DR-1240 Green Screen TTL

The Leading Edge model DR‐1240 Green Screen TTL Monitor was a green screen monochrome monitor offered by the Leading Edge computer company. When introduced in 1983, this model and its sister model, the amber screen DR‐1240 Amber Screen TTL Monitor were often paired with the Leading Edge Model D XT computer. Given the DR‐1240's model number includes the D designation, this indicates that it was manufactured by the South Korean Daewoo company for Leading Edge Products INC of Canton, Massachusetts.

As indicated in the name of the monitor, the DR‐1240 utilizes TTL (transistor‐transistor logic) digital signal processing to process both the logic function and the amplification function.

The physical look of the monitor is distinctly 1980's with a classic "computer beige" colored plastic case. The monitor's MDA cable and power cable are both permanently fixed to the monitor, this can cause problems as the equipment ages since twisting and bending of the cables may cause metal fatigue in the wires over time, leading to intermittent performance and / or operational issues. On the bottom rear of the monitor is an 11‐position kickstand. In the kickstand's maximum extension, the monitor is tilted forward toward the user making the monitor have more of a flat 90 degree viewing angle. The kickstand is removable by unscrewing four screws on the bottom of the monitor and carefully withdrawing the stand's two positioning pistons.

Further back on the rear of the monitor, the user can find three potentiometers accessible on the outside of the case: vertical hold, vertical size, and vertical LIN with black adjustment knobs. The knobs are almost flush with the case to prevent accidental adjustments so it's best to use a flat‐head screwdriver to make adjustments if needed.

Back at the front of the monitor, one can find the power rocker‐switch, red power LED indicator, and brightness and contrast knobs.

Opening the case reveals a 12‐inch Orion CRT. The logic board is placed in an unconventional orientation at the top of the monitor and at the back of the CRT tube, the neck board has a very small physical footprint with heavy components of the monitor such as the flyback transformer mounted on the bottom of the case to a sturdy metal plate.