Difference between revisions of "RA8875 Parallel VGA Card"
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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. |
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. |
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| − | == Overall Design == |
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| − | [[File:Teensy41_Computer_Audio_circuit.png|thumb|Teensy 4.1 Computer audio circuit|600px]] |
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Revision as of 15:22, 31 August 2024
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.