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by billygoat 128 days ago
Wait, there is an 800x480 display connected, but the thing only has 46k of RAM. There's no explanation of the display approach being used.

The extended graphics commands seem to allow X/Y positioning with an 8-bit color.

I think the picture shows an 80x25 screen?

What gives here? Anyone know what's going on?
2 comments
alnwlsn 128 days ago
The display controller they are using (RA8875 or RA8889) has several hundred KB of internal memory. So you can write to the screen and the image will "stay there" as it were, you don't have to store a framebuffer or keep writing out the image like with a CRT.
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jensgk 128 days ago
It probably has a character mapped display, so you can only display 256 different (ascii and graphics) characters in a memory mapped 80*25 = 2000 bytes display buffer.

EDIT: I can now see that is does have bit mapped graphics. It must have a built-in serial like terminal with graphics capabilities.

EDIT2: Probably using this chip: https://www.adafruit.com/product/1590

:-)

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