Perhaps it's getting a bit #gameboy heavy over here, but you've got to have a hobby. Fixed a bug in which I accounted twice for the background scrolling, added some support for ROM and RAM banking, and we have a proper Zelda intro. Link can wake up now. #emudev #odinlang

I would for now suggest that Link stays asleep a little longer, but it's getting there. Silly mistakes in the MBC1 handling resulted in garbage before, but now we have some content at least. #gameboy #emudev #odinlang

Fixed a whole bunch of sprite/object drawing behaviours today. Still not passing the acid2 tests, but at least I can play Dr. Mario 😁.
I guess it's on to some more cartridge support to be able to play other games, and trying to pass some more validation roms. #gameboy #emudev #odinlang

Okay, Mario no longer has a split personality, and the Koopas no long moonwalk (which is a good thing). Still some scanline glitches and currently running into some strange issues when trying to support background and object palettes, but that's for another day. #gameboy #emulator #odinlang

Okay, so the sprite transparency issue bugged me, whatchagonnadoaboutit? But that's it for tonight. I can live with the flips not being handled correctly ...

And of course as soon as you decide to call it quits, the solution comes to you.

That is more like it. Background tile selection seems fixed. Now to figure out what I got wrong about the window scrolling and column drawing. Plenty of things to fix still, but it's starting to look recognizable. #gameboy #emulator #odinlang

I'm not going to argue that this looks entirely correct, but I'm still calling it progress. #gameboy #emulator #odin

I can't overstate how good it is to finally see this. Spent quite some time trying to figure out what was wrong with my timer implementation. And while I'm sure there are some edge-cases I'm not handling properly, at least the test rom now succeeds. #gameboy #emulator #odin

And as is so often the case, the moment you decide to give up for the day is the moment you figure out what's wrong. So yeah, fixed. With respect to the display coordinates, sprites have an 8-pixel boundary on the x-axis, and a 16 (!!) pixel boundary on the y-axis for their own coordinates.

Some further progress. Sprites now render on top of the background, so we finally see the gameplay demo. Although there does seem to be an offset coming from somewhere, causing the sprites to appear one tile-height lower. But that's for tomorrow ...
#gameboy #emulator #odin

I cannot escape the feeling that my display implementation has some issues still ...
#gameboy #emulator #odin #imgui

After a bit of bug hunting and fixing during the week, I finally have OAM data up and running as well. So all the ingredients are there to start assembling the final display results and play some tetris. #gameboy #emulator #odin #dearimgui

And for those wondering, it is so "slow" because showing the full memory for every frame is not the best idea. And yes, it does eventually get into the gameplay demo loop. (Note, the graphics are not yet fully implemented)
Also, BSky seems to be doing quite a number on the video compression ...

Wait for it ... wait for iiiittt ... tadaaaaa.
We have Tetris startup. Hunted down a bunch of minor issues, but things are starting to take shape.
#gameboy #emulator #odin

It may just be me, but something doesn't look quite right about those Tetris tiles in my Gameboy emulator. I guess it's progress, but I also have something new to debug it seems. I'm suspecting there is something wrong about my timings or my interrupts.