Christopher Smith wrote: The Retrographics card adds Tektronix graphics capability to the text terminal it is fitted to. It fits between the serial port and the terminal's main board and intercepts incoming characters. It will normally pass incoming characters straight to the main board, but when it sees the Tektronix start code, it will start processing the incoming characters as graphics commands and updating its own video RAM. The video output of this card and the main board are overlaid. Try testing your card by typing: Ctrl-] to enter Vector Mode. space ` space @ [initialize to (0,0)] 8 k space @ [draw to (0,779)] 8 k ? RUB [draw to (1023,779)] space ` ? RUB [draw to (1023,0)] space ` space @ [draw to (0,0)] 8 k ? RUB [draw to (1023,779)] space ` ? RUB [draw to (1023, 0)] 8 k space @ [draw to (0,779)] This should draw a rectangle with diagonals. - Paul