASCII VT100 compatible video terminal in a single chip.

Terminal emulator vt100