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It's slow even with DMA. The original iPhone was snappier than this.

The original iPhone was far more powerful than this hardware.

Typically these SPI screens only work up to 50MHz (which is already way out of spec, which is often 15MHz), there is 5M bits in 640x480x16 so you won't get more than 10fps no matter what you do rendering side.

Which is why they often also offer 8 bit serial interface. I guess one can use it with the PIO on rp2040.

Edit: whoops it's only 320x240. Not sure how fast are they are running it.

The original Mac was also snappier.

The original Mac was BW and didn’t do the same level of animation.

Of course a snappy interface is always more important than visual flair, but I imagine this is more a tech demo than anything else.

The original Mac was mostly Assembly for the graphics code.

For an example of a faster demo, see my Slint backend for the Teensy MicroMod:

https://twitter.com/charlesstrahan/status/163002622435647488...

Now, admittedly, this is 600 MHz beast (the NXP i.MX RT1062). But I’d like to think it’s still impressive for the hardware involved.

As mentioned in the Twitter thread, to eke out the performance I had to implement an 8-bit parallel bus using FlexIO along with DMA (all written in Rust) — but with that implemented, the display is pretty zippy.

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