nesdev.com

Each time the 6502 needs to get something from memory, that's 1 additional cycle. And there's a minimum of 2 cycles for some reason, so the first 2 bytes of the instruction are already available. Examples TAX, TXA, ASL A, etc. are all 2 cycles because they don't need any additional memory access LDA...

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...

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))

Some PAL games were in other European languages, and Kirby's Adventure had a French release for Canada.

Perhaps nesdev should switch to a host that's actually administrated by someone who isn't absentee?

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.

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...

The buffer isn't a whole scanline, just 16 pixels. It's refilled every time it goes down to 8 pixels.

Crazy stuff sometimes happens.

https://www.twitch.tv/nescardinality/cl ... ntBeeDxCat

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...

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.

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.

As compressed XML, it's about 300K. But there are probably more efficient ways to encode the same data.

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.

I have the XML database from 2017, anyone got a newer copy?