The more I study, the less I understand

This was so cool! I wish you were a professor at my school - I literally go to Harvard 😂 but the teaching and humor doesn't compare to your style!

I am just starting out. I am building the Ben Eater computer on a breadboard. I am using the ca65 and ld65 (assembler and linker). I am going to be watching your awesome guide lets says many many times, and taking notes. Ty for sharing.

The NES CPU core acually had the decimal mode circuits still on the chip, just disconnected.

What my professor at a T10 University couldn’t explain in a 1 hour lecture, this guy explained it in 5 minutes. Thanks a ton.

Is this running on a FPGA board ? 😉

It's a shame that you can't tag people here. Else I would be tagging Ben Eater, or The 8 Bit Guy on this video, they'd for sure enjoy this just as I did.

This is cool. I like going back-and-forth between practical and intuitive explanations like this, and the more formal ones.

Your videos are exactly what I like to see in technology videos. Thanks a lot, keep doing them. ❤

feels like wozniak on LSD when he came up with the graphics scheme. So you can't have 3 pixels blue green purple next to each other horizontally. Talk about limitations!

Amazing video! Thanks for sharing the knowledge!

Incredible video to get me started with monads!

Great video. As a side note, there is slight omission in the type of the prelude lookup function, and should be: _lookup :: Eq a => a -> [(a, b)] -> Maybe b_

What if you want to return a more informative error than just returning "Nothing"?

Video memory addresses were often arranged in an unintuitive way - although not always as tricky as in the Apple II. The reason for this is that it was Dynamic RAM, that had to be refreshed within a certain time frame to retain its contents. To create the video output signal, the video chip had to read the RAM in a repetitive way anyway, and if the addresses were interwoven in the right manner, this continuous read operation could have been used as the DRAM refresh.

Amazing.

Great video. Your comment about the zx80 at 16:20 isn't correct though. The glitching as the keys are pressed isn't due to the CPU conflicting with the display circuitry accessing RAM. In the ZX80 the CPU draws the screen itself, and so if it's doing anything else, including reading the keyboard it causes glitches in the video output. Also, why is the outro music about 500db louder than anything else? :)

A crowning achievement of my life

4k = 4096 not 496

I thew my Apple II Reference manual out in about 1999, :(

❤Woz

Well I'm pretty sure I could watch this at 0.5 speed and still have no idea WTF you are talking about. Back to the literature it is for me...

Despite all of its weirdness and limitations, the fact that the Apple ][ had built-in color graphics made it the first personal computer that could be a video game platform. Other 8-bit computers had much better capabilities, but they came later and were able to use custom chips.

I feel old. Apple ][+, two disk drives, amber monitor, Epson MX80f/t

I am always baffled when programmers (who ought to know better) don't grasp, fundamentally, what a sprite is. Maybe it's just too exotic a hardware construct for softees to understand? This is the first time however I have ever seen a serious programmer conflate Apple II shape tables with sprites. This is like having a division routine and calling it a "math coprocessor".

Thank you! Great work! What software have been used to create timing diagram @9:23?

... doesn't mention the z80? Seems deliberate.

I am interested in learning more about 6502 machine language. I have only been working with it on the KIM-1 for about 1 year and I created my own OP Code diagram which included the different addressing modes. That you explained in this video very well. Keep in mind that I am new to studying the 6502 and it's Op Codes, so there may be a mistake or two in my diagram. Please let me know if you find one. drive.google.com/file/d/1stT1klHHyHeuhXuHmm77puHzOgLKEF2Q/view?usp=drive_link I hope this table helps other 6502 enthusiasts like myself. Anyhow, I was interested in the way you were looking at the least significant bits starting with Group One (01) - Which basically repeats everything down columns 1,5,9,D and Group Two (10) - Which repeats everything down columns 2,6,A and E. I could also see how Group Three (11) - Which would include columns 3,7,B,F have nothing in them at all and Group 4 (00) which contains columns 0,4,8,C that do not repeat each other. Now when I look at the most significant bits or the rows across my table. I can see a similar pattern when it applies to addressing modes. Group 0 (0000) and 2 (0010) contain the same addressing modes as you look across each row and down each column. Group 1 (0001) and 3 (0011) also contain the same addressing modes as you look across and down each column.

So well spoken, thank you.

How is that possible that lookup can get 2 parameters. It’s just a function that can get one or not (at least by ur definition). Your definition of the first lookup is not correct. It should be: lookup :: Eq a => a -> [(a, b)] -> Maybe b Don’t know why someone wasn’t noticing before.

This guy deserves a prize. Thank you so much

So monads are actually an admission that sometimes an imperative program solves the problem better, and we produce some elaborate syntactical sugar to return them back into existence. For me it looks like the do-construction is ambiguous.

So, a modad is just a state that is passed through a list of functions, with the output of each function becoming the state for the next function?

In other 1975 events: Linda Ronstadt had her first and only number 1 single with "You're No Good" (for one week in February 1975). Elton John's Captain Fantastic and the Brown Dirt Cowboy and Rock of the Westies both debuted at number 1 on the Billboard 200.

At 0:46 you meant 4 THOUSAND and 96 bytes, thanks for the video!

I built a Neutronics ELF-II in 1980 when I was twelve. It worked.

And then! And then! And then! And then! And then! And then! And then! And then! And then! And then! .... She just enter in a infinite loop XD

Wow! I learn something new every time I rewatch this video (last count: 5). I believe that Rod Holt was the designer of the Apple II's switching power supply. He was recruited by Steve Jobs while working at Atari.

Correction: Atari 810 holds 90K per side, and it also has a microprocessor inside, a 6507.

It's hilarious that every single description given on monads, of which I've now watched or read ~20, will say: "people over-complicate monads, here's a simple explanation", but then go on to give a completely unique & different take on monads. If 20 completely different, yet correct, explanations (totaling over 10 hours of sense description) on a concept can be given... maybe it's not so simple :p This one added something great though, as they all do, so thanks. Monads are very very complex; you essentially must look at it from many different perspectives to fully grok their power as a pattern in programming & category theory. The maybe monad is straight forwards and probably most programmers have implemented it even without realizing. But it is complex even if you don't decompose it back into monoids, consider their relation, and then consider what happens with variants on type signatures, expressions, or generalities. And then considering what may constitute a monad (eg an object may implement it with a method that injects this as the first arg of the binary operation). And then there are extensions like if you want to define overridable default behavior, or optionalness of promotion into the monadic type (which, by necessitating kick-outs into global state in some way, are not possible in haskell but in others).

Funny never had any serious problems with Stack, but maybe I was just lucky. Now I'm making games and there's simply no libraries for that, so had to stop using Haskell. But there's just no language as fulfilling to work with as Haskell, so I'm pretty sure you will be back.

Sorry, what means "DAdj"?

"he clearly forgot how to use the return operator" that line is when i realised this is my new favourite channel

I'm too dumb to understand this.

Hello Steve, I am here watching your video because yesterday I had one of the co-patent holders for the TMS9918, Dave Ackley, sitting in my office. Dave is 87 years old and spoke about the 9918 like I would speak about a project I worked on last year. It was 45 years ago for the 9918. Dave coined the term "sprite" with respect to its use in computer graphics. Considering his name is first on the patent, I believe him! He described how the sprites were implemented and also the circuitry that encoded the NTSC video in pretty clear detail close to what I read later in the patent. To think at the same time (late 70's) I was struggling with trying to understand simple raster-scan timing chains, having to rely on mostly other people's designs (I was 15 years old) while Dave was 20 miles away building state-of-the art graphics chips. At the time if I had a little more design savvy, I would have been pushing for line drawing acceleration and possibly area filling hardware vs sprites, but I am sure would have taken more than the 1000 transistors OR so of the 9918 to implement.

Loved the "coffee resistant" description for the Atari 400 keyboard. Nice to think it did have a positive attribute. I am glad to have not owned an Atari 400. I worked in a computer store in Dallas (The KA Computer Store) around 1980 and Apple II was the favorite child. If someone wanted an Atari, major effort was made to get them to buy the 800 unless they just wanted to play games and do MINIMAL typing then the 400 was a reasonable option.

Very nice video! ...but at 1:00 "Everything had to go through the accumulator" is not totally true (Ack, watching your entire video, I now see you cover this really well and this comment should probably be deleted!) . Many useful operations do not require the accumulator. For example you can rotate, shift, increment, decrement memory locations. Yes, a read modify write operation is performed by the processor on the data, but it, does not affect the accumulator. Instead an "invisible" data register on the CPU (and actually an "invisible" address register) is used. For example to left shift a 24 bit value located at $1 to $3 in memory. (zero page in this case) the instructions ASL $1, ROL $2, ROL $3 would be executed with no impact on the accumulator. This is a lot nicer than having to write LDA $1, ASL, STA $1, LDA $2, ROL, STA $2, LDA $3, ROL STA $3 which you would have to do without this feature and saves a few machine cycles (9 - I think) and code length (9 bytes shorter). Similarly you can increment and decrement memory locations where zero flag is useful if you have a multi-byte data where branch would be used to skip incrementing higher order byte when the lower order byte is not zero after its increment, e.g. 16 bit counter stored in $0 and $1: INC $0, BNE 1, INC $1 (where BNE is branch if not zero +1 instructions skipping INC $1. Hopefully this is pretty accurate, I wrote a ton of 6502 code 1979 to 1982 and NONE since, except I did kind of check my comment using an Apple II emulator I just downloaded with Integer basic ROM model including WOZ's mini-assembler. One final comment, of course if you wanted to do something like add two values in memory or add a constant to a value, then the accumulator would be needed for that.

Great video! Learned a lot :)

This video is amazing. I wish I found it sooner.

_"After many years drinking the functional Kool-Aid, which had no side effects by the way"_ LOL I love that line so much This was so helpful, thank you so much!! This video explains it better than others have. Thank you!