Stacy,

You are correct when saying it has something wrong with the internal architecture of the 16F648a microcontrollers, infact any 16F microcontroller.

I think it has something to do with the limited call stack, The key thing to understand about the 8 bit PIC architecture is that the stack size is fixed and the 16f648a has a stack size of 8.

If the 8x8 game system used a 18F series microcontroller with a call stack of 31 then I dont think there will be much of a problem other than the time it will take to programme all the games onto the 18F microcontroller.


Heres all ive got to run on the 16f648a, Brads version of the bouncing balls and the race car game, with some personal changes eg added 3 lives to the race car game and I use the bouncing balls has a sorta screen saver?.

can you fit all the 8x8 game system games into a 18f

Thanks for the info Chuck but the 8 level call stack is not the problem. I have gone through the code and replaced most of the CALL directives with GOTO directives (where they could be replaced). When I run the program on the simulator I watch the call stack and have managed to keep everything under 8 levels. Of course I have also replaced any of the applicable RETURN's to GOTO's as well so the program will return correctly.

I had originally found a problem with the way Brad accesses the table data and have fixed that (it was jumping page boundaries) but that only solved one of the problems I was having. Again, everything runs great in the simulator, just not in the circuit.

In the video below, I did not explain it very well, but I can get either game to work correctly, just not both.



Stacy

Hey Stacy nice video, I was under the impression that you was adding all of Brads 8x8 games to the microchip, that what lead me to think that the problem could be with the call stack?, with two games or so that should'nt be a problem?.

Just so I can understand your problem abit more, Do the race track game work ok the first time you turn the power on and if you start the race track game first?

if you would like me to I could try your code on my system and test the results?



ps. have you been playing too many games with your thumb bandage? Or is that from trying to sort this problem out!!

Really like the video Stacy!

I remember you working on getting multiples games working on the one chip and all of our conversations about page boundaries and data tables - fun times

Sorry for skipping out on the conversation guys but I got really busy at work and haven't had the opportunity to chat much on the forum.

I also started a project that was supposed to take only a few hours over the weekend but somehow ended up taking up the majority of the weekend and I still didn't finish.

I was hoping to show you the finished product but it will have to wait. For now here is a sneak peek...




@ Bitfogav,

I had started my program by adding all of the games on the chip but when I could not get the games to work correctly, I narrowed it down to just two games. I still could not get two games to work correctly. As I mentioned before, when Brad decided to move to the SPB, I moved on to other projects. From time to time, when a new idea pops in my head, I will pull out the program and try it.

Thanks for the offer to debug it on your circuit and I might take you up on it some time. I actually have several different versions of the program that I started because I was trying to figure out the best way to implement the algorithm (I love that word). I will need to go through the programs and find the one which would be least confusing to explain!

By the way, the bandage is simply to cover up a nasty black area under my thumbnail where I smashed it in a car door.


@ Brad,

Yes I remember the good ole' days of page boundaries and data tables. You should come back to the dark side young Jedi.


Stacy

What is that crazy thing? a doomsday device? A flux capacitor?

Well anytime Stacy just give me a shout when your ready!!

No silly, it's an edge-lit acrylic sign I am going to hang above the entrance to my lab at work!

Finished...







Stacy

PS> Forgive me for hijacking the thread... now back to the programming topic!

You are the thread hijacker!

By the way, nice sign!