#Retroputer #FPGA Update
Bought a 2.4" TFT ILI9341 from @adafruit and connected it up via 4-line SPI using #Alchitry Br (breakout board). I added an I/O device so the CPU can send D/C select bits and data bytes using a FIFO buffer.
After a bit of a false start (involved adapting Adafruit's init sequence and experimentation), we have something coherent on the screen!
Super slow to fill the screen w/ #BASIC (using OUT commands), but validates that my understanding mostly matches reality. Woot!
The BASIC program is a whole lot of OUT statements... and is NOT how one would actually generate a screen, but does let me test out the init sequence & generate screen data w/o waiting for a ~15-20m rebuild of the FPGA.
Kinda funny the layers involved—partially implemented BASIC using a partially implemented KERNEL, all written using a custom assembly language, running on a mostly implemented CPU on an FPGA, talking to a display that's connected via some very tenuous wiring (not soldered yet!)
Was originally just planning on using the TFT to debug the frame buffer logic (which is next to write) while generating #Retroputer's screen… (I _think_ this will be easier to debug any VGA output I add if I know the logic to build the frame buffer is correct.)
But it's such a cute screen that I'm toying with the idea of making a mini-Retroputer with a tiny keyboard and case.
I think that would be retro-licious.
Kerri Shotts