Search found 914 matches

by Oziphantom
Wed Sep 23, 2020 2:10 am
Forum: NESdev
Topic: 8-Way Scrolling Screen Compression Method?
Replies: 16
Views: 559

Re: 8-Way Scrolling Screen Compression Method?

MetaTiles are NESDev for Blocks and Blocks are form of compression.
by Oziphantom
Mon Sep 14, 2020 1:07 am
Forum: NESdev
Topic: index outside of label (intentionally) asm
Replies: 12
Views: 457

Re: index outside of label (intentionally) asm

backgroundPalette1: .res 4 backgroundPalette2: .res 4 backgroundPalette3: .res 4 backgroundPalette4: .res 4 ldy #15 @fillPalette: lda (paletteData), y sta backgroundPalette1, y dey bpl @fillPalette but is paletteData a vector point to the data or just an address, because if its an address you can d...
by Oziphantom
Fri Sep 11, 2020 11:54 pm
Forum: GBDev
Topic: OpenLara for GBA
Replies: 7
Views: 1275

Re: OpenLara for GBA

That is very impressive.
by Oziphantom
Wed Sep 09, 2020 5:17 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 11690

Re: Questions about NES programming and architecture

localization is mostly a economic decision and is down to the publisher. Something like an RPG where the story matters going EFIGS is kind of important, but Street Fighter II not so much. For example SFII keeps the Japanese voice samples, even Chun Li speaks Japanese even though she is Chinese, and ...
by Oziphantom
Tue Sep 08, 2020 7:43 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 11690

Re: Questions about NES programming and architecture

Nintendos Quality checks are not "this is a great game with stunning game-play" but more - The game can be completed - The game has a mostly standard button input system A = Accept, B = Cancel etc - The game follows software cautions so doesn't harm the console or cause issues - The game doesn't hav...
by Oziphantom
Mon Sep 07, 2020 10:20 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 11690

Re: Questions about NES programming and architecture

Pokun wrote:
Mon Sep 07, 2020 6:00 am
Supposedly the B flag doesn't even physically exist in P (no need to since there is no way to read P or check the B flag directly), but it exists in the copy of P that can be found on the stack after an IRQ happened.
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by Oziphantom
Mon Sep 07, 2020 12:18 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 11690

Re: Questions about NES programming and architecture

Nobody made a "6502 for NES programming" book, everybody will have learnt either on another system or those people that did just learn 6502 for NES will have read books from other machines first. There is no way to debug on a NES, they would have used either actual 6502 systems such as the Apple ][ ...
by Oziphantom
Sun Sep 06, 2020 2:25 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 11690

Re: Questions about NES programming and architecture

While being quite acustomed to 6502 programming, I've never actually used the decimal, do you know what it was used for on other machines? Same goes for the BRK instruction, from what I understand it's mainly used for debugging. This instruction seems rather obscure to me since it's actually a 1 by...
by Oziphantom
Sun Sep 06, 2020 2:24 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 11690

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 info...
by Oziphantom
Thu Sep 03, 2020 10:08 am
Forum: General Stuff
Topic: The learning process
Replies: 6
Views: 806

Re: The learning process

There are basically two ways people like to work. These broadly tend to fall into Male and Female "ways" but not really. Press every button and see what happens. I.e learn by doing, dive in and start experimenting ( classical Male fashion ) Read the instructions/all literature you can get your hands...
by Oziphantom
Wed Sep 02, 2020 4:34 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 11690

Re: Questions about NES programming and architecture

well imagine the PPU has a very simple CPU that only has operations to sort the graphics. Basically it has a small FSM that loops through the Sprite RAM, does y checks, then enters the number into a buffer Then when the scan line is drawn, it checks the sprite buffers X entries to see if this x pos ...
by Oziphantom
Tue Sep 01, 2020 8:16 am
Forum: NESdev
Topic: Ca65 syntax guide for 6502?
Replies: 5
Views: 490

Re: Ca65 syntax guide for 6502?

that is not CA65 that is 6502 LDA Value LDA #Value the first means value is an address and the second means it is a immediate number same with ADC #5 ; # is immediate address mode ADC 5 ; ZP address mode ADC 500 ; Abs address mode see any list of 6502 opcode for the list, although the best set is th...
by Oziphantom
Tue Sep 01, 2020 5:47 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 11690

Re: Questions about NES programming and architecture

the VIC-II chip can see 16.5K at once. However a screen takes 1K and a char set takes 2 K, leaving you with 13K for sprites. Hardly a limit. Its down to bandwidth, it could stall the CPU for the entire visible frame to get 2 bytes per 8 pixels but then the CPU would be limited to VBlank. However it ...
by Oziphantom
Tue Sep 01, 2020 1:36 am
Forum: NESdev
Topic: Questions about NES programming and architecture
Replies: 143
Views: 11690

Re: Questions about NES programming and architecture

The C64 and VIC-20 do this, and as a result are barely half the speed of the NES. The NES is 1.8 the C64 is 1±0.02. Its not barely half its clearly over half. This limits the VIC to being able to get 1 byte per clock. It does need more so it blocks the CPU to get 2 bytes per "cycle" every 8 lines a...
by Oziphantom
Sun Aug 30, 2020 4:36 am
Forum: SNESdev
Topic: Detecting...
Replies: 9
Views: 1008

Re: Detecting...

yeah you would need to with the "going to break stuff randomly" tricks and do multiple checks in multiple memory locations in multiple ways. Also using say a custom mapper layout will mess things up.