Since my IO scheme seems stable, I ripped up the test wires and repositioned the 6502 and SRAM for optimal wire length.



I am using the same 10ns 512K SRAM, and may look at doing some banking trickery later on.
For now, Address Lines A16-AS18 are just held low. I could have 8 banks of 64K with this memory.

At this point, the only bottleneck that may prevent 20MHz operation in the 6502 circuit is the read function.
To read from say the Sprite Memory, there is about 46ns of propagation before the data is ready.
I have a plan that will divide the clock by 4 for the next cycle following a read, but for now will just run slow until things are working.

After the 6502 is up and running, I will work on the Boot Loading system. I have several options.
I think using an SPI Flash Memory is the best bet, as I can have the logic initialize and read the memory.
The Boot Memory (Cartridge) needs to hold at least 4MB of RAM, more if I plan to go with 6502 paging.

Next stop... 6502 IO Decode System rewired and tested.

Radical Brad

Wanna make a game for the system?
I'm up for it.

As soon as I get the 6502 IO system to where I want, I will post the 6502 ASM libraries.
They include all graphics functions, but no sound functions yet.
Will also include a basic game for reference.

It would be great to have some games / demos coded by the community!
That is one of the main goals of doing this project.

Programming games is made very easy due to all of the work being done by the GPU.
The Cartridge also loads the 1MB Sprite and 1MB PlayField Memories, so the 64K is 100% free for pure program code.
No interrupts or special timing are required on the 6502, and all IO is mapped to location 512.

Vulcan-74 is also going to have single cycle 16 bit math.
I am using the math system that I designed for my DIY CPU, since it is compatible here.


Time has been scarce. Will try to get a day into it again soon.

Radical Brad

What you say sounds really good.

However, the word 'library' itself makes me cringe.
Just like you, I like to see things for myself and work as closely to the metal as I can.
I'm sure all your subroutines will be great, and I'm also sure you wouldn't mind a programmer
trying out his own techniques wherever he may need it.

For example, I wouldn't give up interrupt programming for anything in the video game world.
Makes all the difference.

Very good work.
Cheers.

Sounds good. Being a new 6502 ASM programmer, I have many tricks to still learn.
For those who have never done ASM, I am trying to make the examples very easy.

Interrupts can certainly by used. I just wanted to state that it would not be necessary to use one as the 6502 is completely unaware of the rest of the system. The 6502 is free to access all of the 64K in any way it likes, and does not share the bus with any part of the Vucan Hardware. There are no waits, no ready signals to deal with, and all IO is mapped to a single 256 byte segment.

I have also added paging ability, so that the 6502 has 8 pages of 64K in the program memory.
Paging is ultra basic, and causes the 6502 to reset and execute the program in that page.
So in reality, it is a system that can store 8 individual 64k programs. Still beats wasting 448k out of 512k!

Brad

From what I'd read before from your posts, it seemed clear to me that the 6502 was completely independent with the rest of the hardware.

Without knowing the exact layout of the logic I already see the potential in it (from a 6502 game programmer's point of view). I didn't mean to suggest, by the way, that your system was lacking in any way so as to "force" a programmer to work with interrupts without alternative. I'm sure the system is quite capable as it is.

What you'll soon learn, I hope (if you don't know it already), is that with 'all things being equal', a system (hardware), no matter which, is only as effective for the game player as the programmer who works on it and the good game that's made for it. As I've learned to see it, if "that little something" is not there in-between the opcodes and the game itself, the gameplay will be missing 'something' and the game player will feel it as he tries the game.

With that said and even with this system being as good as it is, c-style 'coding' or the so-called "oop" programming practices cannot yield more quality on it, than maybe more or less the average 'pc-style' DOS-game quality, because of the underlying nature of the practice itself. To program 6502 with excellence you'd better 'think' 6502. Want the game to be a hardware game? Respect the hardware and USE it. Want to program for people to read your sources and say how nice it looks? Then use so-called "well behaved" programming practices and get stuck right in the middle with the crowd (mediocrity). Want to push the limit? Then use every "trick" there is and forget about dogma-imposed rules.

If you had followed the so-called logic design 'rules on the limits', for example, your system as it stands wouldn't exist today. The same goes for every good hardware game.

Somehow, somewhere along the '80s "people" seemed to forget this, and that's how you have professional game 'developers' today under the false notion, for example, that higher 'fps' means better game quality, without any respect whatsoever for the truth of the hardware. The same would happen with your system if they tried it that way, I'm quite sure.

Just some thoughts.

I agree completely with every character you just typed!
What some might call "dirty tricks" or "coding hacks", I call optimization.

Even after reading some 6502 ASM tutorials when I was just starting out, I realized instantly that self modifying code was the ONLY way to fly, and that not using it because it's "dangerous" is the kind of thinking that only a C advocate would conjure up! I am also all for illegal ops, overclocking, and running as far to the edge as possible in order to shave off even a single cycle someplace.

When I designed the Vulcan hardware, it may be the first time in my life that I actually kept to the safe maximum delays and setup times. None of the video or sound hardware runs over the rated "typical" propagation of any IC either. I also chose the slower ICs - if a 74HC came in 12ns and 16ns packages, I always chose the slower 16ns version. This way, I am prototyping with the "worst case" scenario, and when I make another board (non breadboard), it will have almost no chance of failure. I might even be able to get back up to the 40MHz "limit", where the Sprite Generator seemed to start complaining.

So, I really do look forward to seeing what the 6502 programming gurus can make this thing do! My games and demos will be fairly basic until I get my 6502 Kung-Fu finely tuned. When I see a C64 pull off plasma effects, it is amazing considering the slow 1MHz speed and sharing of the bus, so I can't wait to see what will be possible here. Even my PC can't fly around a 1024x1024 bitmap with 80 sprites layed over it without some jitter. Seeing a 6502 do it at a perfect 60 frames per second is great.

Brad

and

Be sure to check out Jeff Laughton's circuit tricks for ultra-fast I/O, trapping unused 65c02 unused op codes, at http://wilsonminesco.com/6502primer/potpourri.html#Jeff . He's working on some others for the 65816, using the WDM op code and its operand, which can even do two I/O operations, in one case even three IIRC, in the two-cycle instruction. And since it's not memory-mapped, it's always just as fast regardless of what's in the DP or bank registers.

_________________
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?

Okay, some thoughts.
I'll write this much. From my point of view you need all the good information you can get:

With regard to learning new techniques, maybe let some of the 'demoscene' people find you, and let them program for the system. You'll soon be able to learn many techniques that way, if they choose to try out the system (I don't see why they wouldn't).

With regard to seeing what can be done with the system ===effectively===, from a game's perspective, I'd say make sure you have a pretty good and simple game running for it, and then see how it works and how it performs from a professional hardware-wise point of view. If it performs well, then the sky's the limit.

I'm sure my words won't ring well in the ears of those who swear by 'c' and the "oop" practice, but here's truth: The so-called "well behaved" style of programming is essentially the blight of 'political correctness' brought down into the essence of programming, in order to destroy it. Take for example changing opcodes 'on the fly'. Is it dangerous? Sure, it's "dangerous" to whomever is trying to control each byte of your program, or to the deficient programmer who tries to understand your work to ride on it and trash you along the way. They indoctrinated young programmers with this kind of misconception, and the indoctrination worked quite well for them. Look at things now, when 1MHz systems can not be matched by 2 or 3 GIGA Hz systems; and it's getting worse, but it's getting good for me.

So yeah, it's a fact that your 'pc' (running who knows what speed) can NOT outperform or even match to precision a simple 1MHz 6502 with good hardware, in terms of smoothness and perfect video display. It wouldn't outperform it even if they brought it up to a cpu clock speed of 10,000 GHz while keeping the 6502 under 1MHz. It can't do it because of principle. It's not the speed, it's something else. Solid principle. All "old school" professionals know this intrinsically, and I'm sure they laugh at hardware designers today as they come up with ridiculous ideas such as "adaptive vsync", to try and "correct" really basic hardware design flaws; I know I laugh at it myself.

The 'philosophy' of pc-style systems and those working for it has always been based on business without regard or respect for any truth outside of business-thinking. For example, we have 'folders' instead of directories, 'libraries' instead of kernals (not aimed at you by the way, just truth), 'notepad' instead of a text editor; web pages with dark text over a white background (instead of the smarter darker background/brighter text contrast -- brighter backgrounds being used, I'm almost sure, to resemble office paper, go figure); "opening" a program instead of running it, and "administrators" in our own personal home computers. And let's not even mention keyboards which come in different "flavors" and that sort of nonsense. Their 'philosophy' is different. Talk to them about 'objects', 'structures', 'classes', 'frameworks' and "privileges", and they'll like you if you're one of them. Dare to mention concepts like gate propagation delays, synchronized timing or even the word "assembly" itself, and you'll see what they're truly about. To them, JMP's are "illegal", "goto" commands were banned in college and 'good graphics' means nothing more than a flat static high resolution image on the screen; 'sound' is nothing more than a 'wave' file and games were silly things made just for children; and right up until they saw money in the word 'game' itself, that word was merely something to be avoided and despised in their "computer world" and in their eyes. But none of it changes the facts, though.

Now those same people are the ones making games and game consoles, if you can believe it, and they truly think they do make better games than the real thing just because they have smaller pixels, more colors and more RAM. And on top of it they really think that a high level language is better than the real thing and that using "drivers" is better than direct hardware access. Right.

The pc, as a computer, has always been a mediocre system from the ground up in terms of design, even with this day's improvements. It has always lacked. It has succeded in persistence, but it is lacking in technical terms. When the pc-xt ran at "4.77"MHz, for example, in truth it barely ran maybe a little over 1MHz because the clock had to be stupidly divided by four due to poor design choices. The pc keyboard is read serially through a microcontroller (talk about overkill), and this microcontroller can and in fact does interrupt the CPU when a 'key event' happens. NOT necessary, not good. I heard once that the reason they used a microcontroller for the keyboard was because they had a whole bunch of microcontrollers laying around and they wanted to find a market for it. Well, they found a market for it alright, but look at what cost.

So which method works better for a smooth game, would you say: Reading the keyboard serially through a middleman and compromising the entire architecture's and system's steadiness each and every time the player presses a single button, or peeking the state of the key matrix itself, straight from memory and directly from the 6502 without any unsync'd interruption? The latter, of course.

Furthermore, for a game and between two systems, how can the game response be comparable at any rate, when one system reads the input(s) serially, while the other one detects TTL changes in parallel, at the gate level itself and for each single button 'in real time'? The answer is there is no comparison there. How could the lower system ever hope to match the better system while working on that basis? It never could and it never would, that's the fact. The best it could hope for is to achieve some kind of approximation to the better system; it would be an emulation, that's all. Never the real thing.

The first time I looked into the pc to program it, I knew the design couldn't be very good when I saw that the system issued a hardware interrupt -of all things- if a division by zero was attempted. I remember that I laughed when I first saw it.

Here's a little test for you or for the reader, in order to help you open your eyes a little more to see what you're REALLY working with when you're working on any 'pc': Make a simple boot up program for it to run a loop, to flash a screen white and then black repeatedly, more or less let's say 700 times a second, and with each change send out a bit through some port (if there are any to be found still), TTL high for the screen white and then TTL low for the screen black, for example. If you do it correctly, you will see for yourself on the screen and on the oscilloscope why you can never get perfect true video display from a pc, not with the state of its hardware. Look at the waveform. Try pressing some keys too, for added effect. [To those without an oscilloscope: (not sure if this works still), run the same program and turn on a regular radio receiver set to FM and place it near the pc. Then tune in to different frequencies until you get a certain 'sound' which you will know comes from the pc. Once you get that sound, LISTEN. If you can, record the sound with any sound recorder and place the recording into some graphic audio editor. Examine what you get and think for yourself.]

Try the same, if you can, on a C64 or maybe an Atari 2600 and note the difference. HUGE difference; no comparison even.
So if you can't get true steadiness even without an operating system running (ruining it) on top of your program, how could you get it at all?


The pc is not a real time system and it is not steady. It lags everywhere. 'Everything' with regard to steadiness on the pc must be a simulation or an approximation of steadiness, and it all goes right down to the hardware itself, but there's hope. We have 'acceptable-to-good' sound from pc's because the ear would never accept the abuse that's constantly going to our eyes and brains (from unnecessarily unsync'd video -- on purpose?). To this day I'm still not sure what the real agenda of the pc video card industry is, because one single bit would have made all the difference in the world, and I'm sure they must know this themselves quite well. Maybe it's also about money after all. If lawmakers knew full well of the 'video assault' we're being subjected to, pc video output as it is would be illegal.

In turn, while the C64, for example, was built with the hope of selling well and making some money anyway, of course, the underlying philosophy and design concepts used to make it were all based on game-making first and foremost (as far as I know), with every possible respect for the truth of the hardware and for the truth of video and sound. All their design decisions seem to have been made with these things well in mind. The results speak for themselves right to this day.

Me? I don't want to go back to the '80s. I want to make it better for myself with today's good improvements. The higher they must push clock speeds in order to run their high level languages and feel good about themselves, and the more memory space they must come up with in order to store their wasteful programs, the better that it is for me. My programs and my hardware will always run faster and they'll be smaller. They'll always be better and run better and smoother as a matter of simple math. It's just the facts, just how it is. If someone ever bothers to make GHz 6502's, I'll be there just for the fun of it.

I (used to) program hardware games, mostly unknown but nevertheless they were there.
Sometime during the '90s, when I realized that pc's were getting fast enough in terms of effective clock speed, I saw that I could base my games on it and still have professional output; with a bit of 'tweaking' done to hack the hardware against its lackings I was set. So that's how I was able to overcome the pc's blunders with some internal and external circuitry attached to it, going from something as simple as the parallel port and the vga port itself. In terms of perfect output and gameplay, there was no difference between my systems made this way and the hardware I'd designed before. That's what the oscilloscope said as well. I achieved those results because I 'forced' the pc hardware to work for me instead of having my game work 'along' such a hardware while dragging its design errors left and right. It wasn't pretty or innovative in tems of design, surely enough, and the motherboard had wires coming from it like you wouldn't believe, but it was cost-effective and a very fast way to make games that worked. The competition was none the wiser. Little did they know they had a little neighbor right next to their expensive machines running from a cheap pc clone made in taiwan or somewhere like that, and outperforming them all the time. Of course, soon afterwards they started to get rid of the parallel port, so I used parallel cards instead. When parallel cards got scarce I used the PCI bus. Now they're getting rid of both the PCI bus and the vga port, switching them for some serial idiocy. So now once again I'm considering designing my hardware from the ground up but with today's technology. The times. Just a little reference.

Please excuse any error in the text. Quick run.

jsii, I think you'll enjoy these essays a lot. (Others have seen me post these before, but I'll post again since you're new here.)

• Software Survivalism, by Samuel Falvo, one of our own (now rather inactive) members. (In spite of the name, it's about hardware too.) I would like to see this way of thinking become more popular and organized.
• Neo-Retro Computing, also by Samuel Falvo
• Low Fat Computing (A politically incorrect essay by Jeff Fox) He and Chuck Moore (inventor of Forth), taking an entirely different programming philosophy, plus Forth hardware and software, have improved the compactness and speed of code by factors of anywhere from 100 to 1000.

They're from the "Philosophy" section of my links page on my 6502 website.

_________________
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?

Can't wait to read'em.

Thank you, Garth.
I'll be checking your website as well.

Thanks, I enjoyed all of the articles. Great to know there are others who share these values / opinions.
The tone of these writings reflects the mood I was in when I started this project and wrote the initial thread in this post.

Every time another small victory is achieved on the Vulcan Hardware, I feel a little better about this hobby.
I actually work in a machine shop, so I get to hit the "bare metal" every day, and I feel sorry for those stuck in the programming or electronics industry today.
Seeing where things are at, I would instantly quit and switch careers if I was stuck in the bloated electronics / programming industry.
Wordpress, Rapberry Pi, USB, Windows10, IP Cores, Arduino Libraries, HDL Simulators, Protected media... shoot me now!!

Vulcan-74 is my reality check in today's bloated, Monsanto style World ... "yeah, I can still do that"!

Cheers!
Radical Brad

I'd hold on to that reality very strongly if I were you. Don't let go. Just make sure not to get stuck in the loop. I hope you don't have to learn for yourself what that means.

If you think of your work as 'hobby', that's where it rests.

Those in the 'software'/devices industry "feel sorry" for you, Brad (not really), and to them you're nothing more than someone stuck in the past with some archaic "dead" "language" ('assembly', of course, not to mention machine language and the rest). They seem convinced that they're the ones ahead in terms of technical excellence. I say it based on my observations about them.

Good work.

Garth, I read the articles and I went to your website. Very good material.

About the articles, what will I say? I could speak volumes, except that action is what's needed more, in my opinion.
Somebody better do something fast. I'm all ears. You guys here have a bunch of hardware, very good designs, I can see it. I don't mind a little custom programming if there's a good goal, so I'm listening.

About the website, very good website, thank you very much. Just how I like'em. Went through some of the links.
If I find a place in a design for one of your modules I'll consider purchasing one; just so you know.
Very good work and thanks for sharing. If I'm good for anything, let me know.

I'll try to be around. I like it here already.
Thanks again.

That should be excellent for packaging your creations! Building a breadboard is one thing, but I have found over the years that my packaging dreams are simply out of my reach without something like that.


I tell ya, I've come awfully close to quitting my job at times when the boss wanted stuff like Bluetooth. After looking into things, I just told him, "If that's what the job is going to involve from now on, then I'm not interested," and at that point I didn't care if he said, "Ok, good bye." Instead, he valued my ability to whip up circuits, especially analog, highly enough to change his plans so I'd stay. When the fun is gone, so am I; and there have definitely been times when I thought I'd rather stock shelves and push a broom or drive a street sweeper or something.


You've come to the right place.


Thankyou. There are a few more major features I want to add to the website, but they're all an incredible amount of work, and I'm a little worn out on writing, and I need to get back to building. I'm starting to build myself another workbench computer with more of everything than the current one has—memory, speed, portability, I/O, A/D and D/A channels and with more bits of precision, bigger display and keyboard, etc.. It's a huge job, and it's amazing how many details need to be ironed out before you can start building the main computer board itself. I'm going for a half-rack-width 3U VME card cage (although my pinouts and signals won't be VME-compliant).


Thanks. I occasionally get emails from someone wanting to sell their services to make my site look professional, or asking to buy advertising, something I don't want on my site. I want it super simple while still being as clear as possible. If I were selling insurance or something, then yes, I'd have to have the irrelevant pictures of smiling families in the park, the annoying Adobe Flash things, faded pictures behind the text that make it harder to read, and those extremely irritating viscosity effects!


Thankyou. With the price of PCBs coming down and down, it is becoming more realistic to offer more types of little modules, which I hope to do.


Be sure to see my article, "Assembly Language: Still Relevant Today."

_________________
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?