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Fixed the Color Bar Bleeding

A project log for SS Minnow - 8-bit Game Console

Building an 8-bit game console based off of the 6502 and an ATMega 162 (for advanced I/O) .

trappermcferrontrapper.mcferron 08/12/2018 at 19:210 Comments

Wow it's been about a month since my last post.  I was away for a few weeks so I didn't have chance to work on it.  But now, I've fixed the issue!  

My hypothesis was correct, however the delay was longer than 200ns, it was more like 500ns - I had a good friend help walk me through the datasheet to fully understand this.  He recommend I order delay line chips - I did just that, I ordered 2 of these (one for the red bit, one for the blue) - Maxim Integrated DS1100.

Unfortunately they only come as SMTs and I need DIPs for the breadboard.  In the past I've used protoadvantage.com to solder a SMT->DIP connector for me - but it's quite expensive - so I decided to try myself.  Fortunately Schmartboard offers these pretty great SMT->DIP boards with the solder built in, so you just have to heat it up and it binds to the chip:

https://www.youtube.com/watch?v=-32orELxkpE

I ordered two of these - and wow I actually did it on the first try!!!!  Here's a pic:

Then - after some trial and error, I hooked it all up and boom! The red and blue color timings are the  same as the green - and there is no color bar bleeding!

There is still some minor interference, they aren't as crisp as I like.  This seems to be a result of the delay lines - I need to play around with my capacitors and see what's going on - unfortunately this week I can't get to it, so hopefully next week I'll post an update.

After I fix the interference the next step will to be to draw per pixel detail on the tiles instead of color bars - this will require quite a few hardware additions to meet the required timing, I'll post some details on that as I'm getting started.

I just noticed I had another follower!  Wow you guys are great - I'm glad there is some interest in watching me stumble blindly through this :)

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