What is it?

This VGA card provides high-resolution video, with 65536 colors, and a blazing fast parallel interface for writing large images or drawing commands.

This board uses a dedicated video chip, the RA8875, to accelerate graphics, handle memory, and generate the video signal. Although this chip was designed for LCD displays, it works great for VGA as well. This board also features a real video DAC, the THS8135, instead of a simple resistor network. The bus interface is passed through a level shifter, so the RA8875 can be safely accessed from 5v logic.

If you are looking for high-quality and cheap video output for your project, you've come to the right place; I am not aware of any other product on Tindie which provides this high of a resolution, with this many colors, for this low of a price.

• 800x480 pixel resolution
• 65536 colors
• 8-bit 8080/Z80 compatible bus, 5v-compatible
• Overclocked the data bus up to 167.9 Mbps
  • Designed for 55ns access time
• All basic draw functions like rectangles, lines, circles
• Hardware scrolling
• ROM Font offloads memory demands on host processor
• Arduino library
• Multiple supported resolutions
• Excellent at displaying images

Why did you make it?

I needed high-quality video for my Teensy 4.1 computer (which I also sell), and I had this idea that perhaps the RA8875 could do VGA, too. So I tried it, and it worked. I built this because nothing else really met the specifications I wanted for high resolution video, nor the high write speeds needed for high quality games.

I built this over an FPGA-based solution, for a few reasons:

• The FPGA configuration may not provide a standard protocol
• Speed limitations due to it not being "real" hardware
• Higher cost for FPGA

You see this reflected in this product: The interface is very standard, the system is extremely fast, and all of it is provided at a very reasonable price.

What makes it special?

This board provides a higher resolution than all but one product I've thusfar seen on Tindie, without sacrificing its excellent color depth, all while using a simple 8-bit interface. All of this is provided at a fraction of the cost of many other boards available. This board really does have it all; you really can have your cake and eat it too.

Other notes (PLEASE READ)

The current board design has two very minor defects:

• In certain situations where there is white on black, especially after long text, there can be some light streaking on the screen, but this is not very noticeable and does not seem to appear in images.
• The silkscreen on the back overlaps with some PTH pins, cutting the text. This does not affect performance, but is worth noting. It will be fixed in the next PCB version.