Can anyone tell me what I'm doing wrong

[atari_aaron]

I'm currently trying to work my way through "Nick Bensema's playfield primer" for the 2600... but when I try to run my assembled code through Stella all I get is a blank screen.

 

One problem I see... and I'm not sure if it's a typo in the primer:

 

Primer Reads - cut and past from HTML document:

 

; Clear all registers here to prevent any possible bleeding.

;

LDA #2

STA WSYNC ;Finish this scanline.

STA VBLANK ; Make TIA output invisible,

; Now we need to worry about it bleeding when we turn

; the TIA output back on.

; Y is still zero.

STY PF0

STY PF1

STY PF1 <---Notice repeated line - I wrote "STY PF2" instead

STY GRP0

STY GRP1

STY ENAM0

STY ENAM1

STY ENABL

RTS

 

Should I have left it as "STY PF1"?

 

The bin file I assembled, the code as I copied it into a txt file, and the vcs.h file I am using can all be found at the following URL:

[url="http://testserv.archaeology.ndsu.nodak.edu/~abergstr/atari/"]http://testserv.archaeology.ndsu.nodak.edu...gstr/atari/[/url]

 

I don't understand it... the thing assembles using dasm, but all I get is a black screen when I run the bin in stella. I realize the problem is my fault, but I can't seem to find my mistake.

 

Any help would be appreciated.

 

Thanks,

 

Aaron

[DEBRO]

Are you using the -f3 option for DASM? You should assemble your code using <filename> -f3 -o<filename>.bin

[Thomas Jentzsch]

Should I have left it as "STY PF1"?

No that's an old typo. STY PF2 is correct.

[atari_aaron]

Yes, I am using the -f3 and -o options.

[+kisrael]

Don't know exactly how to diagnose your problem...but you might want to consider following the "development environment" page of my 2600 tutorial at

http://alienbill.com/vgames/guide/

see if you can assemble Chris Cracknell's digital clock

[atari_aaron]

Well... I got it to work... I tried 5 things at once... and one of them worked anyway... Can't say that the result was very pleasing to the eye. I think I wasn't turning on the VBlank... I think I was trying to turn on "VSYNC" oops... Anyway, something good came out of it... I think I finally understand the basic graphics concepts behind the TIA.

 

In an odd sort of way, I like how it works... 60fps... no if's, and's, or but's... I'm use to the java3d way of doing things... that is "oops, 0.4 fps... I guess I have too many polygons".

 

I actually have gotten my own playfield to draw... but it's increadibly crappy... besides just repeating itself with no regard to stopping or starting at the top or bottom of the screen... it's doing this annoying flicker thing.

 

I guess I need some scanline discipline... I've got time to work on it... I'm going to India tomorrow morning for two weeks... nothing like being in the air on and off for 24hrs (both ways) to help you think about things... nothing else to do really. At least I'll have a laptop... might comeback with something to show... wouldn't that be nice.

 

Thanks for the suggestions everyone,

 

Aaron

[Cupcakus]

There is no way to program the 2600 without the stella programmers guide... GET IT! :-)

 

When I decided the only way to get my program to work the way I wanted was an ASymetrical Reflected playfield I for the life of me could not get it going... It's a super tight kernel but the Stella Programmers guide got me through it

[atari_aaron]

Check it out... long plane rides actually are good for the soul... I've completed an assymetrical playfield radar map for my game. The code is rather simplistic, but it works.

 

http://myweb.cableone.net/bergstrom/ebkc135/

 

You can find the bin for the radar map and screenshots.

 

Thanks,

 

Aaron

[calamari]

Nice radar map. Your programming environment is also cool.

 

calamari

[atari_aaron]

Thanks for the compliment... I'll keep everyone posted on the programming environment. Now it's back to work and school related stuff... probably until after Christmas. Though I'll probably do some more work on CAG befor then. I've got more research to do on scrolling playfields before I do more work on EB KC-135.

 

Aaron