Connecting an LCD to our computer - 6502 part 4 

sadly thats not true :(

@@PeterfoxUwU Yep, usually it is something regarding smoke. As in, "not letting the magic smoke out", or more commonly a "smoke test".

More like "it's on fire!!!!!!" Note the exclamation marks.

@@stevewalston7089 smoke test jajaja i didnt know that

I look away every time I plug in something I build.

Windows (the dos versions) ran on a 8088 so its almost the same but the chip needs to be upgraded

He has no RAM in his system right now. The extra hardware will be a RAM chip. But until this is connected to the bus, the only thing he can work with are the CPU registers.

Indeed, RAM is needed for the stack.

We will get to full color graphics soon sighs

Thing is, a subroutine like that would need to use RAM to store the return address (on the stack).

Yep, the computer pioneers of our era are beginning to go now. Dennis Ritchie, co-inventor of C, passed in 2019. There was somebody else that died recently, but I can't recall who it was.

@@markjones5973 Dennis Ritchie died in 2012

Dennis Ritchie died twice?

@@huguia Typo. I knew he died a few years ago, so I looked it, saw that it was in 2012, came back here and promptly typed 2019. I'm such a dumbass sometimes.

@@markjones5973 good for you

Or rather, the one "primitive tech" channel since all the other ones are just poorly ripping it off.

@@tux1468 Usually I'd be mad about them ripping him off, but to be honest some of them are just as entertaining, but not from an educational point of view.

@@tux1468 Add apionet

@@Amethaz Bro go away

@@tux1468 No❤️

That is awesome!

Well done. :)

Once you know how to read those specs documents, everything becomes much clearer.

That’s really awesome

You both keep up the good work! :)

Even after 10 years having been a programmer ( I mean a professional one) you didn't know this one. so what went through your mind? In the meantime I found 2019 to be a rather fascinating one, most satisfying. Would that make it double weird for you? :-)

"2019 is weeeird"... Oh boy, you thought that 2019 was a weird year...

Erik Nestaas 2020 is weird.coronavirus...

@@eriknestaas2270 lol

We were so naive back then.......

even on a modern CPU, for what this is doing, it's inefficient on a system with even lower memory, it's worse. there's also the issue that every time you want to go and change the output... OUCH! you have to copy-paste several lines of the same code and tweak them just a bit, and hope you don't screw-up its good as a tech demo or proof-of-concept hence why he said the next video will be about optimizing it though, i do have a theory all of what will happen...lol i'm mainly watching this for fun, and also because i'm curious how you take processor and build an actually useful device with it. as for chrome, or ANY modern browser [rather, application] , tbh, yes, quite inefficient. it's now the rule and not the exception that web browsers suffer memory leaks. it starts as trickle, and before you know it, you HAVE to re-start the browser... >.< I use pale moon, myself. Never liked chrome since my first experience, firefox drove me away by taking-away all the features and customization that I used it for in the first place. The reasons go honestly far beyond the scope of developing a single application, though. It's decades of questionable practices, including so-called "rapid app development" and other "innovations" in the tech industry. I started my "serious" programming with these newer languages/tools, and tbh, there are multiple things I don't like. I watch videos like this, and about ROM-hacking, so on. I just facepalm at what's being done today. I have so many ideas right now or projects/systems I'm slowly cobbling-together that are pretty heavily inspired from older technologies/tricks [if not re-implementing them to some degree], or using low-level concepts. Or well, that's the plan.

using a million other libraries or adding extra baggage is why i don't trust jquery, node/npm, so on... javascript is unfortunately so utterly worthless on its own that you need libraries by default. i have yet to see anyone preaching the joys of HTML5 use the APIs right out of the box. they use engines that abstract the crap away. been building my own from scratch. this is a problem plugins didn't have. but "in the name of security" they were decided to be killed-off. hoping to switch myself to full native or web + native development. I just also don't desire to touch such things as C++, either... *shudder* And I suspect my next obstacle is going to be these corporations for "our security" going full gatekeeper via the online stores. note the 'recommend' setting in win10 is to ONLY install from the store. There's a lot of programs that this can kill-off because there are so many reasons it can't or WON'T appear in e-stores. And then it might even force others into needing to go through additional licensing programs [i suspect this is the future for hex editors and programs that have a reputation for being used in hacking, especially reversing proprietary formats and facilitating piracy/emulation] libraries aren't in themselves bad, the way they're used and maintained is. mainly the mainstream ones. admittedly, i used to do this, jquery's main use: $("some_element"). if this is what you need to do, document.getElementById("some_element"). note this is discouraged. same with directly using XHR, which you could cut AJAX out in 90% of all cases. bootstrap, jquery, so on, should only be used for sites like twitter, youtube, so on... [if even there, but google did jquery, twitter did bootstrap... small sites/apps don't need and shouldn't use them] it's mainly executives who don't know anything about the company and the industry leading this push. look at commercials where the only thing they can brag about is : "patented" , "proprietary". this just simply means they keep their methods secret and have gone through the [very expensive] process of facilitating the legal right to sue people for trying to copy their product/service/process. speaks nothing for the quality of the product/service. this is also what i find funny about norton/lifelock. "with all these data breaches happening..." , why these happen : governments [NSA caused ransomware outbreak by not disclosing the exploits to computer companies, cuz THEY wanted them to look for possible 'terrorists' via unethical, immoral, and ILLEGAL spying mechanisms] , databases get breached partially because executives don't want to pay money to people to properly fix them, INTERNET OF THINGS [that shouldn't be connected to the internet], cloud computing, streaming [latter two are ultimately DRM mechanisms cuz it turned-out the fatal weakness of DRM was, and always will be, client-side code/data. it's not security/convenience as the reason, it's copyreich] i'm personally waiting for the next big crash, it's inevitable this will happen in the next few decades. we're actually making things less and less compatible with each other, which will lead to a lot of data rot, FAST. [like flash being killed, at least the open source community is working on it.] we're connecting EVERYTHING to the internet, increasing VASTLY the attack surface for hackers to target. we're increasing bandwidth usage and the infrastructure wasn't designed for so much traffic, nor was it properly upgraded in many cases. we're adding countless lines of tightly coupled dependency/overhead/boilerplate code and adding many extra layers to code management that don't belong there. [oh, and writing macros to generate code/data that the COMPILERS should be doing automatically] everything is obsolete when it's released, nothing released is finished. W3C members and browser vendors are STILL having a pissing contest, this is why APNG failed and GIF is STILL in use. [This is also why CSS3 suffered that prefixed properties BS.] Proprietary code is still supported in open source bodies [EME, aka DRM for the web, glorious "champions of internet freedom" , Mozilla, actually switched their stance to endorse/support it] Something's gotta give... [oh, and programmers who actually care or know how to do things are quitting/dying, assuming the 'supervisor' or an 'o' aren't telling them to basically, not do their job, cuz it costs money, anyways] I'm hoping my own code base will avoid some of this since I'm trying to axe the third-party dependencies as much as possible... Even then, there's a lot I can't avoid, like the internet globally suffering an outage, or the possibility/inevitability M$/Crapple are gonna tighten the noose around developer's necks since as it stands, I [and many others] can write and publish code/software which they don't have the ability to control at present. [End users, likewise, can still download/install/execute/[de]compile that code.] welp...another text wall... never thought programming and tech, generally, could be so...political... >.< i just want to make + play games, dammit!

yes and no. the HTML5 Canvas/webGL and WebAudio APIs are absolutely miserable if you don't have a library. even if it's an in-house solution or lightweight, it's still a library/engine/framework, it's still basically necessitated because you're dealing with simple state machines that don't have any concept of what an actual program [especially game/animation] needs... a 2D game needs a concept of tiles/sprites, which requires some additional systems and data structures. a 3D one needs models, skeletons, possible inverse kinematics, [shaders,] etc... If you implement that wrong, performance is bad, you could even potentially cause damage/stress to the machine/ [something people don't seem to like mentioning about GL is that you really shouldn't touch it if you don't know what you're doing. just how it's not technically necessary even for 3D UP TO A CERTAIN POINT] all games need asset management and audio playback + audio looping. HTML5 doesn't do this out of the box. Neither does C/C++, so on, but we already have libraries [and...MASSIVE engines/frameworks] to deal with this for native applications and...mobile/console. Web had shockwave, java, Flash, Unity as the main ones. They each had their use, and I'd argue still have benefits if people can do ANYTHING besides freak-out about code exploits and "proprietary black boxes". More so, Flash. Shockwave's plugin is horrible, I hated dealing with it. But, some of my fav games need it. Unity is still a mess post-webGL [especially as an impenetrable proprietary black box with code doing god knows what] Java applets were neutered and I don't like the "everything is a class" blueprint-oriented nightmare java helped create. Flash's format, at least, is honestly great if you consider bandwidth and flexibility/extensibility. Parts are a nightmare to parse because that's how serious adobe/macromedia were about making the files SMALL. coupled with the AVM you had pretty much the only general-purpose game engine that's arguably useful, ONCE you figure-out how to use it. You don't have to monkey-patch flash or add loads of boilerplate to make even a simple/'mediocre' game. You can, and a lot of modern flash games do run entire frameworks behind the scenes like box2D or Flixel, but you never NEEDED to. A lot of the limitations with flash are also imposed, now that the format and AVM are documented so thoroughly, it's not out of the question to bypass the limitations or improve the parts that don't work. Just as an asset format, I wish SWF or something like it, stayed. That's one of my projects, but it's time-consuming and tedious, and I''m spread too thin. I probably sound like an Adobe shill, but I've long since lost my respect for them as a company. Currently I don't plan to collaborate with them or any other large organization since I don't trust them. I also don't expect adobe to do anything more than allow it to happen like they already have with SWFmill, FFDEC [which sourcetek/sothink hate! (:< ] , haxe/flashdevelop, flashpoint, etc... Anyways, I just feel the SWF format, itself, has far from outlived its usefulness. Regardless, it should be a user CHOICE to have flash as much as it is to not have. but the "open web" community has demonstrated they're not entirely open [Encrypted Media Extensions!!!] , and aren't open-MINDED ["flash needs to die, flash users are stupid, flash developers need to adapt or die with adobe despite themselves doing NOTHING WRONG"]. There are other things, but I no longer can find the sources [suspicious!], plus don't really want to drag THAT discussion on much longer. I'm worrying about things I shouldn't have to, and don't want to. Which is ANOTHER reason good and potentially good developers are LEAVING the field, especially veterans and disillusioned newcomers. I am currently trying to transition to Haxe. I'm cautiously optimistic Johanthan Blow actually achieves all or most of his promised goals because: I like js for small little macros [converting hex, Caesar cipher, countdowns, so on] , not full-fledged programs C is still a bit arcane assembly isn't feasible unless i target a retro platform where asm programming is decently tolerable actionscript is basically dead C++ is NOPE python isn't really supposed to run large applications and the whitespace sensitivity will hang you quickly lua needs an interpreter if you plan to USE it Rust just didn't quite impress me Java is too strict and the devtools keep ADDING LAYERS [AND NEED JAVA INSTALLED, which while i have, is outdated and i can't seem to update] Haxe still hasn't impressed me, really. But, better than manually writing JS and I CAN compile to native applications or the Neko VM at some point. As for NPM and all : yep... companies and the desire to get hired by said companies. i actually DON'T want to be. freelance or something? fine... chain of command consisting of people who should not be considered 'qualified' to make decisions? NOPE... [which tbh is just ONE reason] i've seen enough blogs and portfolios. same reason people remove their older works "silly me, i was so dumb back then!". the code style and design choices? sure, i'm ashamed of SOME of my stuff in those regards. but yanno what? i'm proud i can say i did it at all, that i completed it. this has some not nice code and uses...jquery: crystalien-redux.com/unrelated/ETX/apps/web/marsTrans/MarsTrans.html but, i can say i FINISHED it, and that it does EVERYTHING i wanted it to. [and it still works to this day!] i might update it in the future, i might not. and two big changes will be externalizing the messages array to a JSON database [at least converting it], and trying to pull jquery + jscrollpane OUT. i settled for that at the time because CSS3 was giving me problems [THANKS BROWSER VENDORS AND W3C!] point is, it means more to me this is done. if a potential employer cannot understand that, if they cannot understand the particular problems that i had to solve to make this work, then they don't deserve me, and they aren't qualified to hire employees. programming, engineering, science; are about developing practical solutions to actual problems, finding the sometimes illusive answers to important questions. companies and standards organizations lost sight of this, obviously. infomercials show it nicely with the insane majority of products you just don't need and can solve the supposed problem with your existing products "special tray to cook your bacon in the microwave!" and common sense. a handful are practical, but MOST aren't. same goes with frameworks and some of these "features" [like 'the cloud'] they added to software. i lost it with the M$ solitaire when they started bragging about the "innovations"... there are CLOUD-BASED games that UP-FRONT let you export your data to A FILE and vice-versa. and tell me why i need to watch ads on a card game that i could easily play in meat space for basically free [cards are cheap, much cheaper in the long run than subscribing to the premium/VIP version] if i wanted? their only true innovation was the extra modes. even then...pft... i could buy like 4-8 decks of cards and play HUNDREDS AND THOUSANDS OF GAMES. didn't need shiny new graphics, didn't want ads, and i fail to see the save data for that game weighing-in even at a KB, easily stored in a plain .txt file or copied to a text/email >.< well, more time basially wasted ranting bout this...sigh... however, the site i'm trying to use is suspiciously not loading at normal speed, so i can't play my crappy casual games, anyways... >.>

engine/framework/library are a bit ambiguous at times. well, accessing the HTML DOM is a simple/small action. jquery's most famous use is to do exactly that. again, for a very specific type of project, it makes sense to bring those frameworks in. but tbh, decoders don't need anything sufficiently advanced, either. reading a PNG could be done with DataStream.js [makes dataviews easier to work with] , zlib.js, and then the PNG-specific bits can be written on both of those. file parsing also usually is the reading of an array, or several...XD. i've reversed or partially reversed a few. seen arrays and other tabular data a LOT. chunk-container types are also surprisingly common. the libraries using libraries using libraries is one main reason i don't use NPM, though. i do understand how SOME of it happens, though. there are a few libraries i want to use in my own, or have the option to, i fear some wrapper objects/instances might need to be used...BLEK! i'm not saying this is the most common reason. 90% definitely is "look, i made an NPM library, you should hire me!"

On my computer: In C++: 8kB In Rust: 430kB In naked assembly: 1k Even the .class in Java (which doesn't include the runtime so it's cheating) is 417B. OK, this is comparing apples and oranges but it's still interesting.

MGfails noice. Perfect 64 likes.

That would be actually very interesting good idea

@@skmgeek 69 now :)

YES!

If you are interested in self learning, there's a library for the AVR ATMEGA called V-USB that bit bangs the USB protocol using IO pins. It also has example code for emulating a bunch of different HID devices. I made an arcade joystick using it a few years back -- back before you could just buy a pre-made board on Amazon for $12... 😑

Lol !

This is so true

Certainly faster pushing 8 lines of pixels from font memory to display and doing all the cursor bookkeeping while the CPU outputs one byte, then pulses the E line.

NoCake Elsewhere: I am proud of this code I copied from google and glued together

How to programm for beginners: Step 0: Search for your problem on StackOverflow Step 1: Copy & Paste Step 2: Compile Step 3: Profit!

But is the Code proud of you?

​@@aleisterlavey9716Is the proud code of itself?

2nded, Merry Christmas Ben and everyone!

Ben Skywalker

You’ve really summed up how I feel watching this. I graduated (MEng, EEE) 7 years ago, assembly was done in first year before quickly moving onto c. I remember assembly, I remember being taught about how microprocessors work (I scored well on this stuff and software in general), but these videos just make it seem so much easier.

@@alexlovett1991 how is your career if you do not mind me asking. I am studying EE and am wondering how easy getting a job was. I have knowledge with programming in multiple languages, hoping that could help me.

@@TheAcidicMolotov I don't know about where you are, but in the UK being an EEE you shouldn't have a problem at all getting a job. Get your profile on linkedin and you should get recruiters messaging you. That's how I got my first job. After 6 months working I basically had recruiters contacting me daily (which is common for other software engineers I know). I'd be wary about using the phrase 'i know language x' it's best to be honest and say 'I've got n experience in x language' where n could be little, a reasonable amount, a lot etc. If you claim to 'know' a programming language interviewers might have a high expectation for the depth of knowledge. I've been doing java for 8 years, I think I've got a very good knowledge of it, but I'm also aware there's a lot I still don't know about it and if asked by someone about those topics I'd have to answer 'i don't know' It's also really worth getting some projects on GitHub or another public repo that you can add in on your CV. Just having done multiple projects on your own time really helps show enthusiasm.

@@alexlovett1991 thanks for the answers!

Lol I slow video down so I can understand what he says

Yeah, even when I slow it down to 1.25x speed

@@MaxPicAxe that's faster lol

@@vaendryl No , he slows down the time

Holly shit! It's been half an hour?!

Electroboom disapproves

software runs on smoke......let the smoke out, it doesn't run again more

Duh really 🤣

I got the ELEGOO UNO R3 Project Most Complete Starter Kit But I still haven’t gotten very far in figuring anything out that’s why I’m watching a bunch of videos but I’m still confused as heck

I got that same kit for Christmas too! I’ve had a little experience with electronics but nothing crazy, made some cool little projects like a joystick controlled LED grid or a sound controlled motor

I tried to do even the simple stuff but couldn’t figure anything out

Go on their website and download the PDF that they give for your specific kit. From there, read the first four lessons and if you need help finding the right parts, look at the little guide they put on the top of the parts box

Don't tell me programmers can get paid per line. Omg I'm starting to think I could do this job. I just need a partner to debug it all.

@@dustybrown4599 if you can't debug it yourself, you can't code.

@defunctusername haha yeah that's true.

You had way to much time...

@@EDLEXUS yep. I was on a few long haul flights...

Wow! What discipline do you study? I am student for my bachelor of science in Electrical Engineering but I’m also interested in computer science and native level coding

1024 hope the WiFi was good for all those trips to stack exchange

Lucas Viñas really?

If I understood the display datasheet correctly, which in part is just gibberish to me so there's that... the display can run as fast as 350KHz on the slowest functions, so even 1Mhz might be pushing it. With components rated at 14Mhz I think the VIA ends up the easiest option, especially if you need to read from the LCD.

I'm a little late to the party, but in case anyone is interested ... I did this and so far it works! And yes, it was fun to do! The E line needs a NOR gate with one input to an address select line (active low - I used a 74ls138 as the address decoder) and the other input to PHI1out. I connected the RS line to A0. Right now, I can't test higher than 165Khz. I need to un-spaghettify my clock module first. The spec sheet says "... high speed MPU bus interface - 2 MHz (when VCC = 5V)". And there should be a way to generate wait states for higher CPU clocks.

Here's an update. I'm able to directly access the display on the 6502 bus at 1Mhz clock. No 65C22 VIA needed.

You could slap it directly on the bus in this arrangement, but it would interfere with other stuff you *may* want to attach to that bus later on. The CIA/VIA should be your interface to any peripherals.

That's how it should be done. For higher clocks you need to check the busy flag on DB7 before accessing the next register.

I was thinking the same, why not using subroutines? But then I realized it needed a stack and therefore RAM :) well, he still has 32k unused address space. I like where this is leading to.

oh thats why hes not using those... though you not really need a stack or ram to do that ... just store your program counter in a free register (i guess there is a b-register or something) then do all your subroutine-ey stuff and write the program counter back in software?!

urugulu true. Though I am not sure if JSR/RTS could work like that. I should read up on it. My assumption is that it needs a block of 256 bytes at address $0100 it can read/write for the stack.

@@urugulu1656 Nope. 6502 has three 8-bit registers: A, X, and Y. A subroutine like one to display a string would need to make use of A and at least one of X and Y. And, to get to the program counter, you would need to jump to a subroutine and pull it off the stack anyway.

Too bad they never made the 6532 chip in a static CMOS version. If there had been one, it could have been used in this project instead of the 65C22 and it would provide the same 2 8-bit I/O ports, plus 128bytes of RAM which would be enough for a stack (plus a bonus timer). This way the number of components could be minimized by avoiding using a separate RAM chip. It's still doable to use a NMOS 6532, but you won't be able to stop the clock or run it slowly because that's not a static chip.

Seeing this really makes me appreciate the In-System Programmer and the bootloader on my Arduino!

Joshua Bryant put a zif socket on the breadboard.

@@the_jcbone i'll do this so i can stop having to reball my 74181

johnny wolinski I meant Ben. :-)

There's also "chip pullers", specific tools for that; tweezers meant to pull chips evenly on each side. Your plan is a great workaround if you don't have the tools though!

your youtube account is older than me...

The ironic part is that academia failed Ben Eater and he dislikes it for it.

Man that sucks you tried hiring a programmer and all that showed up was some random usb cable

Great interest! I'm doing computer engineering on embedded right now at uni. Jobs are guaranteed and the work is real fun!

@@awesomefacepalm I am actually an electronics engineer student, only figured out my interest a while back xD

@@EagleZH23 great!

LDA is replacing the value of A, so you need it to be RS, then both RS and E, then only RS again. Likewise, STA is setting all 8 bits of the output to the value of A.

Should be able to load the data into X or Y and do binary math on A to improve the code.

This. I'm fully dependent on stack overflow and ChatGPT and this guy is doing wonders with immutable and finite paper.

to iterate you need a register to put the index/address in, which is presumably the "extra hardware" Ben is talking about.

worse, there isn't anything you can put at the end of .printc, without a stack, which needs RAM, which could also be what he's referring to (but that needs a stack pointer, which is another register anyways)

Simon Buchan he has registers it's part of the cpu but he has no stack currently so if the sp changes nothing really happens so he can't call procedures

Doesn't he already have the ram chip and ROM chip mapped to different parts of memory? Or do I just not pay enough attention lol

@@mrcobalt124 ROM only, even if it's programmable, and a two byte IO buffer.

RS you could hook to AB0, so address $xx00 would be an instruction and $xx01 would be a text character

Same

YES VERY TRUE

if you watch to the end he says he's doing that in the next video.

There aren't really "functions" on the 6502! There is JSR (Jump to Subroutine), which stores a copy of the program counter on the stack and jumps to the address supplied; and there is RTS (ReTurn from Subroutine), which reads an address off the top of the stack and jumps to there. You can JSR to somewhere in memory, do a bunch of instructions and then RTS back to where you came from. Just to make it interesting, the PC is actually pointing to the last byte of the JSR instruction, which is the high byte of the address, when it gets copied onto the stack. But when that address gets copied back into the PC, the PC gets increased anyway at the end of every instruction, even RTS; so it's then correctly pointing to the (first byte of the) next instruction after the JSR. So what you might do is have a subroutine that pushes a copy of A onto the stack, and writes it to PORTB; then sets RS, R/W and toggles E on and off, trashing the original value of A; and lastly pulls A back off the top of the stack and does an RTS. Then we can just LDA with the character code and use a single JSR instruction to send it to the LCD module. And that's easily turned into a loop, using the X or Y index register. But first we need some RAM to implement a stack!

Oh, never mind. There's no RAM yet, so you have no stack .....

@@bluerizlagirl Shhh! Spoilers for the next video :)

@@BenEater Best spoiler possible. Cannot wait for the next video :-)

bluerizlagirl I wouldn’t even use subroutines, just create two macros for send instruction and data, use the instruction macro 3 times and loop over a string to send the actual message. No RAM needed, no subroutines needed.

@oH well,lord! A macro is just a block of code you can insert over and over again. Instead of copying and pasting, you define a macro consisting of the code you want to copy and insert that wherever you want to paste it. The computer then copies it and pastes it for you, possibly even making substitutions.

But you do realize, that he like wants to explain how the display works and not how you write asm? He wants to show us, which bits go where.

I thought the same thing at first... But you can't JSR (function call) without a stack to put the return address. Which means you need a RAM chip at address 0x0100-0x01FF.

H x That’s something I was unaware of, thank you!

Supertyp Yes, I am well aware of that. But supposing he was able to use JSR as H x had mentioned, he would still have to implement a part involving those bits, and still have to go into detail. A function would still have to set those bits up, and any way he wrote the code would enable such explanations.

@@mekafinchi He says he's doing that in the next video.

why

I have to watch at 2x because of my family at christmas dinner

No

Look at the speed in which the characters appear. I haven't watch the preceding videos right now, but I would be very surprised if he clocked this CPU with more then 10Hz. :-) That's why he doesn't need delays right now, but of course he will need them once he increases the CPU frequency. But: Even Rom was not built on one day. This is one problem in education. There is only so much information you can put in one lesson before it goes over the head of the student.

Exactly. To get more abstracted languages to just allow you to toggle various bus lines requires all sorts of scaffolding.

I agree with this entire comment.

yes it is. but i think it's more common to use C for that and you also might want to find the appropriate compiler for that