Search found 338 matches

by cero
Thu May 12, 2016 10:48 am
Forum: SGDK
Topic: GCC inline asm tutorial
Replies: 4
Views: 15609

GCC inline asm tutorial

https://github.com/0xAX/linux-insides/b ... heory-3.md

Thought I'd share the link. Can this be stickied for new users?
by cero
Thu May 12, 2016 7:43 am
Forum: Video Display Processor
Topic: When is the collision bit cleared?
Replies: 14
Views: 14575

Re: When is the collision bit cleared?

So it is not cleared any time during vblank? (automatically, that is)
by cero
Thu May 12, 2016 7:40 am
Forum: SGDK
Topic: DMA queue clash with early frame code
Replies: 12
Views: 6416

Re: DMA queue clash with early frame code

They may be disabled long enough for the framerate to drop to 30fps temporarily. But they are always enabled before waitVSync.
by cero
Wed May 11, 2016 2:36 pm
Forum: SGDK
Topic: DMA queue clash with early frame code
Replies: 12
Views: 6416

Re: DMA queue clash with early frame code

I did not set any limit.
by cero
Wed May 11, 2016 12:27 pm
Forum: SGDK
Topic: DMA queue clash with early frame code
Replies: 12
Views: 6416

Re: DMA queue clash with early frame code

According to the code, it's not possible for the queue to have contents after waitVSync, yet that's what I repeatably saw. This is a very interesting bug.
by cero
Wed May 11, 2016 10:33 am
Forum: SGDK
Topic: DMA queue clash with early frame code
Replies: 12
Views: 6416

Re: DMA queue clash with early frame code

Indeed, on some frames the DMA queue is not empty at the start. Trying to clear it now.
by cero
Wed May 11, 2016 9:58 am
Forum: Video Display Processor
Topic: When is the collision bit cleared?
Replies: 14
Views: 14575

When is the collision bit cleared?

The status register has a sprite collision bit. When exactly is it cleared? sega2f is silent on this one.
by cero
Wed May 11, 2016 7:56 am
Forum: SGDK
Topic: XGM driver hangs during fades
Replies: 12
Views: 6561

Re: XGM driver hangs during fades

Thanks. master doesn't build due to multiple issues with vram.c, but I could just pull the relevant commits. I confirm the XGM issue is fixed.
by cero
Wed May 11, 2016 7:55 am
Forum: SGDK
Topic: DMA queue clash with early frame code
Replies: 12
Views: 6416

Re: DMA queue clash with early frame code

Indeed, yet it has an effect. On multiple emulators, not yet tested on hw. It must have something to do with the DMA due to which tiles get corrupted - ones right after the final DMA copy. How would you track this? edit: Another idea. Is the following possible: - the frame takes just slightly too lo...
by cero
Tue May 10, 2016 7:02 pm
Forum: SGDK
Topic: DMA queue clash with early frame code
Replies: 12
Views: 6416

Re: DMA queue clash with early frame code

No, just a normal ROM-to-VRAM copy. And the DMA queue is the only DMA I use, so how could that fix it? edit: The corruption was visible in the couple tiles following the last DMA target. As if the DMA copy randomly wrote too much, or if it interrupted another VDP call, leaving the dest address there...
by cero
Tue May 10, 2016 3:59 pm
Forum: SGDK
Topic: DMA queue clash with early frame code
Replies: 12
Views: 6416

Re: DMA queue clash with early frame code

Yep, sticking VDP_waitDMACompletion() at the frame start seems to fix the corruption.
by cero
Tue May 10, 2016 3:47 pm
Forum: SGDK
Topic: DMA queue clash with early frame code
Replies: 12
Views: 6416

DMA queue clash with early frame code

Is the following issue possible? - use the DMA queue to sync a few kb - the v-int callback does not wait for DMA - thus the frame code can start *while the DMA is going* - then, if there's early frame code that accesses the VDP, even with interrupts disabled, it can conflict and blow up I believe I'...
by cero
Tue May 10, 2016 2:51 pm
Forum: SGDK
Topic: XGM driver hangs during fades
Replies: 12
Views: 6561

Re: XGM driver hangs during fades

Stef, can you post the patch somewhere? I'd like to keep my sgdk in sync with the official fix, and I'd need this to work.
by cero
Mon May 09, 2016 2:58 pm
Forum: SGDK
Topic: Multitap docs seem wrong
Replies: 0
Views: 12562

Multitap docs seem wrong

Quoting from docs: By default ports are configured to only enable support for joypads, unless<br> * a pad is not detected. In that case, a multitap or mouse is enabled if<br> * present.<br> This only seems to be the case for the EA multitap. Using the Sega multitap, the portSupport variable remains ...
by cero
Tue May 03, 2016 4:40 pm
Forum: SGDK
Topic: XGM driver hangs during fades
Replies: 12
Views: 6561

Re: XGM driver hangs during fades

I don't see it on github?

It's perfectly fine for master to be broken, or you could use a different branch if it's invasive. There are many people waiting for this new version, even if it's broken right now, please share the code.