I'm not intimately familiar with the Game Boy's video signals, but I wonder: why the fancy microcontroller and digital-to-analog converters? The Terminalscope just uses a couple of op-amps to generate the horizontal and vertical sweeps. The microcontroller doesn't have to worry about moving the beam, so the refresh rate is very high and there's no flicker.
Maybe I should try this with my old Game Boy: the LCD is starting to die anyway...
As noted in the comments of that post, I'm doing a raster display with vector display techniques. Opamp sweeps are indeed a more sensible way of rastering, but the internal DACs on this microcontroller are fast enough to keep up anyway.
What's killing the refresh rate is the settling time for the (crappy) external dac doing the 4-shade colour. Your terminal application only deals with beam on/beam blanked so you can run it a lot faster.
By all means give it a go, it's a pretty satisfying project. I have no doubt you can improve on my version.
If you used an opamp sweep for one of the rastering dimensions (probably the horizontal), wouldn't that free up one of the DACs so you could use it for the shading?
The model of a good HN post. Not only does it do something interesting to geeks, but, unlike "Star Wars On A Floppy Drive", actually takes the time to explain how it worked. Less cat - photos - in - geek-post - clothing. More like this.
Also, coolest thing I've seen done yet with a Salae probe. Those things are cheap, tiny, cool looking, and make great gifts; we've given them to job candidates before when things didn't work out.
I'm not intimately familiar with the Game Boy's video signals, but I wonder: why the fancy microcontroller and digital-to-analog converters? The Terminalscope just uses a couple of op-amps to generate the horizontal and vertical sweeps. The microcontroller doesn't have to worry about moving the beam, so the refresh rate is very high and there's no flicker.
Maybe I should try this with my old Game Boy: the LCD is starting to die anyway...