Video output is adapted for a 5" TFT-LCD module 800x480 Type SH500Q01Z (Ilitek ILI6122)
Sipeed sells a 5 inch LCD for the Tang Nano 20k. This LCD has a resultion of 800x480 pixels and attaches directly to the Tang Nano 20k without using the HDMI connector. This is supported by all cores. The Tang 20k, 60k and 138k Pro additionally comes with a built-in I2S DAC and audio amplifier which comes in handy in this setup to add sound output.
Note
TN20k: No Dualshock, no D9 retro Joystick, no external RS232 support
For actual board setup also have a look at the VIC20 pages.
Pinmap TN20k Interfaces LCD Output M0S Dock, LCD, Speaker
Important
To enable the LCD Interface the tiny jumper J17 (near Button Key1 ) need to be plugged to position 1 + 2.