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hoglet67 / RGBtoHDMI

Bare-metal Raspberry Pi project that provides pixel-perfect sampling of Retro Computer RGB/YUV video and conversion to HDMI
GNU General Public License v3.0
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Mastersystem / MegaDrive / Gensis RGBtoHDMI #285

Closed ryanm101 closed 1 year ago

ryanm101 commented 2 years ago

According to: https://segaretro.org/Sega_Mega_Drive/Technical_specifications & https://segaretro.org/Sega_Mega_Drive/Palettes_and_CRAM its 9bit RGB (3bits per colour)

https://console5.com/techwiki/images//8/8b/Mega_Drive_1_-_VA3_-_Audio%2C_Video_%28Sheet_2%29.png shows the pins from the IC. Might need an ADC to convert 1st?

Master System https://segaretro.org/Sega_Master_System/Technical_specifications & https://segaretro.org/Palette#Master_System_palette https://console5.com/techwiki/images/0/0e/SMS_Schematic_-_IC_BOARD_PB_PAL_VA1_-_171-5534_-_1_of_2.png https://console5.com/techwiki/images/5/59/SMS_Schematic_-_IC_BOARD_PB_PAL_VA1_-_171-5534_-_2_of_2.png

IanSB commented 2 years ago

Although it has a low enough number of levels (9 bits per pixel) the output from the chip is already in analog. The existing analog board can only cope with 4 levels each for RGB and you would need an A to D that could accurately extract the 8 levels each from the RGB signals.

ryanm101 commented 2 years ago

Would ADV7401 do the trick?

ryanm101 commented 2 years ago

I've found and ordered a TVP7002 in the hope that will do the job

davedoc1984 commented 2 years ago

What about the Audio though?

c0pperdragon commented 9 months ago

The Sega Master System has a simple 6-bit palette with 2 bits per R,G,B channel. So 4 levels each, which should be possible with the analog board and mounted extra comparator. Pixel clock is also quite moderate. (I just looked into this to make sure that there is no need to come up with a Lumacode adapter ;-) )