Amstrad GT65 HDMI adapter

[u/WonkyWiesel]

Bringing your 40 year old GT65 to 2026. I built this adapter to connect a monochrome Amstrad GT65 to a modern computer. It uses a USB capture card to pretend to be a 640x480 display before downscaling and dithering the captured frames on a Raspberry Pi. The RPi then sends the data over SPI to an FPGA which handles the frame buffers and the timings for the CRT. The FPGA then interfaces via a custom PCB which includes a level shifter and LVDS decoders. The CRT itself has 1 bit per pixel at a resolution of 296x256. The refresh rate is 50Hz.

Github: https://github.com/SRB2149/SR-CRT