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project:atari_asteroids_autoplay [2013/03/13 20:33] – smark | project:atari_asteroids_autoplay [2013/03/17 04:38] – [3/16/2013 @ 9:07pm] smark | ||
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- | I have also created a local copy (don't kill me Jed!) simply because I know a lot of these times of sites phase in and out of existence. I would hate for all of this great data to disappear. You can find the local copy {{: | + | I have also created a local copy (don't kill me Jed!) simply because I know a lot of these times of sites phase in and out of existence. I would hate for all of this great information |
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+ | Basically I believe I need to intercept the outputs of XVLD, YVLD, and BVLD. This is where all of the digital signals are condensed into the X, Y, and On/Off digital stream. From here it goes to the DACs which convert it to output to the Electrohome. I hooked an oscilloscope up to one of the leads of one of the LS134(?) chips which I think is XVLD or YVLD. Using the test pattern (which keeps the picture static) I was able to get a good look at the signal going through there. It looks like how I think a digital signal would look on an analog oscillocope... Lines at 0 and Lines at positive whatever voltage with no connections in between. Almost like _-_-_-_-_ or something. | ||
+ | ==== 3/16/2013 @ 9:07pm ==== | ||
+ | So I haven' | ||
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+ | I'm currently going around and around unable to decide where the best place is to intercept the data. I've found out where I can intercept it but it takes 8+ leads to get anything valuable out of it. XVLD/YVLD turned out to be a dead end as all they do are tell whether or not there is a valid value there. I'm torn in a few different directions...\\ | ||
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+ | Get the outputs from DACX1-10* / DACY1-10* / BLVD. The X/Y ends up being 10 bit values which are fed to the actual DACs (B11/D11). I hooked the logic analyzer up to B11 pins 13 thru 6 (DACY10-3*) where Pin 13 (DACY10*) is the most significant bit (512). It can be visualized as follows: | ||
+ | ^ DACY#* | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | | ||
+ | ^ B11 Pin | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | | ||
+ | ^ Sample Value | 1 | 0 | 1 | 0 | 1 | 1 | 0 | 1 | 0 | 0 | | ||
+ | ^ Digit Weight | 512 | 256 | 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 | | ||
+ | ^ Value | 512 | 0 | 128 | 0 | 64 | 32 | 0 | 16 | 0 | 0 | | ||
+ | ^ Total | 692 |||||||||| | ||
+ | |||
+ | Now whats important to note is that the DAC does not have an internal register so it doesn' | ||
===== Major Challenges ===== | ===== Major Challenges ===== | ||
===== Resources Used ===== | ===== Resources Used ===== | ||
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