RA8875 Parallel VGA Card

The RA8875 Parallel VGA Card is a small card which provides 800x480 pixel VGA output, using an 8-bit, 5v-compatible 8080-style data bus. It uses the RA8875, which comes with many useful features for drawing, and includes built-in fonts, hardware scrolling, multiple layers, etc.

Detailed Specifications

• Up to 480x800 pixel display
• 16-bit color (RGB565)
  • Optionally, 8-bit color can be selected to use two drawing layers, and to improve bitmap draw time
• Video modes can be selected or designed
  • RA8875 allows configuring of all VGA regions, as well as hsync and vsync polarity. Multiple resolutions and pixel clocks may be selected
  • Recommended settings use a 40Mhz pixel clock
• 8-bit parallel data bus for fast writing
  • Overclocked to over 167.9Mbps with stable writing in tests
  • Minimum cycle time of 55ns (see RA8875 datasheet)
  • 5v compatible
  • 8080-style control signals: nWAIT, nWR, nRD, nSEL
  • Z80 and 8080 compatible design

This board is designed to work with the Teensy_4.1_Computer, and is a convenient way of adding video output to the Teensy computer.