Welcome to Ben Eater's Builders!

Let's talk about anything related to the 6502 microprocessor.
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GARTHWILSON
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Re: Welcome to Ben Eater's Builders!

Post by GARTHWILSON »

Quote:
The primer has a whole list of pre-requisite knowledge that can be hard to get a grasp of (in context of the project or just in theory).
The 6502 primer's prerequisites are spelled out near the bottom of the first page, under the heading "Expectations and nonExpectations." They are very, very basic, requiring only acquaintance (not detailed knowledge) of the things in the list. Someone with absolutely zero background in digital electronics would have trouble understanding the primer; so a couple of books are recommended. The primer is always getting improved, and if I find website recommendations to add for these absolute ground-level basics, I will. (To be honest, I have not really looked; but so far the few I have run across have not been ideal.)
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?
schlachet
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Re: Welcome to Ben Eater's Builders!

Post by schlachet »

I am one of those builders.

I stumbled upon his videos, and it rekindled an old curiosity. I think the videos have their place -- they are uncluttered and are just enough to get going. I randomly found them, and they inspired me, and it eventually led me to forums where far more advanced topics are covered and more rigorous processes are followed. It was a good stepping stone for me. By this point, I'd discovered 6502.org, Garth's site, Dawid Buchwald’s projects, George Foot's YT channel, etc.

I wanted to learn a little about the fabrication side, since it seemed achievable at a low price point. I poured over tutorials and read PCB design reviews. I transcribed Eater's computer schematic to Easy EDA and designed a dual layer PCB for it. I was a little intimidated with manual routing, so my approach was to manually route VCC and then move the components around until it was "easier" for the auto-router to work (judging mostly by via count). I figured at 1MHz and 100x100mm, a poorly designed board would probably still work. I had the board fabricated at JLCPCB, for less than $7 USD shipped! My poorly designed board actually worked, as I just powered it up tonight to see it run a hello world program. I’ve just been continually amazed the whole time throughout this process.

I'm at the point now, where I'd like to proceed further, so here I am. Breadboards are more my speed, but I'm ready to dive in deeper. Not really sure where I'm going next, but I'm excited.
Attachments
my poorly designed pcb. intention was to make a "permanent" version of Eater's computer I could build on.
my poorly designed pcb. intention was to make a "permanent" version of Eater's computer I could build on.
schlachet
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Re: Welcome to Ben Eater's Builders!

Post by schlachet »

Individual_Solid wrote:
For reset, I'd like to actually experiment with a DS1233 (and the required caps/resistors) - not quite as convenient as the DS1813 but it's accessible from Jameco, so an easy recommendation to cart for anyone who is planning to buy the Ben kit.
What’s needed around the DS1233? I’ve been looking for an example schematic to follow.
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drogon
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Re: Welcome to Ben Eater's Builders!

Post by drogon »

schlachet wrote:
I'm at the point now, where I'd like to proceed further, so here I am. Breadboards are more my speed, but I'm ready to dive in deeper. Not really sure where I'm going next, but I'm excited.
Looks very good!

and, well, if you want a challenge - get a keyboard hooked up and make EhBASIC work on it ;-)

Cheers,

-Gordon
--
Gordon Henderson.
See my Ruby 6502 and 65816 SBC projects here: https://projects.drogon.net/ruby/
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BigEd
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Re: Welcome to Ben Eater's Builders!

Post by BigEd »

Welcome, schlachet, and thanks for sharing your story! Do feel free to start a project thread, or to Introduce Yourself.
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Individual_Solid
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Re: Welcome to Ben Eater's Builders!

Post by Individual_Solid »

schlachet wrote:
Individual_Solid wrote:
For reset, I'd like to actually experiment with a DS1233 (and the required caps/resistors) - not quite as convenient as the DS1813 but it's accessible from Jameco, so an easy recommendation to cart for anyone who is planning to buy the Ben kit.
What’s needed around the DS1233? I’ve been looking for an example schematic to follow.
Per the datasheet -
Quote:
For proper operation with an external pushbutton, a capacitor between 100pF and 0.01F must be
connected between RST and ground. In applications where additional reset current is required, a
minimum capacitance of 500pF should be used, along with a parallel external pull-up resistor of
1kminimum.
You can see an example circuit on this neat power module design for the RC2014 backplane, but ultimately is just a power regulator and reset circuit for a 5v microprocessor.
Attachments
SC142 v1.0.0 Schematic.pdf
(9.55 KiB) Downloaded 74 times
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BigDumbDinosaur
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Re: Welcome to Ben Eater's Builders!

Post by BigDumbDinosaur »

schlachet wrote:
I am one of those builders...I was a little intimidated with manual routing...I figured at 1MHz and 100x100mm, a poorly designed board would probably still work.

We have an old saying around here: You can get away with murder at 1 MHz. After a while, manual routing won't be all that difficult for you and you'll likely prefer it over auto. We've got builders around here with manually-routed PCBs whose contraptions are running at or beyond 20 MHz.

There is a sticky topic devoted to high-speed construction techniques you may find of interest. It should give you some food for thought on building a unit that can run at double-digit speeds.
x86?  We ain't got no x86.  We don't NEED no stinking x86!
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