Ask HN: Monochrome LCD display (think TI-89) + HDMI?

Hey HN crew - Trying to cobble together a DIY portable digital typewriter, terminal. RaspPi, small external USB keyboard, and eInk display. Code in the sun. EInk doesn’t seem to be there yet, but I got to thinking- why not try out a monochrome LCD, like the screens on graphic calculators. Maybe I’m not searching in the right corners of Amazon or Alibaba, but I haven’t been able to find a black & white LCD screen with HDMI input. Has anyone been down this route and have suggestions? Gracias.