The Hitachi HD6340RP is a programmable CRT controller (CRTC) LSI. It's designed to generate the timing signals necessary to control raster-scan CRT displays. This chip was commonly used in various computer systems and arcade machines during the 1980s.

Applications

• Video display controllers in early personal computers
• Arcade game video hardware
• Graphics terminals
• Industrial control systems with CRT displays

Features

• Programmable horizontal and vertical timing
• Supports interlaced and non-interlaced display modes
• Generates horizontal and vertical sync signals
• Provides cursor control signals
• Offers light pen input capability
• Supports direct memory access (DMA) for display refresh
• Character or graphic mode operation

Benefits

• Flexibility in configuring display parameters
• Reduced system component count by integrating display control functions
• Enables the creation of custom display formats
• Simplified interface to display memory

Additional Details

The HD6340RP works by generating timing signals that control the scanning of the electron beam in a CRT. These signals include horizontal sync (HSYNC), vertical sync (VSYNC), and blanking signals. The chip is programmed via its internal registers, which determine the display resolution, refresh rate, and other parameters. It is usually used in conjunction with video RAM (VRAM) to store the image data that is displayed on the CRT.

This chip interfaces with the CPU through a parallel data bus, allowing the CPU to program the various registers within the HD6340RP to configure the display. It also supports DMA, enabling it to directly access the display memory without CPU intervention, improving overall system performance.

The HD6340RP can be used in both character mode, where the display is composed of predefined characters, and graphics mode, where individual pixels can be controlled. The choice of mode depends on the specific application requirements and the desired level of graphical detail.

Due to its age, sourcing this chip can be difficult, and it's generally found in vintage computer systems or through electronic surplus vendors. Emulation is often used in modern systems to replicate the functionality of the HD6340RP.