NA » NES Programming

NES Programming Organized - Nerdy Nights

Jun 10, 2016 at 6:54:26 AM

freeman.pixelz (0)

< Cherub >

Posts: 5 - Joined: 04/08/2016

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Thanks to this group, I have developed 3 music demos on NES/Famicom available here on github. The source asm files are available and you can see how I developed the sound engine.

Edited: 03/27/2017 at 03:05 PM by freeman.pixelz

Jun 16, 2016 at 11:13:15 AM

LayneFelix (0)

< Cherub >

Posts: 1 - Joined: 06/15/2016

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Hi..i am not much familiar about its hardware but as per my knowledge some programmer back in the late 70s or early 80s made up the term using that idea from the novel whenever there were big debates about endianness. Big won out because it's more natural, but there are still people who claim the other is better. I guess most systems and computers at this time used little.

low cost pcb

Edited: 06/29/2016 at 01:54 PM by LayneFelix

Jul 9, 2016 at 9:07:58 AM

Daniel_Doyce (0)

< Meka Chicken >

Posts: 683 - Joined: 04/22/2016

Ohio

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I'm about to go through these tutorials in detail. Are the source code files still hosted somewhere? I see references to code in each of the sections, but no attachments. Thanks!

-------------------------
Koeinalia: A Compendium of Koei Knowledge - NES and SNES

Jul 9, 2016 at 9:29:26 AM

SoleGooseProductions (129)

(Beau ) < King Solomon >

Posts: 3503 - Joined: 04/22/2013

Michigan

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Originally posted by: Daniel_Doyce

I'm about to go through these tutorials in detail. Are the source code files still hosted somewhere? I see references to code in each of the sections, but no attachments. Thanks!

In the last paragraph of each lesson there is a link (it says "click here", but it is part way into the text). They seem to still be good for me. Good luck with learning, ask as many questions as you want .

-------------------------
"The light that burns twice as bright burns half as long..." ~ Blade Runner

SoleGooseProductions.com

Jul 9, 2016 at 9:36:16 AM

Daniel_Doyce (0)

< Meka Chicken >

Posts: 683 - Joined: 04/22/2016

Ohio

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Originally posted by: SoleGooseProductions

Ah, now I feel stupid. Got it, thanks!

-------------------------
Koeinalia: A Compendium of Koei Knowledge - NES and SNES

Jul 9, 2016 at 9:37:15 AM

SoleGooseProductions (129)

(Beau ) < King Solomon >

Posts: 3503 - Joined: 04/22/2013

Michigan

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Never feel stupid! Judgment free zone here.

-------------------------
"The light that burns twice as bright burns half as long..." ~ Blade Runner

SoleGooseProductions.com

Jul 9, 2016 at 10:32:20 AM

KHAN Games (89)

(Kevin Hanley) < Master Higgins >

Posts: 8123 - Joined: 06/21/2007

Florida

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The power of NGD on a Unicorn protects you.

-------------------------

gauauu: look, we all paid $10K at some point in our lives for the privilege of hanging out with Kevin

Jul 9, 2016 at 11:09:38 AM

SoleGooseProductions (129)

(Beau ) < King Solomon >

Posts: 3503 - Joined: 04/22/2013

Michigan

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Is the safe word still 6502?

-------------------------
"The light that burns twice as bright burns half as long..." ~ Blade Runner

SoleGooseProductions.com

Nov 8, 2017 at 5:49:11 AM

siudym (0)

(Lucas Siudym) < Cherub >

Posts: 1 - Joined: 10/19/2008

Poland

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Hi,

I have a problem with background animation. Mapper is UNROM, so the animation is changing the tiles in VRAM (NameTable)

Unfortunately, the method is poor and takes a lot of NMI time. How do you animate background elements (change BGR tiles numbers in VRAM) to minimize the VBLANK time (NMI)?

The code that is used for the animation:
[code]
;------------------------------------
BGR_Anim: ;in the NMI loop

INC Anim_Timer ;timer
INC Anim_Timer
INC Anim_Timer
INC Anim_Timer

LDA Anim_Timer
CMP #$00
BCC skip1

LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE1_AddrLO
STA $2006
lda #$10 ;pattern table bgr tile1 nr.
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE2_AddrLO
STA $2006
lda #$11 ;pattern table bgr tile2 nr.
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE3_AddrLO
STA $2006
lda #$20 ;pattern table bgr tile3 nr.
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE4_AddrLO
STA $2006
lda #$21 ;pattern table bgr tile4 nr.
sta $2007
LDA #$00 ;reset screen
STA $2006
LDA #$00
STA $2006

skip1:

LDA Anim_Timer
CMP #$40
BCC skip2

LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE1_AddrLO
STA $2006
lda #$12
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE2_AddrLO
STA $2006
lda #$13
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE3_AddrLO
STA $2006
lda #$22
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE4_AddrLO
STA $2006
lda #$23
sta $2007
LDA #$00
STA $2006
LDA #$00
STA $2006

skip2:

LDA Anim_Timer
CMP #$80
BCC skip3

LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE1_AddrLO
STA $2006
lda #$14
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE2_AddrLO
STA $2006
lda #$15
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE3_AddrLO
STA $2006
lda #$24
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE4_AddrLO
STA $2006
lda #$25
sta $2007
LDA #$00
STA $2006
LDA #$00
STA $2006

skip3:

LDA Anim_Timer
CMP #$C0
BCC skip4

LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE1_AddrLO
STA $2006
lda #$12
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE2_AddrLO
STA $2006
lda #$13
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE3_AddrLO
STA $2006
lda #$22
sta $2007
LDA BGR_NT_TILE1_AddrHI
STA $2006
LDA BGR_NT_TILE4_AddrLO
STA $2006
lda #$23
sta $2007
LDA #$00
STA $2006
LDA #$00
STA $2006

skip4:
RTS
[/code]

Edited: 11/08/2017 at 05:54 AM by siudym

Nov 8, 2017 at 7:48:31 PM

Mega Mario Man (63)

(Tim ) < Ridley Wrangler >

Posts: 2743 - Joined: 02/13/2014

Nebraska

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Originally posted by: siudym

Hi,

I have a problem with background animation. Mapper is UNROM, so the animation is changing the tiles in VRAM (NameTable)

Unfortunately, the method is poor and takes a lot of NMI time. How do you animate background elements (change BGR tiles numbers in VRAM) to minimize the VBLANK time (NMI)?

Ask this in this thread: http://nintendoage.com/forum/mess...

Hopefully someone there can help. I can't really see an issue from what you have posted. I have changed upwards to 36 tiles at once in my game with no issues. I know that's cutting it pretty close to the time limit with that many tiles.

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Nov 9, 2017 at 3:41:34 AM

Broke Studio (1)

< Crack Trooper >

Posts: 140 - Joined: 06/02/2015

France

Profile

Originally posted by: siudym

Hi,

I have a problem with background animation. Mapper is UNROM, so the animation is changing the tiles in VRAM (NameTable)

Unfortunately, the method is poor and takes a lot of NMI time. How do you animate background elements (change BGR tiles numbers in VRAM) to minimize the VBLANK time (NMI)?

after branching on Anim_Timer, and executing the corresponding code, you don't skip the rest of the code.
You should do something like this :

lda Anim_Timer
; cmp#$00 ; not needed
beq anim1
cmp #$40
beq anim2
cmp #$80
beq anim3
cmp #$C0
beq anim4
jmp skipAnimation

anim1:
; anim 1 code here
jmp skipAnimation

anim2:
; anim 2 code here
jmp skipAnimation

anim3:
; anim 3 code here
jmp skipAnimation

anim4:
; anim 4 code here

skipAnimation:

Note that I'm using BEQ and not BCC to check Anim_Timer state and update only once the NT.

Also you can replace this :

LDA #$00
STA $2006
LDA #$00
STA $2006

by this :

LDA #$00
STA $2006
STA $2006

and this :

INC Anim_Timer ;timer
INC Anim_Timer
INC Anim_Timer
INC Anim_Timer

by this :

lda Anim_Timer
clc
adc #$04
sta Anim_Timer

to gain cycles and ROM bytes.

Hope it helps !

Edited: 11/09/2017 at 03:46 AM by Broke Studio