The NE5150 / 5151 / 5152 are triple 4-bit DACs intended for use in graphic display systems. They are a high-performance, yet cost-effective means of interfacing digital memory and a CRT. The NE5150/5152 are single integrated circuit chips containing special input buffers, an ECL static RAM, high-speed latches, and three 4-bit DACs. The input buffers are user-selectable as either ECL or TTL compatible for the NE5150. The NE5152 is similar to the NE5150, but is TTL compatible only, and operates off a single +5V supply. The RAM is organized as 16 x 12 so that 16 "color words" can be downloaded from the pixel memory into the chip memory. Each 12-bit word represents 4-bits of red, 4-bits of green, and 4-bits of blue information. This system gives 4096 possible colors. The RAM is fast enough to completely reload during the horizontal retrace time.
