sinclair spectrum 48K implementation on $3 China board stm32f401ccu6
video: https://www.youtube.com/watch?v=2MMqiwxWd3s
- Pin a9 - video out
- Pin b8 - audio
- Pin a3 - sd card cs
- Pin a5 - sd card clk
- Pin a6 - sd card d0 (DO)
- Pin a7 - sd card cmd (DI)
- Pin b6 tty debug output 115200