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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Good call, BDD. I had checked continuity but not voltage. It turns out Vcc was quite low in that area of the board; now it isn't and the DS1813 is working again!

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"The key is not to let the hardware sense any fear." - Radical Brad

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Has somewhat evolved in the world of tech support: "Are you sure it's plugged in?" Being the first thing I would ask when I worked at Dell tech support in the late 90s.

I found asking that tended to get the 'of course it is' response, even if it wasn't... on the other hand, asking them to remove the mains cable (at both ends) and then replace it would often result in an embarrassed 'oh, it's working now...'

Neil

Is it plugged in? Is it turned on? Have you tried turning it off and on again ...

https://www.youtube.com/watch?v=5UT8RkSmN4k

-Gordon

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--
Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

Ben Eater only uses a 0.1uF cap I believe. He has said that he needs to redo that reset circuit, but he's only got a million-something views on youtube of his board doing cool things. Ya know, little things The point is that you shouldn't need super specific values, though I do take everything Garth says as gold. Glad it was fixed with BDD's suggestion though.



Small victories are important. They keep you going. Though, having it work the first time is more than just a 'small' victory. Great job!



Good point. That would tell you a LOT more than just a probe or scope.

Good looking board by the way. It's interesting how you actually DON'T have a jumble of wires as usual with breadboards. It's a lot of wires, but not jumbled. They seem organized and honestly because they are so thin you can still see everything going on. You have used the strengths of the breadboard and wire-wrap to create a good design!

Thanks for the update!

Chad

When I put my 6507 board together I too used a 0.1µF capacitor - figuring that if it was good enough for 30 million Atari 2600s it was good enough for me.

And it was, although not 100% reliable and I sometimes needed to push the reset button ... that is until I plugged in a modern 65C22 - then it became 100% reliable from power on.

Weird little things.

-Gordon

_________________
--
Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/

Thanks Chad! When I started, I had in mind that the construction method would just be a kind of interesting novelty. But now I really like it, both for the aesthetic reasons you just mentioned, and also for the speed / ease of construction.

In other news, I did some basic testing of my ACIAs. The "Rockwell" ones all seem fine, except that two of them lost pins when I pulled them back out of the breadboard. The "CMD" ones are at least actual 6551s; 4 of them work, 1 of them spews garbage as soon as it is enabled. I don't really trust them because they look so wonky, so I will probably stick with one of the Rockwell ones.

When I say "testing," what I mean is that I was able to set up a 3-wire serial connection with my old Windows XP laptop and echo back what I type from its terminal emulator. I haven't done anything to check the current draw to see whether or not they're actually CMOS. I may do that after lunch!

Edit: I did that. The Rockwell ones seem to draw around 2mA. The "CMD" ones draw 1mA, but don't work at all when their power supply goes through my DMM!

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"The key is not to let the hardware sense any fear." - Radical Brad