AtariAge Forums: Propane13 - Viewing Profile

http://www.retroist....tari-2600-games

Ok peeps-- why haven't I heard about this?
(anxiously awaiting someone to point him to the main thread about this).

(sorry if this the wrong forum too-- but I see "Super Breakout" which generally means 2600 (unless there was an arcade game of that same name). Plus the art seems 2600-ish.

-John

Hi!

I am interested in putting some Driving Controller support into a game I'm writing.
But, I don't have much info on how they work.

Here's the only thing I could find:
http://videogames.or...vingControllers

It's an old email, that I guess you have to open in Wordpad, and it seems to be missing some info,

What I'm gathering is that the 2 nibbles of SWCHA are impacted.
The left 4 bits are impacted if the driving controller is plugged into port 1.
And the right 4 bits are impacted if the driving controller is plugged into port 2.

It sounds like from the article that the bits are impacted as such:

Rotating left
1100
1101<--|
1111 |
1110 |
1100----
...
etc

Rotating right
1100
1110<--|
1111 |
1101 |
1100----
...
etc

This is good, but it brings up some questions:

1) If I wanted to "auto-detect" a Driving controller, I'm guessing I could just poll SWCHA each frame. I would assume the user was using a joystick until I came across 1100 in SWCHA's left nibble, which is a "Joystick Impossibility", and if this occurred, I could jump to driving controller mode, correct? I am worried of a potential con where there is noise on the controller lines, and by accident, we get 1100, and then are stuck in driving controller mode, when we really have a joystick plugged in. How high is the probability of something like this happening?

2) How often do these values get updated in the hardware? I am guessing it's instantaneous.
If that's the case, how do you get around this situation:
a) Start of frame 1: driving controller in %1100 position
b) Middle of frame 1: user spins driving controller left "really fast". It cycles through 3 states-- from 1101 to 1111 to 1110
c) start of frame 2: driving controller is in 1110 position
d) Character on-screen moves right instead of left (oops)
My guess is is that there's a "number of times per frame" these need to be checked, and that corresponds to the fastest that someone can spin the knob. Does anyone know what that number is?

Thanks!
-John

Let's start with a teaser mockup.

 mockup.gif (5.9K)
Number of downloads: 122

-John

Does anyone know where I can find a picture with all of the Pitfall sprites (and perhaps Pitfall II)?
I'm not sure if this exists, but I'm guessing that it does.

At a minimum, I'm interested in analyzing Harry's Running animation.

Thanks!
-John

So, while scrounging on my old Tower computer, I found some files that may be of interest to the community.
I was doing some 7800 programming back in the day. I'd like to share my journey from 2001 to 2003.

First, we have the "Hello World" demo. Honestly, I think this was someone else's code, just my verification that I can compile it. Maybe I added a word in it or something, but it's pretty lame. No credit for me on this one.
 Converted_20010525_hello_world.gif (1.48K)
Number of downloads: 51
 20010525_hello_world.a78 (48.13K)
Number of downloads: 51

Next, we have a color demo. At the time, remember, emulator support was very, very low (MESS, which did not run well on my slow computer), and there were no cuttle carts. So, I did EPROM burning tests a lot. So, I made a "color cart" as a permanent addition to my cartridges. Here it is:
 Converted_20010804_color01.gif (1.79K)
Number of downloads: 45
 20010804_color01.a78 (32.13K)
Number of downloads: 48

After that, I decided it was time to make a game.
I wanted to write a zelda-like game. Here it is:
 Converted_20020623_zelda_1.gif (5.8K)
Number of downloads: 56
 Converted_20020623_zelda_2.gif (6.04K)
Number of downloads: 52
 20020623_zelda.a78 (32.13K)
Number of downloads: 61

It was during this stage that "Mister Purple Pants" was born.
I liked the demo, but I ran out of graphics space. My general thought was that I wanted to see the limit of overlapping sprites. Apparently, it hit me too fast before I could do other interesting things, so I had to abandon that kernel in favor of another one.

So, this brings me to one of my more favorite demos.
 Converted_20020721_falling_demo.gif (4.71K)
Number of downloads: 64
 20020721_falling_demo.a78 (32.13K)
Number of downloads: 62

I thought I needed to learn about graphics compression techniques. So, I did.
I learned how Mega Man did its graphics, as well as Metroid. I put "Mister Purple Pants" in a one-room world where there was constant gravity. He can jump from item to item, so this is just a demo, but it seemed to be going in the right direction.

But, it was then that I wanted to try another project. I was thinking "What is the one game that the 7800 doesn't have that it really should?" The answer was Frogger.
 Converted_20030101_frogger_nosound.gif (3.45K)
Number of downloads: 47
 20030101_frogger_nosound.a78 (32.13K)
Number of downloads: 51

Writing this frogger demo got me excited (it could have gone somewhere), bit I also got really, really bored after writing this one screen. I thought it was a great demo, but I had so many things to worry about at this stage. Do I be arcade-perfect? If so, will that bore me, or would I rather do my own game? How will I deal with all of the collision detection? These questions haunted me for some time, and I decided to abandon the work done so far, and go back to Mister Purple Pants.

And, here is Mister Purple Pants in his last appearance.
 Converted_20030728_purplepants_1.gif (6K)
Number of downloads: 50
 Converted_20030728_purplepants_2.gif (6.07K)
Number of downloads: 48
 20030728_purplepants.a78 (32.13K)
Number of downloads: 57
This is what I ideally would have turned into a Mega Man style game. Scrolling is complete, and there's a few screens worth of world defined. I was quite happy with it. But, then, real life got in the way.

There wasn't a lot of knowledge or tools for the 7800 back then, so I typically found myself striving to get one demo done at a time. And, with this final demo, I gave up. Now, it's neat to see that the community has gotten through some of the major issues that were headaches for me back in the day.

I was really, really secretive about these in the past. I really wanted to drum up excitement about releasing a 7800 game, since none were created for a very long time. But, now that I look at it, these things are probably better shared with everyone. Maybe they'll be of interest.

Best regards,
-John