Forums

Hi guys! My first post here. Thank you very much for your effort to keep SMS legacy alive! I´m a dev from Brazil and willing to contribute as much as I can.

I've done a test rom with a simple splash screen and it runs normally on Kega Fusion, Meka and Emulicious. But when I deploy to Mega Drive thru Krikzz Mega Everdrive X7 the screen flashes for a second and goes black. I followed the coding process from SteveXNA tutorials (which are superb! Congrats dude and thanks!)

There's anything missing in the code or It's an issue regarding Krikzz MegaEverdrive chips?

Cheers all!

More likely it's doing something incompatible with a Mega Drive.

Weird.. because the 80s and 90s games run normally. Maybe any detail in devkit on how the z80 and genesis vdp are activated or mode4 switch. The worst part is that I don’t have a real SMS hardware nor master everdrive to test ;( Maybe sverx has a workaround. Thanks!

Maxim wrote

More likely it's doing something incompatible with a Mega Drive.

The VDP control registers differ between the two so you have to be careful to set any "unused" or "always 1 or 0" bits just right else you may end up activating some Mega Drive feature.

I suspect that devkitSMS is not itself triggering this else every homebrew using it would fail on a Mega Drive. Can you post your source?

Sure! Actually there's nothing different I guess... I used your latest version tool (0.43) to convert the graphic (btw very nice tool!). Tiles psgaiden format and tilemap and palettes binary. Thanks again!

main.c (601 B)

main source

Well, it looks sensible enough to me... I'll let others have a go.

I found the problems. First my X7 bios was outdated and the SMS bios was forced to JP. I just set to none and bang. Everything runs fine now.

Once again thank you for your support and patience. I hope pretty soon have something playable to show.

Maxim wrote

Well, it looks sensible enough to me... I'll let others have a go.

good you found the culprit :)

a few suggestions:
- you can use assets2banks --singleheader option to have it generate a single header file
- you can load tiles/tilemap/palettes before turning screen on
- STM-compressed tilemaps are perfect for splash screen, and save a lot of ROM

great work so far!

Wow! Any suggestion of best practice coming from the lib creator is always considered ;) One last question before living you guys in peace for awhile: about the title/splash screen.. could I do an image DMA display to have access to at least 48 or all 64 colors avaiable? Cheers!

sverx wrote

good you found the culprit :)

a few suggestions:
- you can use assets2banks --singleheader option to have it generate a single header file
- you can load tiles/tilemap/palettes before turning screen on
- STM-compressed tilemaps are perfect for splash screen, and save a lot of ROM

great work so far!

You can't display more than 32 colors without changing palette mid-frame, which will likely cause screen artifacts (stray dots) on the screen.

To have 32 colors, you should use both palettes for background, which is possible. Unfortunately, I don't know of any image converter that supports dual palette, so you should probably create two separate images.

Author	Message
CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	devKitSMS and Krikzz MegaEverdrive X7 Posted: Thu Jan 09, 2020 8:05 pm
CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	Hi guys! My first post here. Thank you very much for your effort to keep SMS legacy alive! I´m a dev from Brazil and willing to contribute as much as I can. I've done a test rom with a simple splash screen and it runs normally on Kega Fusion, Meka and Emulicious. But when I deploy to Mega Drive thru Krikzz Mega Everdrive X7 the screen flashes for a second and goes black. I followed the coding process from SteveXNA tutorials (which are superb! Congrats dude and thanks!) There's anything missing in the code or It's an issue regarding Krikzz MegaEverdrive chips? Cheers all!

Maxim Site Admin Joined: 19 Oct 1999 Posts: 14734 Location: London	Posted: Thu Jan 09, 2020 9:27 pm
	More likely it's doing something incompatible with a Mega Drive.

CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	Posted: Thu Jan 09, 2020 9:37 pm
CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	Weird.. because the 80s and 90s games run normally. Maybe any detail in devkit on how the z80 and genesis vdp are activated or mode4 switch. The worst part is that I don’t have a real SMS hardware nor master everdrive to test ;( Maybe sverx has a workaround. Thanks! Maxim wrote More likely it's doing something incompatible with a Mega Drive.

Maxim Site Admin Joined: 19 Oct 1999 Posts: 14734 Location: London	Posted: Thu Jan 09, 2020 9:41 pm
	The VDP control registers differ between the two so you have to be careful to set any "unused" or "always 1 or 0" bits just right else you may end up activating some Mega Drive feature. I suspect that devkitSMS is not itself triggering this else every homebrew using it would fail on a Mega Drive. Can you post your source?

CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	Posted: Thu Jan 09, 2020 9:47 pm
CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	Sure! Actually there's nothing different I guess... I used your latest version tool (0.43) to convert the graphic (btw very nice tool!). Tiles psgaiden format and tilemap and palettes binary. Thanks again! main.c (601 B) main source

Maxim Site Admin Joined: 19 Oct 1999 Posts: 14734 Location: London	Posted: Thu Jan 09, 2020 10:01 pm
	Well, it looks sensible enough to me... I'll let others have a go.

CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	Posted: Fri Jan 10, 2020 3:43 am
CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	I found the problems. First my X7 bios was outdated and the SMS bios was forced to JP. I just set to none and bang. Everything runs fine now. Once again thank you for your support and patience. I hope pretty soon have something playable to show. Maxim wrote Well, it looks sensible enough to me... I'll let others have a go.

sverx Joined: 05 Sep 2013 Posts: 3823 Location: Stockholm, Sweden	Posted: Fri Jan 10, 2020 2:51 pm
	good you found the culprit :) a few suggestions: - you can use assets2banks --singleheader option to have it generate a single header file - you can load tiles/tilemap/palettes before turning screen on - STM-compressed tilemaps are perfect for splash screen, and save a lot of ROM great work so far!

CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	Posted: Fri Jan 10, 2020 5:05 pm
CRIAPOLIS Joined: 09 Jan 2020 Posts: 5 Location: Brazil	Wow! Any suggestion of best practice coming from the lib creator is always considered ;) One last question before living you guys in peace for awhile: about the title/splash screen.. could I do an image DMA display to have access to at least 48 or all 64 colors avaiable? Cheers! sverx wrote good you found the culprit :) a few suggestions: - you can use assets2banks --singleheader option to have it generate a single header file - you can load tiles/tilemap/palettes before turning screen on - STM-compressed tilemaps are perfect for splash screen, and save a lot of ROM great work so far!

sverx Joined: 05 Sep 2013 Posts: 3823 Location: Stockholm, Sweden	Posted: Fri Jan 10, 2020 5:25 pm
	You can't display more than 32 colors without changing palette mid-frame, which will likely cause screen artifacts (stray dots) on the screen. To have 32 colors, you should use both palettes for background, which is possible. Unfortunately, I don't know of any image converter that supports dual palette, so you should probably create two separate images.

Forums

View topic - devKitSMS and Krikzz MegaEverdrive X7