potatohead's Blog - Slowly getting back into it!

RSS Bot · December 3, 2008

Despite the horrible times, I'm slowly gaining ground. We've whittled life down to the point where it's doable no matter what. As things wind to a close, short sale on the old house, medical, etc... my free time has slowly been coming up.

On the Propeller, I've made progress on KABOOM! Think I've got the driver issues worked out. Dammit, it was a PITA to build the display on the fly. Should have went for the frame buffer... Oh well. Learned a lot. I think that will all be acceptable this week, meaning I can start on game logic and code to a game pad for now. Eventually, it's gotta be paddle, but that's another minor league project that I need breadboard space I don't have to work out.

There is some talk of getting a 6502 core up and running. One COG just might be fast enough to hit the VCS speeds. So, I'm collecting docs and looking around at what's out there. Found a couple of them written in C, instead of x86 assembly. For some reason, I just have a hell of a time with x86. It's painful. The C ones look good, though. Makes for a nice start. One guy ran one through a filter, and left a rough SPIN translation on the net. Don't know if it works, but it's a start.

The plan is to load up an Atari style text display driver. Standard 40 char, 8x8 display, then run some simple 6502 code on both the Prop and my old 400. Found my copy of MAC / 65. I've no storage medium at the moment. (lost in move, with my original 7800 and VCS...) Ok for short benchmark, testing code though.

First pass will be my assembly "hello world" deal. That's counting numbers from 000000 to 999999 with a timer to see where the speed is at. I've done this on every platform that had a display capable of it, as my first step into assembly. Have all the pieces for that done on the prop, but for the CPU. Being on a little multi-processor is kind of cool. Basically, all that needs to happen is setup the display, fire off the CPU, and include the sample executable as a file to be compiled / assembled into the finished program image to be loaded. Easy stuff, from that perspective.

What I can't see yet is how to make one chip talk to another in this environment. I think it's gonna be about having each one output it's state, all looking at a master clock, and each reading what it needs to read, while the others are writing what they need to write. If so, that's a small block of shared memory for a BUS of sorts. If not, well... I'll need some help. Probably need some anyway.

Been looking at the 6502 from a different perspective because of this. It's a cool chip! (love the 6809 more, but it's not seen so wide of use...) I think I'm starting to understand an aspect of this era of computing that I didn't before. Looked at the TIA too. Same kind of coolness. I've a lot of admiration for those people who went the distance, grokked the schematics, and got their emulators up and running. I've got a lot more for those people able to build from that kind of environment too. Today, there is a lot of patch work, lego style development. The designers of these older chips just flat knew their shit, and got it done the hard way, with a drafting board, state diagrams and such. Kick ass.. I've got some schematics printed E size to look at. I know more about them now, and that makes them worth hanging up in the office.

Maybe someday we can get a 4K 2600 game up on the thing...

Pulled the 400 out and my newer plasma TV will display it. Sweet! I dimmed the lights, cranked the contrast on the thing, and played for an hour or so. Freaking love that game. Always will.

That's about it. I've got a reason to pull the 400 out now. It's getting a bit senile, as some games will fail after 30 minutes of play. Probably bad caps or something. (Star Raiders always seems to work though.) That is the last original bit of hardware from when I was a kid. Well, that and the supercharger. It's gonna be craigs list, or here for some purchases next year. Hate not having a VCS. Emulators are ok, but there is just something cool about firing up the actual unit for some simple game action.

(and It's killing me not to play Medival Mayhem! That's probably the best purchase I've made for the VCS. Homebrew rules. That is the work I show off right now to the unbelievers. Most of them are sold after an hour or so of game play.)

Projects then are continuing to work on KABOOM!, and starting on the 6052 core. There are a few people interested in seeing that go, so it's not a solo thing.

http://www.atariage.com/forums/index.php?a...;showentry=5541