Search found 4342 matches

by Dwedit
Fri Sep 18, 2020 9:52 pm
Forum: General Stuff
Topic: How to limit 60 FPS in a loop?
Replies: 7
Views: 172

Re: How to limit 60 FPS in a loop?

Happy case: 60FPS refresh rate, 60FPS gameplay speed. You use Present (from Direct3D/DXGI) to update the screen. It enqueues a screen update, and waits for vsync (with no unnecessary CPU usage) if there is already an update pending. Less happy case: Something that's not 60FPS as the refresh rate. Us...
by Dwedit
Fri Sep 11, 2020 6:55 pm
Forum: NESdev
Topic: constants with bitwise logic
Replies: 8
Views: 244

Re: constants with bitwise logic

I once had to simulate Logical Or in a script where you could only use the basic arithmetic operators.

Then you use the rules:
AND(x,y) = x * y
NOT(x) = (1 - x)

From those, you derive OR:

OR(x,y) = NOT(AND(NOT(x), NOT(y))
OR(x,y) = (1 - (1 - x) * (1 - y))
by Dwedit
Tue Sep 08, 2020 8:57 pm
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 8773

Re: Questions about NES programming and architecture

Some PAL games were in other European languages, and Kirby's Adventure had a French release for Canada.
by Dwedit
Sun Sep 06, 2020 5:04 pm
Forum: phpBB Issues
Topic: The [code] tag should not have its height limited
Replies: 9
Views: 872

Re: The [code] tag should not have its height limited

Perhaps nesdev should switch to a host that's actually administrated by someone who isn't absentee?
by Dwedit
Sun Sep 06, 2020 8:07 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 8773

Re: Questions about NES programming and architecture

Atari 2600 games had Decimal Mode available, so they used it. If you look at the disassembly of Dragster, it uses Decimal Mode for all the game's math.
by Dwedit
Sat Sep 05, 2020 10:41 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 8773

Re: Questions about NES programming and architecture

Not only do games clear decimal mode at bootup, they often disable interrupts too. Turns out that the initial power-on state is to have interrupts disabled, so disabling interrupts doesn't do much. May be useful though if the game wants to jump back to the power-on code to reset the game. More infor...
by Dwedit
Wed Sep 02, 2020 7:06 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 8773

Re: Questions about NES programming and architecture

The buffer isn't a whole scanline, just 16 pixels. It's refilled every time it goes down to 8 pixels.
by Dwedit
Mon Aug 31, 2020 6:09 pm
Forum: General Stuff
Topic: Strange Contra glitch?
Replies: 4
Views: 459

Re: Strange Contra glitch?

by Dwedit
Tue Aug 25, 2020 12:21 pm
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 8773

Re: Questions about NES programming and architecture

It didn't help that the FDS has an unconditional 7 second load time any time files from the disk are read, unless you use specific trickery to bypass the BIOS load routines (declare fewer files on the disk, then read past them manually). Anyway, back to the diagram. The disk drive doesn't directly m...
by Dwedit
Mon Aug 24, 2020 9:55 pm
Forum: General Stuff
Topic: Looks like NESCartDB is down (again)...
Replies: 56
Views: 21963

Re: Looks like NESCartDB is down (again)...

lidnariq wrote:
Mon Aug 24, 2020 8:46 pm
The XML file that nesCartDB hosted is the Nestopia cart database format. It's not the full set of data in the actual DB.
Yeah, I noticed it was missing PRG/CHR chip manufacturers and stuff like that.
by Dwedit
Mon Aug 24, 2020 9:37 pm
Forum: General Stuff
Topic: Looks like NESCartDB is down (again)...
Replies: 56
Views: 21963

Re: Looks like NESCartDB is down (again)...

The database XML file, from the site. 2017 version.
If you want to do something in C# with this database, you can use some tools to autogenerate C# classes, and deserialze the entire database to a typed object.
by Dwedit
Mon Aug 24, 2020 8:05 pm
Forum: General Stuff
Topic: Looks like NESCartDB is down (again)...
Replies: 56
Views: 21963

Re: Looks like NESCartDB is down (again)...

As compressed XML, it's about 300K. But there are probably more efficient ways to encode the same data.
by Dwedit
Mon Aug 24, 2020 7:54 pm
Forum: General Stuff
Topic: Looks like NESCartDB is down (again)...
Replies: 56
Views: 21963

Re: Looks like NESCartDB is down (again)...

I still think it would be best as a client-side javascript thing, so you could host it on any site that allows static content, or run it from your hard drive.
by Dwedit
Sat Aug 22, 2020 12:19 pm
Forum: General Stuff
Topic: Looks like NESCartDB is down (again)...
Replies: 56
Views: 21963

Re: Looks like NESCartDB is down (again)...

I have the XML database from 2017, anyone got a newer copy?
by Dwedit
Mon Aug 17, 2020 3:34 pm
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 8773

Re: Questions about NES programming and architecture

Address range for the PPU's RAM should be $2000-$2FFF, as the $3000+ range is an incomplete memory mirror that would overlap the palette area.

Maybe stick the Palette inside of that PPU box as well.