Multiplayer comlynx from Championship Rally

[Songbird]

Championship Rally supports 4 players via Comlynx. (Fun fact: we only tested two players during development since we didn't have the equipment to test all four players until after the game was already published!) After seeing the discussion in this thread, I looked through my archives and I think I found the C / asm code used in Champ Rally for comlynx init and ID assignment. Please see the attached file.

 

In the main loop, here is what is called:

// INSTALL IRQ FOR COMLYNX
	InitComLynx();
	EnableIRQ(4);

	ComLynxEmptyBuffer();

// ... some code

// COMLYNX
	uMode = DisplayComLynxScreen();

// ... some code

	if (uMode == 4)			// Comlynx / multi-player
	{
#asm
		lda #7
		jmp _LoadAndExecPrg
#endasm
	}

The variable "uNrCars" in comlynx.txt (this was *.h. but couldn't attach it as a *.h so changed to a *.txt) is specific to Champ Rally but obviously could be re-labeled to be "playerNumber" or whatever.

 

Note I have not tried compiling the Champ Rally code since 2000, and this would have used a really old tool set, so no guarantees on anything! But I hope this is helpful as a reference to jump start more multiplayer games on the Lynx.

 

Have fun!

comlynx.txt

Edited September 30, 2018 by Songbird

[+karri]

Thanks Carl.

 

By the way. I did take 4 Lynxes with me to work at that time. We used to have Wednesdays as company sauna and gaming nights. There were lots of people playing Championship Rally on 4 Lynxes all ComLynxed together. So the game was tested on 4 Lynxes.

[Turbo Laser Lynx]

Thanks for sharing, that's very nice of you! Going to have a look at this.

[LordKraken]

Ohh that's nice to share this piece of code! I've seen some other code around, in pure C, so since I own Alpine games, I only probably need a BLL cable to send the game to a second Lynx (while the first one will run the game from the SD card).

 

Would be nice to try!

[obschan]

Would you remember how you were managing the traffic in game; errors, flow control, etc. ?

I am investigating the different possibilities to have something fast and reliable enough.

I am currently using a very basic round robin, it's fast enough but very far from being reliable.

[sage]

On 1/24/2024 at 5:29 PM, obschan said:

Would you remember how you were managing the traffic in game; errors, flow control, etc. ?

I am investigating the different possibilities to have something fast and reliable enough.

I am currently using a very basic round robin, it's fast enough but very far from being reliable.

you want the modified redeye code?

[obschan]

19 hours ago, sage said:

you want the modified redeye code?

Yes, I will be happy to see if I can fit it.
It will for sure be more reliable than anything I will come up with.

Edited January 27 by obschan