38 replies to this topic

[pr0be]

Hello

I need to test my multiplexer engine on REAL NTSC machine, unfortunately i don't have one...

Can somebody test this thing on real NTSC atari?

on Atari800Win in NTSC mode seem to work fine, but to be honest i don't trust emulators too much

Attached Files

•  c_test.zip   6.83K   253 downloads

[atariksi]

pr0be, on Wed Sep 30, 2009 5:51 AM, said:

Hello

I need to test my multiplexer engine on REAL NTSC machine, unfortunately i don't have one...

Can somebody test this thing on real NTSC atari?

on Atari800Win in NTSC mode seem to work fine, but to be honest i don't trust emulators too much

It works on my 800XL (NTSC), but it doesn't scroll left (if it's suppose to). I was able to shoot a few of the enemies and jump and scroll right. But you need to post a screen shot and description so anyone who tries it can compare with it.

[Fres]

Works fine on my XEGS. Looks like a promising project. Is that Contra? Great playability so far!

[MrFish]

Nice "test"

[Synthpopalooza]

MrFish, on Wed Sep 30, 2009 6:03 PM, said:

Nice "test"

Indeed. How does this sprite multiplexing engine work? Very impressive.

[Heaven/TQA]

Cool stuff! looks like a Contra port on the way? or only a test?

[dwhyte]

Bloody brilliant "test!" Excellent work! Well done, sir.

Edited by dwhyte, Thu Oct 1, 2009 12:36 AM.

[Shannon]

Wowzers!!

[Allan]

I must be have been dreaming because I think I just played Contra on my Atari and that can't be possible.

Allan

[pr0be]

atariksi, on Wed Sep 30, 2009 8:23 AM, said:

It works on my 800XL (NTSC), but it doesn't scroll left (if it's suppose to). I was able to shoot a few of the enemies and jump and scroll right. But you need to post a screen shot and description so anyone who tries it can compare with it.

if you didn't notice any artifacts or sprite distortion like spliting sprite into two parts (one or more lines of the same sprite are in different X position) that it seems to work fine...

Thanks for help!

Synthpopalooza, on Wed Sep 30, 2009 10:57 PM, said:

Indeed. How does this sprite multiplexing engine work? Very impressive.

basically it's sorts all sprites by their Y-position, then starts from the top to bottom drawing each sprites from sorted list to PMG0-1 (if its free on current charline), if PMG0-1 is already used in current charline, the multiplexer try to draw this sprite to PMG2-3, if both PMG0-1 and PMG2-3 are not free then multiplexer try to figure out which sprite reject in next frame and which sprite to draw (it use priorities to determine sprite rejection)

I was worried that NTSC machine can have problem to change six registers in one scanline, but it's seems to work fine...

Heaven/TQA, on Wed Sep 30, 2009 11:16 PM, said:

Cool stuff! looks like a Contra port on the way? or only a test?

it's another test , but I'm very close to finish "universal" 2d game engine, so after that making a 2d game should be very easy
today i started ripping graphics from super mario bros to see how it would look... maybe tommorow I finish it and share results...

[analmux]

@ Pr0be : Don't worry about number of cycles in one scanline : There are 114 (minus refresh & gfx dma) cycles on both PAL / NTSC machines. Also the # of refresh / gfx dma cycles stolen is the same on both video systems.

The bigger problem is the number of scanlines in one frame. On NTSC the vblank period is much shorter, so take care of the sorting routine. It should finish before end of vblank period, or at least before the first sprite is drawn.

Anyway, nice project! Good job. Good luck finishing it.

[Heaven/TQA]

Cze Probe.

Any chance for releasing the source code after your test? if so... please make the source easy to read or at least some comments...

[pr0be]

analmux, on Thu Oct 1, 2009 2:38 PM, said:

The bigger problem is the number of scanlines in one frame. On NTSC the vblank period is much shorter, so take care of the sorting routine. It should finish before end of vblank period, or at least before the first sprite is drawn.

I notice that... on PAL my multiplexer can display about 18-20 10x16 multicolored sprites in one frame, on NTSC only 13-14... pretty much different

Heaven/TQA, on Thu Oct 1, 2009 11:26 PM, said:

Any chance for releasing the source code after your test? if so... please make the source easy to read or at least some comments...

I have plan to release this engine as linked library with full documentation and some examples that using it.


Another quick test, this time Super Mario Bros...

Attached Files

•  smb_test.zip   5.01K   127 downloads

[Tezz]

Just for fun and as I've had some free time.. see attached just incase Contra ever becomes a project that someone wants to take on.

Attached Thumbnails

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Attached Files

•  contra.zip   3.57K   102 downloads

[Tezz]

pr0be, on Sat Oct 3, 2009 6:43 AM, said:

I have plan to release this engine as linked library with full documentation and some examples that using it.

It's excellent, and good news. I'll look forward to that.

Do you have any plans to create complete games personally with your engine?

[pr0be]

that Contra title screen looks great, nice mixing hires with pmg.

I'm only considering possibilities to make conversion of Contra/Super Mario Bros/other games by checking how game would look on Atari... it's small chance that I port any of this games - I would rather make exclusive title...

Tezz, on Sat Oct 3, 2009 7:42 AM, said:

Do you have any plans to create complete games personally with your engine?

Yep... We (Me, Born and Powrooz) started a new game project some days ago... but it's too soon to say some details... It will be platform shooter for sure

[Tezz]

pr0be, on Sat Oct 3, 2009 8:18 AM, said:

Yep... We (Me, Born and Powrooz) started a new game project some days ago... but it's too soon to say some details... It will be platform shooter for sure

awesome. That's great news!

[Jetboot Jack]

A couple of really nice demo's of your techniques - very intriguing, can't wait to see what you decide to make!!

sTeVE

[w1k]

very very nice..

[analmux]

pr0be, on Sat Oct 3, 2009 6:43 AM, said:

analmux, on Thu Oct 1, 2009 2:38 PM, said:

The bigger problem is the number of scanlines in one frame. On NTSC the vblank period is much shorter, so take care of the sorting routine. It should finish before end of vblank period, or at least before the first sprite is drawn.

I notice that... on PAL my multiplexer can display about 18-20 10x16 multicolored sprites in one frame, on NTSC only 13-14... pretty much different

Heaven/TQA, on Thu Oct 1, 2009 11:26 PM, said:

Any chance for releasing the source code after your test? if so... please make the source easy to read or at least some comments...

I have plan to release this engine as linked library with full documentation and some examples that using it.


Another quick test, this time Super Mario Bros...

Interesting...could you roughly say how much CPU time the object sorter and the data stuffer individually take.

I'm curious if such a PM solution would be possible for the SMB-port I'm thinking of (See elsewhere on the forum).

[pr0be]

analmux, on Sat Oct 3, 2009 1:53 PM, said:

Interesting...could you roughly say how much CPU time the object sorter and the data stuffer individually take.

I'm curious if such a PM solution would be possible for the SMB-port I'm thinking of (See elsewhere on the forum).

blue rasterbar - clearing pmg area
green rasterbar - drawing sprites and updating displaylist
red rasterbar - sorter

I use insertion sort for sort sprites - I think that is the fastes algorithm to sort small amount of data (radix sort is better if we have more than 16 sprites to sort)


I looked into disassembled SMB source code (smbdis.asm) and i have felling that it would be easier to write all code from scratch that modifing and analyzing orginal source code (Yep it is well commented but i don't think that i would have patient to do it

it's quite impressive that you manage to run nes code on atari, i don't know exactly how nes handles a sprites but i suppose that very similar that my multiplexer so i think that sprites is not a problem... more difficult would be changing engine to use LMS feature to scroll screen

Attached Files

•  mp_test.zip   5.3K   107 downloads

[pr0be]

I also attach smb_test with rasterbars test to see how much CPU time is consuming...

Attached Thumbnails

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Attached Files

•  smb_test2.zip   5.03K   122 downloads

[Allas]

Good work!!

I need one of those routines

[matosimi]

Simply incredible!

[Reaperman]

this is simply incredible. great work pr0be.
I'd love to see how all this turns out.