
Let's Build a Video Card - eb0la
https://eater.net/vga
======
mrspeaker
The "8-bit breadboard computer"
([https://eater.net/8bit](https://eater.net/8bit)) series is phenomenal. The
videos are so clear and so well explained - after watching them I ordered the
clock module kit, and now I'm addicted to electronics. Before, electronics
seemed so abstract to me. After watching the videos and messing around with
the kit, I was able to come up with an idea for something I wanted to make and
then (fairly) confidently IMPLEMENT it on a breadboard.

Ben Eater is a fantastic _teacher_. You forget how different "knowing" and
"teaching" are, until you get a great teacher!

~~~
andyguzman
YouTube randomly recommended the first part of the video card series to me a
few weeks back. I'd never seen this channel before. I checked it out just to
get the general idea of what he was doing but figured I'd bail on it a few
minutes in once I couldn't follow along anymore.

Instead I got completely sucked in. His explanations were so clear I was able
to understand the majority of the process and could possibly even replicate it
or guess at the next step after watching for a bit. I felt like I learned more
in that 30 minute video than I did in my whole year of high school electronics
that scared me away from this sort of thing twenty years ago. My interest in
doing some small projects is definitely piqued now.

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peterburkimsher
I'm interested in learning more about VGA and HDMI, because I'd like to build
a hardware freeze button.

On an old church projector, there was a button on the remote so I could freeze
the screen. Then I could switch from PowerPoint to QuickTime Player (or
whatever else) without disturbing everybody who was watching. Newer equipment
(some projectors, most TVs) lack this feature. I'd like to build a box that
stores the current frame in RAM, and has a simple toggle switch between the
stored frame or the live video feed.

After a recommendation for the NeTV, I asked bunnie, and he said that the
NeTV2 is a good choice for HDMI. It's pretty expensive though, and doesn't
support HDCP.

[https://github.com/AlphamaxMedia/netv2-ideas/issues/21](https://github.com/AlphamaxMedia/netv2-ideas/issues/21)

If anybody else has some guidance about how to proceed with this project, or
some mutual interest that could translate into nagging me to actually do it,
please get in touch!

~~~
nitrogen
If an off the shelf solution is okay, look into live veejay/VJ software and
hardware, or maybe game streaming/screencasting or other live broadcast tools.
You can add VGA and HDMI capture cards to a computer, then use software to
pause or switch inputs.

~~~
peterburkimsher
Yes, I bought an Elgato Cam Link 4K recently, and I could do it with CamTwist.
I'd rather reduce the lag though, and the physical size/complexity of an extra
computer.

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BubRoss
I have watched these videos and they are really facinating. I wish there was
more stuff like this and less vague clickbait titles.

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db48x
All of his breadboard videos are great, but I was hoping for a few more
episodes in this one. You can't call it a video card if it doesn't plug into a
computer, right?

~~~
cabaalis
At 3:00 into the second video, he talks about hooking it into a computer. [1]
It does a quick flash to what might be his breadboard computer. So I think he
intends to connect this to the computer he has built.

1\.
[https://www.youtube.com/watch?v=uqY3FMuMuRo](https://www.youtube.com/watch?v=uqY3FMuMuRo)

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Lt_Riza_Hawkeye
Why is javascript required to deliver text on a screen?

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Cycloneblaze
I was surprised to read how much his materials cost for this. $88, all told -
you would think building a (pretty much the simplest possible) video card
would be cheap!

~~~
Norther
$56 of which is breadboard and hook up wire - I'm sure it's possible to have a
custom pcb fabbed for about $20,and if you do small runs to have the pcb cost
drop to less than $1.

~~~
opencl
You could also buy the breadboards for ~$2 each on aliexpress.

~~~
petschge
But then you get crappy breadboards that once in a while gives a bad
connection. Without any visual clue. That can be very hard to debug,
especially for the hardware newbie Ben Eater is teaching. Spending an extra
$50 to make the process hassle free and enjoyable is money well spent.

~~~
bcaa7f3a8bbc
Better yet, use wirewrapping
([https://en.wikipedia.org/wiki/Wire_wrap](https://en.wikipedia.org/wiki/Wire_wrap))
instead of breadboarding, so quality of the board doesn't matter. Buy a
wirewrap stick (20 USD), some crappy perfboards from China (10 USD), some
wires (5 USD), some long DIP headers (10 USD), and you're good to go. You may
still need two or three breadboards for quick experiments.

I'm currently working on a homebrew Z80 computer. I'm at the stage of moving
the preliminary designs to PCBs, but from my experience, wirewrapping is a lot
better than breadboarding when you start building circuits with many signal
wires. Breadboards are quick and simple at first when you can "plug and play",
but it would quickly become a nightmare when the number of connections and
wires exceed 200. It may be a less concern for a modern microcontroller as i2c
and SPI are serial interfaces, but on a 8-bit computer, you'll hit this number
_really_ quickly, because the system bus is 24-bit (16-bit addr, 8-bit data),
parallel. A bus driver using two unidirectional buffer has 24 x 2 + 8 = 56
wires, two RAM chips have 48 wires, a ROM has another 24 wires, it's already
148 wires now for a bare-minimum system without even an I/O port. It will get
out of control soon. Also, a 16-bit machine will become a nightmare even
quicker as they have 32-bit bus.

On wirewrapped boards, you'll never get a bad connection without any visual
clue, the connection is as solid as soldering, and there are no jumper wires
hanging in the mid-air to stop you from probing it using an oscilloscope.
Strongly recommended, to learn more, search keywords "wirewrap electronics" at
YouTube.

~~~
duskwuff
> some long DIP headers (10 USD)

You're severely underestimating the cost of wire-wrap sockets. They're a low-
demand item, so they're rather expensive; a few dollars for each socket is
typical, and DIP40 sockets can get into the $10 range. (The sockets will cost
more than most of the parts in them!)

~~~
bcaa7f3a8bbc
> _You 're severely underestimating the cost of wire-wrap sockets. The sockets
> will cost more than most of the parts in them!_

Which is why getting them from China is a good idea. I'm building the real
thing and I'm well aware of that, but I've found a very economical solution:
I've found that buying single-row 40-pin sockets, like this one
([https://www.aliexpress.com/item/32959627004.html](https://www.aliexpress.com/item/32959627004.html)),
is a good low-cost alternative to wirewrap sockets, it only cost you one
dollar each.

It's not extremely easy to use, as you have to cut them and manually plug two
rows of them to make a poor-man's DIP header, but not difficult either, and
doing it is straightforward. Also, if the socket is too rough for the
components you need (for example a heavy ZIP socket, or a DIP-40/64 chip), I
found you could install the wirewrap DIP header to the board first, then plug
a generic, cheap DIP socket on top of it, then plug your ZIF socket on top of
those.

The only real disadvantage is the increased weight and height, so the solution
is not very elegant, but hey, one 40-pin header only costs you one dollar, 10
dollars buy you ten 40-pin headers, which is good for ~15 chips!

