first Portable and I need a little help

Guest · Post by **Guest** » Sat Jul 31, 2004 6:03 pm

I've started working on my first portable yesterday,
I've finished wiring the composite video but still have to do the power , is there anything I should know before I attempt it. as I only have the unit I'm working on and only have one back up available, which I don't really want to cut up if I don't have to.

Also on the original guide to making a portable something was mentioned about a passive matrix not working as well, or having in compatiblity with all games.

Actually beyond that does anyone have any recommendations for the best screen to use if i'm looking to spend as little as possible but have full compatibility.

Post by **SpongeBuell** » Sat Jul 31, 2004 8:23 pm

Cut the thing up, it's worth the risk. Heck, it worked for me, and things like that always backfire for me. As for power, it uses a 7805 regulator, which is that little black ship outside where you cut it. The 7805 takes any voltage between 7.2 and 35 volts and knocks it down to 5, which is used by the motherboard. Because of this, the atari is very forgiving and will let you power it pretty easily. As for a screen, there are active and passive matrix lcds. Passive is blurrier for movement, and hard to see some games with. Active is more common and about the same price. As for a good, cheap screen, try the PS1 screen. It should work, though some don't really like ataris, so I dunno.

Guest · Post by **Guest** » Sun Aug 01, 2004 7:50 am

Thanks,
If this works I probably will cut up the back-up and make another portable atari, I have a really cool idea for a variation.

Guest · Post by **Guest** » Sun Aug 01, 2004 8:01 am

I need one more bit of help

on the original general step by step the conection of the video potentiaometers, and the resistor refer to spot "A"

Is this spot A on the motherboard, the 500k potentiometer or just a point were they meet.

Post by **SpongeBuell** » Sun Aug 01, 2004 9:22 am

all 5 wires (pins 2, 5, 7, 8, and chroma are joined at spot A. for pins 5, 7, and 8, make sure they meet AFTER the needed resistor or potentiometer.

Also, take a look at http://www.doomportables.org. I made a couple of nifty how-to's, including true stereo sound.

Guest · Post by **Guest** » Sun Aug 01, 2004 10:09 am

So they reconnect to the motherboard then.

Post by **SpongeBuell** » Sun Aug 01, 2004 10:17 am

the wires connect to the motherboard, then to a potentiometer or resistor if needed, then together again. I think/hope that is what you mean.