Build an 8-bit computer from scratch

This project looks awesome, and I may purchase Ben's kit to do with my 7 year-old son. My love of computers and software was largely inspired by the 6502 processor. I grew up with the commodore VIC20, C64 and 128 and reading books by Rodnay Zaks in the 1980's. https://en.wikipedia.org/wiki/Rodnay_Zaks

Perhaps I should look to see if any of my old books are still at my Dad's house. This one is going for nearly $1k on Amazon. Not sure how a book from 1981 can be sold as "new" but wow.

https://www.amazon.com/Programming-6502-Rodnay-Zaks-1981-09-...

It's literally just a static page that's dumped out of a JavaScript file, Shopify iframes excluded. But if you want accessibility issues:

* The header image, saying “Ben Eater”, has no alt-text. That would be fine, except the letters are individual SVG paths.

* Likewise, the social media sharing buttons also have no alt-text. A screenreader will just see four images with links at the beginning of the page.

* The YouTube videos are constructed out of multiple links without text each, including SVG images.

* The YouTube video links open into the same window, harming usability. The "target" attribute should only really be used in sites built out of frames, and this is not one of the exceptions.

* My screenreader-type program, in "just read the proper text" mode, misses half of the headings. Outside of this mode, I have to sit through over a minute of drivel before the content, because there's no skip-nav link, and then again for the video links. (This one doesn't quite count, because it's 'cause my screenreader-type program sucks and ignores aria-hidden when I set it to "all". But the lack of skip-nav is an issue.)

* Can't even read the plain, boring old text without JavaScript. This in itself is an accessibility issue.

I got bored at this point, but I'll list some other issues I spotted while looking through the dynamically-constructed DOM:

* Identical SVG images are copied-and-pasted throughout the file, but with different CSS styles – some browsers might waste time re-rendering.

* The page makes seventeen requests even with external JavaScript blocked, eleven of which are to external domains.

* The DOM contains, no joke, eight consecutive s. The removal of some of these wrapping s makes no perceptible difference to the page.

* Mixing and matching semantic and non-semantic HTML tags, confusing certain "reader mode" tools.

And it turns out that this page is actually multiple pages, with no machine-accessible links between them, bundled up into one file stretched across multiple URIs. This is not the proper way to handle caching the next page. I'm struggling to articulate how bad this is.

When I click on the "kits" page, random loading animations partially obscure the top of some of the paragraphs as it tries, and fails, to add some kind of inline purchase widget. There's significant DOM bloat, and displaying the page takes up an entire core of my laptop.

Because of the caching failure I failed to properly articulate earlier, refreshing a page other than the one you initially clicked onto causes a cache miss for all of them, and the retransmission of the HTML page (though fortunately not the thirteen pages worth of stuff, which are stored in the ~0.2MB JavaScript file).

Loading the "kits" page directly and following all of the instructions the page provides (not my default configuration) causes my nice new shiny laptop to max out a core for three seconds while the browser requests the website, waits for the request to complete, parses the HTML, requests the JavaScript, requests the CSS, compiles the CSS, renders the DOM according to the CSS, compiles the JavaScript, runs the JavaScript, repeatedly polls something due to a setInterval call, performs 9 DOM Events (notorious for being the slowest API of the web), recalculates the style for and re-renders the DOM, completely hangs for 0.3 seconds for reasons unknown, recalculates, re-renders, runs some DOM events, fires off DOMContentLoaded (prematurely, not that the browser has any reason to know that – this might have accessibility impacts), runs more JavaScript to mutate the DOM further, performs several dozen incremental style updates and multiple repaints, fires off another DOMContentLoaded event, fires off the load event, fires off yet another DOMContentLoaded event, and another, and another (in amongst repeated recalculating and repainting of the DOM), fires off two more load events, etc.… Leaving behind one and a half seconds' worth of leisurely garbage collection after the page has finished loading, meaning I can't scroll until 4½ seconds after I click onto the page.

This is the only computing device I own capable of rendering the page in less than five seconds, even with my very fast network connection. Normal websites with an order of magnitude more writing, plus images and links, take an order of magnitude less time to load than this.

This website is not good. But it's nowhere near the worst out there – in fact, this would probably be in the top 60% of pages I use regularly, if I did.

The description says:

> I built a programmable 8-bit computer from scratch on breadboards using only simple logic gates.

Sorry, but this is slightly incorrect. First, he is using ready-made adders in ALU which are not "simple logic gates", second he seems to use ROM in control logic which replaces tens or hundreds of logic gates one has to use of they don't have a ROM and a programmer.

If I was building a CPU, I would make 1-bit ALU and shift data bit-by-bit to save ICs because 1-bit ALU requires 4-5 simple ICs and 8-bit ALU would require 8 times more and that's too much.

Next, I would use 4-bit registers instead of 8-bit because 8-bit register requires 2 ICs and 4-bit register can be implemented with one IC. Also it allows to reduce the number of wires and amount of work to connect them. This makes CPU slower though because it has to access memory twice as often.

Also I was surprised to read in comments that in some universities students are designing CPUs as a practical project. Must be interesting.

Applied Science channel is worth mentioning.

I think a big part of the reason why people don't care about accessibility anymore is because you can't make a website without someone pulling out a Bible-length list of asinine complaints, and that is for a site "in the top 60% of pages".

I know that I have stopped caring for "accessibility" almost entirely beyond the most obvious things. Most of these complaints are either totally inane and unnoticeable, or will affect so few people over the site's lifetime that I can count them on one hand. I think it's good for people to try and make your website as accessible as possible, but there's a limit to how hard you can indignantly demand people bend over backwards for you.