The 9845 was HP's high-end technical desktop computer of the 1970s until the introduction of the 200 Series in 1981. The 9845 was the first HP computer to incorporate a twelve-inch CRT screen. Previous computers had only one or three line screens. The large monitor of the 9845 made program debugging and program listing much more convenient. It also provided (optional) graphics display for the first time, with a resolution of 560 x 455 dots. The 9845A came standard with a built-in mini-cartridge tape drive (217K capacity). A second tape drive was optional as was a built-in thermal printer (80 characters wide, 480 lines per minute and graphics capable).