Search found 705 matches

by Sik
Tue Sep 18, 2018 4:33 pm
Forum: Megadrive/Genesis
Topic: Neat programming trick for optional operations
Replies: 2
Views: 63

Re: Neat programming trick for optional operations

Yep, ADD D0, D0 pushes the high bit of D0 into carry flag, which then can be checked with a branch. If you know the next bit to check is on the MSB and don't mind modifying the value it's faster than doing BTST (ADD.W is 4 cycles, BTST is 8 off the top of my head). The trick is normally used when re...
by Sik
Tue Sep 18, 2018 3:00 pm
Forum: Controls
Topic: Mega Mouse Usage
Replies: 20
Views: 3129

Re: Mega Mouse Usage

The drift issue would still happen without the hacked resolution (you can get the mouse to report a large enough motion to trigger the bug).
by Sik
Sun Sep 16, 2018 4:06 pm
Forum: Sound
Topic: Regarding the YM3438 on the Mega Drive...
Replies: 9
Views: 135

Re: Regarding the YM3438 on the Mega Drive...

Apparently, just like on YM2612 reads on any of the four possible addresses result on the status register so while the datasheet mentions you should only read the status with A0 = 0 and A1 = 0, they actually don't matter. Not in the version that got integrated into the ASIC in later Mega Drive mode...
by Sik
Sun Sep 16, 2018 1:11 am
Forum: Sound
Topic: Regarding the YM3438 on the Mega Drive...
Replies: 9
Views: 135

Re: Regarding the YM3438 on the Mega Drive...

Spamming reads on the status register causes the YM3438 go out of whack. This is why I was getting atrocious sounds out of my YM3438 chip. The YM2612 does not care if you spam the status register with reads. Too fast writes will disturb it but reads it doesn't care. oof, not yet another detail to w...
by Sik
Wed Sep 05, 2018 4:10 am
Forum: Exodus
Topic: Exodus 2.1 release soon (Now available!)
Replies: 27
Views: 972

Re: Exodus 2.1 release soon (Now available!)

My impression was that F-16 stuck to mode 2 for memory reasons - the framebuffer is pretty large (may not have even fit in VRAM if using mode 4), and needing to write only 25% the amount of bytes is a plus for performance. The simpler capabilities of the TMS9918 modes are actually a benefit in this ...
by Sik
Tue Sep 04, 2018 1:39 pm
Forum: Exodus
Topic: Exodus 2.1 release soon (Now available!)
Replies: 27
Views: 972

Re: Exodus 2.1 release soon (Now available!)

MD model 3 also handles TAS properly (which is why Gargolyes hangs up - it needs TAS to fail to write), and if I recall correctly one of the goals was to emulate multiple model eventually? So TAS needs to be emulated either way. Also the reason why that game breaks is... pretty silly (1. it was mean...
by Sik
Tue Sep 04, 2018 1:23 am
Forum: Exodus
Topic: Exodus 2.1 release soon (Now available!)
Replies: 27
Views: 972

Re: Exodus 2.1 release soon (Now available!)

The Master System VDP also has a revisions with rather significant changes (fixes the MAG bit and adds the taller video modes), and there are PAL games relying on those (especially Codemasters stuff), while Mega Drive takes a different path (MAG is outright removed completely rather than fixed), and...
by Sik
Thu Aug 30, 2018 12:28 pm
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 233
Views: 14689

Re: Tänzer, a "ninja" game (Dev Diary thread)

It's "simple" only if you have at least a vague idea about working with electronics... But yeah, a region mod with switches is worth it (especially if the switches are exposed outside instead of needing to open the console). There are people who are willing to do the mod too. Just beware of the ship...
by Sik
Tue Aug 28, 2018 8:49 pm
Forum: Megadrive/Genesis
Topic: 68000 programming optimization tips? (for speed)
Replies: 27
Views: 2980

Re: 68000 programming optimization tips? (for speed)

I think it's meant to return -1, 0 or +1. At least that's what sign functions usually do.

Still trying to get my head around it, mind you (mainly the NEGX).
by Sik
Mon Aug 27, 2018 12:58 pm
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 233
Views: 14689

Re: Tänzer, a "ninja" game (Dev Diary thread)

Erm...

Code: Select all

/**
 *  \typedef vu16
 *      volatile 16 bits unsigned integer.
 */
typedef volatile u16 vu16;
Though wait, does volatile actually work in typedef or is it meant to be ignored?
by Sik
Sun Aug 26, 2018 3:38 pm
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 233
Views: 14689

Re: Tänzer, a "ninja" game (Dev Diary thread)

Just to make it clear: VDP never lets go of the CRAM bus, so any writes to the palettes will always result in CRAM dots, no exception. The best you can do is try to hide them in border area, which is what games do in general. Anyway, back to the problem... that isn't helpful at all. May need to post...
by Sik
Thu Aug 02, 2018 8:09 pm
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 233
Views: 14689

Re: Tänzer, a "ninja" game (Dev Diary thread)

Pressing Start and another button at the same time is hell (at least in the case of an action game), you need to change the position of your fingers since the Start button is not ready to press while in the usual stance. That's something you want to avoid at all costs. Let's throw more gasoline to t...
by Sik
Thu Aug 02, 2018 7:50 am
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 233
Views: 14689

Re: Tänzer, a "ninja" game (Dev Diary thread)

I mean, going into the options menu every time was the norm :​v And people may want to change other stuff anyway (e.g. if you include a difficulty setting you can be sure that several players will change the default), once you consider that going into the menu to change controls isn't that much of a...
by Sik
Wed Aug 01, 2018 10:35 pm
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 233
Views: 14689

Re: Tänzer, a "ninja" game (Dev Diary thread)

When I saw "Cycle Selected Transmutation Attack" I honestly thought it meant being able to change it while paused (like Revenge of Shinobi does for the ninjitsu). I'd imagine you wouldn't be changing the attack often. Then the 6-button controller could be used as an enhancement to let you change it ...
by Sik
Wed Aug 01, 2018 8:23 am
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 233
Views: 14689

Re: Tänzer, a "ninja" game (Dev Diary thread)

A stage select (even rudimentary) would be needed for debugging though, right?

Actually one benefit of implementing menus early is that it makes it easier to implement stuff you'll need while making the game.