Search for "LCD firmware" repositories if you are using an Arduino or Raspberry Pi to interface with the screen.
Confirm the firmware is specifically for 1024 x 768 pixels. Flashing the wrong resolution firmware can lead to a "black screen" or "out of range" error. Download 8501 031A 1024 768 zip
Visit the official support page of the manufacturer (e.g., NEC Display Solutions) and enter the code into their "Downloads" or "Legacy Products" section. Search for "LCD firmware" repositories if you are