These are more than sufficient for simple control applications. I'm just wondering if I can run a small GUI on it driving an OLED display. That's what I'm gonna find out.
I'm confident you won't have any trouble at all doing that. 8KB RAM doesn't sound like much, but it's plenty fast enough to make up for it unless your OLED display is huge and your graphics are very complicated. It's roughly 50 times as fast as the original Macintosh, but with one sixteenth of the RAM, a combination that you may find favors IMGUI approaches. Popular OLED display controllers like the SSD1306BZ have their own framebuffers onboard, so you don't have to regenerate the pixels dozens of times a second to refresh the display the way you do for VGA or NTSC.
I'm confident you won't have any trouble at all doing that. 8KB RAM doesn't sound like much, but it's plenty fast enough to make up for it unless your OLED display is huge and your graphics are very complicated. It's roughly 50 times as fast as the original Macintosh, but with one sixteenth of the RAM, a combination that you may find favors IMGUI approaches. Popular OLED display controllers like the SSD1306BZ have their own framebuffers onboard, so you don't have to regenerate the pixels dozens of times a second to refresh the display the way you do for VGA or NTSC.