DaveM

Update - So I stepped away from the project for a few days to let my mind clear, then went back and looked at my notes and re-read parts of the book, and realized that my kernel was, well, not that good. Far too many cycles. So I took a shot at re-writing the kernel and changing a few other parts of the code. I had some calculations in there which vertically flipped the player 0 bitmap, but that was taking up far too many cycles. So I removed that in favor of adding extra bitmaps for the animation. To make room for that, I removed one of my arrays, and moved that data inside my playfield graphics array, so parts of the playfield now serve multiple purposes. Along the way, I realized that the PF0 and PF1 registers will always be the same, so no need for extra data for both, and no need to load two values - I just load the one value and write it out twice. I re-worked some of my other calculations, trying to minimize them the best I could. I almost made it to the proper number of scanlines, but not quite. However, I now can get the Yo-Yo and the playfield on screen, but only by displaying them on alternating frames. This causes significant flicker on the 8-bit workshop tool, but doesn't look too bad when I run the compiled ROM through Stella. I've attached the code and ROM of what I have so far. Any suggestions on anything further I can do to save some cycles inside my kernel so I won't have to alternate frames? Thanks in advance! mr_yo_yo 0.3.a _mr_yo_yo.0.3.bin

My original first post starts below this link. If you're looking for the most-recent release of the game, you'll find it here: Original Post: Hi everyone. I'm starting work on my first homebrew, and running into some issues, so I'm hoping someone here could assist. I did a number of hacks quite a few years ago, I think "Fat Albert" is the most well-known, but I got away from doing those and I'm just now diving back in to try to learn how to make my own game. I've programmed VB/VBA/.Net for quite a few years, and have done some games in those languages, but I've never learned any sort of assembly language. I purchased Steven Hugg's book, and got about 2/3 of the way through it before my brain fried. I thought then I'd get a start on writing the game using what I learned up to that point, then get back to the book later on. So a little about my game idea, then I'll describe the problems I'm having. I had an idea to create a game where the button controlled the movement, and the joystick controlled the firing mechanism, basically the opposite of what most Atari games are. So the idea is that you control a Yo-Yo. You push the button, and the yo-yo moves down. Release the button, and he zips back up his string. Push the joystick right and left, and he'll fire his laser gun right and left. The object will be to descend all the way to the bottom of the screen, pick up an object, and bring it to the top of the screen. Repeat this a certain number of times to clear the level. Meanwhile, enemies will enter from the sides, moving horizontally (similar to Turmoil). Some enemies will only hurt you if they hit the yo-yo itself, while others will cut your string if they pass above you, requiring you to zip back up to either blast them or get above them before they reach your string. Occasionally bonus objects may fly in from the sides that you can collect for points or power-ups. That's the basics of it. Sort of a cross between Turmoil and Freeway. So far, I'm able to get Mr. Yo-Yo to move down and up when you press/release the button, and I got his animation to work so he spins clockwise on the way down, and counter-clockwise on the way up. He continues to spin if held down at the bottom of his string, and stops spinning when he reaches the top. I also got the string to draw above the yo-yo. All of that is the Player 0 object. All that works fine. The problem comes in when I try to add anything else. I tried adding the playfield, and the screen started flipping. So early in the design of the game, and I'm already blowing way past the 262 scanlines. I've been staring at the code for hours now, trying to figure out ways to condense things, and I'm just not experienced enough yet to figure that out. I'm hoping there's a more experienced programmer here who would take a look at my code (attached), and see where I can save a few scanlines here and there, or maybe see where I'm doing something totally wrong that could be done much more efficiently. I'm not looking for someone to write the game for me, but I've been banging my head against the wall long enough and need some help to push me in the right direction. And when and if I get the game finished, I'll be more than happy to share it with everyone here. Thanks! mr_yo_yo 0.2.1.a

Well, I guess this is as good a time as any to finally jump into this message board... Glad to see you all liked the game! The graphics were pretty much just plucked from the cartoon. I found some images on the net, resized them a bit, printed them out on some graph paper, and went to work on it. I just wish I could've done better with the head you control during the game itself, but there's only so much you can do with an image that's only 8 pixels wide. Anyway, thanks again for the compliments!