[untessed controller code. feedback appreciated]

<edited previous post>

[untessed controller code. feedback appreciated]

So been working on a project and wanted some feedback on what I came up with. Just wanting second opinions if my logic is sound. This gives controller directions and debounce data. it could also be expanded to include any action buttons if single player or all cardinal directions for 2 players. Call either once per frame or just between usage of control inputs.

 

	;		1 = off		0 = on


	;previous poll		active poll							debounce

	;	1		1	and 1 then answer xor previous 0 then invert		1

	;	1		0	and 0 then answer xor previous 1 then invert		0

	;	0		0	and 0 then answer xor previous 0 then invert		1

	;	0		1	and 0 then answer xor previous 0 then invert		1


	; ram variables for controls

	; current_poll

	; debounce

	; temp_1





control_check/reset

	; uses inverted logic 1=off 0=on

	lda SWCHA

	and #$F0	;keep only player 0 data. omit if using both players

	sta temp_1

	and current_poll

	eor current_poll

	eor #$FF

	sta debounce

	lda temp_1

	sta current_poll

	; for the rest of the game code check the debounce for trigger activation of any direction

	; or check current poll for continued activation of any direction

	rts

 

[Sleeping with Optimal Efficiently]

Crazy idea. Maybe you could use a pre existing loop system like horizontal positioning with an extra branch at the end for a special case for the delay. Just set an object you won't use and branch out on it. Just a thought

[Sleeping with Optimal Efficiently]

Something I like to use is the last part of this guide. You can achieve more than listed by using combinations while keeping the rom footprint low.

https://www.qotile.net/minidig/docs/2600_advanced_prog_guide.txt

Anything more would require a loop

[random brainstorming what if code]

Just had a little thought about something and wondered if anyone has done this before or if it would ever be useful at all. so with standard subroutines they are absolute but with jumps they are either absolute or variable (indirect) so with some extra code we should be able to have indirect subroutines. I sudo coded a brief example of what I mean and wondered if it had any merit. My syntax may have errors but  hopefully the idea gets across.

 

	Indirect_Subroutine = $80	

	I_S = $81

	;some code


	lda <#subroutine_B

	sta Indirect_Subroutine

	lda >#subroutine_B

	sta Indirect_Subroutine+1


	; some more code


	
	lda <#continue_from_routine

	pha

	lda >#continue_from_routine

	pha

	jmp (Indirect_Subroutine)

continue_from_routine


	;some more code



subroutine_A

	;do stuff

	rts

subroutine_B

	;do_stuff

	rts

subroutine_C

	;do_stuff

	rts

 

[Representing the Atari 2600 and 6502/6507 programing]

Here are a few other pics of the event and the tv in the background playing Galagon.

[Representing the Atari 2600 and 6502/6507 programing]

Hello all, it's been some time since I've posted on the forums. But now I have a cool story (at lest i find it cool) I wanted to share with everyone here. 

 

    I recently attended a top secret annual conference meet up in Chicago (my first time visiting the city) known as Thotcon. This conference lasted 2 days and is a meet up for network security workers and generally anyone in IT, tinkerers or white hat hackers. There were many talks and seminars on various computer and networking subjects as well as other activities.  I was invited by my good friend whom we will refer as Mr. E to participate in what they call a "village". This particular village (one of several) I had suggested the name ASMb1337 because my buddy wanted me to expose modern coders to the old ways and help get their feet wet with some old school coding. We have a website  www.hacknwa.org which simply links to the required resources to code 6502 assembly that attendees could download and try out. For the event Mr. E  had me code a simple 4k demo scene with some music to show off our groups local logo that moves on screen. The source code was available to attendees and their goal was to modify the code, recompile and be a stable build to win a prize. The prize was a blank NES cart dev board that they could use to experiment further with 6502 but this time for the NES. It was a ton of fun and I would love to do it again. That said, there was one thing I had wished to do with the demo that I never finished with. Although it works fine as is, I had wanted to implement a sort of parabolic motion to the logo so as it would slow down before reversing direction and speed up when in the middle of the screen. I wondered  if anyone here wouldn't mind to take up the task to implement this feature. My coding is mediocre at best and I'm not near as seasoned as many here so I know the code looks weak but it works. So here are a few pics including my good friend who got me involved and a few for the event. The source and 2 different builds to do something different. Credits go to Paul Slocum for his wonderful music engine and web based tracker. Music is credited to another good friend of mine who goes by the handle The Thunder Lizzard. included the music and song player headers.

hacknwa.asm hacknwa.bin hackNWA2.bin song.h songplay.h

[Will DASM do this for me?]

7 hours ago, SpiceWare said:

 

That's what I did for the RPG Bus Stuffing demo, the tiles are defined with colors interlaced with graphics:

 

 

 

At least this makes the manual method a little easier. Just had hoped there could be an ORG/RORG EVEN/ODD feature

[Will DASM do this for me?]

I need to place 2 tables of bytes (graphical data) in rom. However, i need one loaded in even addresses and the other in odd addresses. I would like to avoid manually interlacing my graphical data as well as color palettes. People keep saying let DASM do it for you so was wondering if it was up to the task.  

[Indirect index pointer offset]

Slight dilemma. If I'm using an indirect pointer with the Y index and I need to offset the pointer because the Y index isn't inline with the true pointer, then does the page value just wrap itself to do this or does the high byte need to be adjusted too. Technically, no page boundary  access would occur. 

Ex: data to be accessed is located on any arbitrary page of the 4k rom space starting at 00 to say 0B. This is 12 bytes worth. Likewise, the pointer in ram would have 00 be the start (or end) with whatever page the hi byte is as the 2 byte pointer. Providing the y index is exclusively set to index this data, everything would work as normal.

However, if the Y index is decrementing from 30,  then the pointer would need to be offset before hand so that the data reads correctly. It would stop before going below the pages 00 address so as not to access data across a page boundary.  So does the 2 byte pointer only need the low byte changed or both the high byte and low to compensate this? Sorry if the explanation is overly complicated. I don't want to incurr any extra cycles.

[DPC+ over 32K?]

I would be more interested in 64K with DPC+ only. no Bb. 

[6502 Instruction Set Guide - printed booklet]

Got mine.

[New Homebrew - Kick Ice]

On 11/4/2021 at 10:21 PM, DaveM said:

Things are going MUCH slower than I had hoped.  Just not enough time right now to devote to working on the game.  BUT... progress is being made!

Baby Yoda? Or rather Grogu.

[6 digit score]

here is my two bits for what its worth. I'm very visual when it comes to kernel coding and I have to draw out my code visually to the screen alignment. This seems to almost always get cycle exact code as long as it doesn't cross any page boundaries. It may not make much sense to some people, but it works for me. Just thought I would share this version. It only runs absolute addressing for a 48 pixel static image but also allows PF1 to get loaded too for the first copy and blanked for the second copy. 

[Software Speech Synthesizer for the 2600]

Awesome the possibilities are near endless.

[Beyond Castlevania...]

On 8/7/2020 at 1:52 AM, tokumaru said:

It just occurred to me that Atari 2600 graphics drawn exclusively with playfield pixels look a lot like SNES graphics... in mosaic mode! It kinda looks like the game is in the middle of a scene transition (à la Super Mario World), and my brain keeps waiting for the animation to finish and the final graphics to appear.

 

Not that the graphics look bad or anything, it's just that rendering detailed backgrounds is far from being one of the things the 2600 excels at. I love all the mock-ups posted in this thread, especially because they're so unconventional.

 

[Taxi Panic!]

I would like to see 00page homebrew play this one.

[Best way to mirror a byte?]

Here is one using tables

 may run faster

byte mirror flip.txt

[Beyond Castlevania...]

[Beyond Castlevania...]

22 hours ago, Propane13 said:

(Wakes from his slumber).

 

Well, that was certainly a trip down memory lane.  Thanks for sharing!

 

-John

 

It sure has been a while for me too. 

[Tolerable flicker]

On 6/26/2019 at 10:06 PM, Omegamatrix said:

Are the pieces moving or static? I think 30Hz flicker will be okay. If you have a black screen keep the luminance low to make it more tolerable.

The pieces would be static and the screen would function more like a segmented LCD screen.

[Tolerable flicker]

As bad as this example looks Its only a gif. Stella blends well and a 2600 through a crt looks best. 

[Tolerable flicker]

Had some partial kernel code for several years for a puzzle games inspired by a rather popular casual game. I had worked out most of the general rules and kernel rendering but that's it so far. Recently crafted an animated gif to roughly demonstrate.

[Champ Games - Galagon (aka Galaga) 2600]

Does anyone notice if the big dipper and Orion are in the starfield like the arcade? I've tried and thought I saw the dipper once.

[Beyond Castlevania...]

Just gonna put this here for now...