Jump to content

Scott Robison

Moderators
  • Posts

    824
  • Joined

  • Last visited

  • Days Won

    37

Everything posted by Scott Robison

  1. Exactly. Really, a CPU is not a computer either. It is but one component of a computer. A C=64 with a pristine 6510 but without a VIC II is a paperweight. Or a pair of 6526. Or the right number of RAM chips. I mean, they are fancy paperweights that do various forms of blinky lights or sounds or whatever depending on what is missing, but the computer is a complete collection of parts and interconnections between a number of components. I agree with the philosophy that it is nice to have a discrete component based system for a certain set of reasons. In like fashion, the MOnSter 6502 is a nice recreation of a MOS 6502 made from all "discrete" components. It would also be cool to see a 6502 made from all vacuum tubes. But some of these are impractical, even if they are cool and have other positive attributes. The beauty of an FPGA system is that, for a sufficiently large FPGA, it is possible to recreate all the individual components that go into a computer in a single chip. There is still more to do of course. You have to get input from the outside world into the FPGA through IO pins, and get output to the outside world through other IO pins. That has certain benefits and certain detriments, just like the other things listed above. And that is the entire world of engineering: Understanding what is possible and weighing the pros and the cons and coming up with the right solution for a given problem. If one wants to create a video system out of all discrete components because it "simply requires optimization" then I say, go create it! I was reading just yesterday about the C74 project which has as a goal to create an entire C64 out of 7400 series logic chips. Someone is "working" on the VIC II portion of that. I hope they succeed, it will be a sight to behold I'm sure. But it isn't "practical" for an intended mass produced system in this day and age. And that's okay, not everything has to be practical. But if you are hoping to build a computer that can be used by people, practical is a really good thing to strive for.
  2. That's a difficult question to answer exactly, but from what I can find via Google searches, you're looking at an up front cost of multiple tens of thousands of dollars, then a volume of at least 10k per year to bring the costs down to the sub $2 range per IC. It's not impossible but not practical for the expected scale of something like the X16. That all assumes some of the least expensive processes would be usable.
  3. With the solution above, I am assuming P is the complete VRAM address from $00000 to $1FFFF. The second line doesn't have to do the "OR INT(P/65536)" part if the address will always be $FFFF or smaller.
  4. Given a base address P I think what you want to replace the VPOKE with: POKE $9F25, PEEK($9F25) AND 254 : REM SELECT ADDR 0 POKE $9F22, %00010000 OR INT(P / 65536) : REM INCR 1 AND VRAM ADDR BIT 16 POKE $9F21, INT(P / 256) AND 255 : REM VRAM ADDR BITS 15:8 POKE $9F20, P AND 255 : REM VRAM ADDR BITS 7:0 REM NOW THE ADDR IS SETUP SO DO EVERYTHING AFTER VPOKE LINE...
  5. I haven't looked at reference material to ensure all the numbers are exactly correct, but that seems reasonable in theory.
  6. I agree you've been deliberate, and my comments were not directed any any particular person, just a general observation. Sorry if they came across differently, that was not my intent.
  7. I'm not an FPGA expert but you're on the right track. However, there are different physical limits on a PCB with discrete components than there are on an FPGA. When creating the 6502, there are more or less two types of uses for transistors in the CPU. One is as gates, the other is as so called "random logic". If we were to compare them to computer programming, gate based transistor logic is like structured programming. It is relatively easy to understand when you look at certain combinations of transistors that they create various types of gates: NOT (inverter), AND, OR, XOR, NAND, NOR XNOR. Other combinations though do not correspond to standardized gates, and those are the "random logic". It isn't truly "random" as in "random numbers" it just isn't as structured as the gate based transistors. You might call it "spaghetti code" of the integrated circuit world. You can do the same things (I think, generally speaking) with gates, but it might not be as efficient. It might require more transistors and take more time to process with gate based transistors vs random logic based transistors. FPGA is a field programmable GATE array. So that is one difference between what one might get when implementing a 6502 in an FPGA vs in silicon, as the FPGA primarily provides for gate based design work. Extending the definition beyond the CPU to a video subsystem: Given that there exists hardware description language for VERA, it could be implemented in discrete parts, but now you have to consider timing. With all the functionality in gates in the FPGA, which takes up millimeters of space, signals can propagate between gates orders of magnitude more quickly than they could on something the scale of a circuit board with traces between chips. Just the fact that they are further apart means things take longer. Then you also have more considerations of noise. More parts means more things to go wrong and more time to troubleshoot. In the end, the FPGA is the most cost effective way to create this system. I love the idea of a discrete parts board with a separate CPU and IO chips and all the good stuff, but not everyone is going to love that as much as just having something that works.
  8. I wouldn't send up a 90 year old, but if you want press, I guess you invite a big celebrity to go up on your rocket.
  9. When people focus on what David put in his first video, such as "no FPGA" and claim this is not in keeping with his dream, they seem to overlook the price aspect of that initial dream. We've all subsequently learned (for those who didn't know it previously) that some of those goals are mutually exclusive. You can either spend a lot more time, money, and other resources trying to build a discrete video subsystem that has all the bells and whistles that were desired (which completely destroys the cost) or you go FPGA (which is much more affordable) or you just throw up your hands and say "can't be done oh well". David showed X8 as being possible at an affordable price point but ultimately stated it wasn't enough like X16 on FB, so they're looking at something similar that will still get close to his originally desired price point. I big part of the motivation for this was "how can people get into retro computing at an affordable price". Here is a question for the community at large: What is better for the X16 ecosystem, a kit that only select people will be able to assemble, or a relatively inexpensive FPGA based solution that many more people can afford that won't involve assembly? While the former would be awesome to have (and I plan to buy it when it becomes available) there is far more potential buy in with the latter (which I also plan to buy when it is available). I think there is too much "what do I personally want" and not enough "what is best for adoption so there can be a vibrant community". There are still C64 games being sold today thanks to critical mass of adoption and not nearly as much if any software being released for the KIM. If one simply wants a retro computer to use on their own and aren't worried about a community, and a kit scratches that itch, fine. But if you want to be able to find software to run on it that you didn't write yourself, you're going to get a lot more options if the hardware is more accessible to a wider audience. In that respect, the kit is not unlike a KIM (inaccessible to all but the most hardcore fans) and the complete FPGA solution is the C64 (much more accessible and interesting to a much larger universe of potential users).
  10. I think most of those new posts are mainly by the community, not the team, so it is even less than that. Edit: I should have read everything first, I see this point was already made.
  11. This is the internet. You're being entirely too reasonable in your thinking. You should work on that.
  12. Not unreasonable desires. I think that the comments that happen on FB are far less of the "here is a big announcement" and more of the "oh, here is some throwaway information in a blurb" variety. When David felt he had a big announcement / information to share, he came here and made this post, and referred FB to here. I think part of the problem is that we have many people here dying for a crumb of information, so they latch onto the literal crumbs that appear on FB as life saving manna, when really they aren't "affirmative notifications of progress" but rather "oh, that thing didn't pan out so someone is looking into something similar but better but there is no substantive news on that front yet". I can't "defend" (nor can I "attack") how project leadership is handling communication with the community. For me personally, I look at it as "I would like to know more, as much as possible, but no one owes me more info; in like fashion, I do not 'owe' the project my allegiance". What each of us has to decide for ourselves at this point is "we know how this project is working; when do I reach the point that staying is no longer of value to me". It seems clear that to some people in this very long thread, they have reached or are reaching that point. It is a shame, but I can't blame them. For me personally, and maybe it's partially because I've been in the community for six months or so, I still believe that X16 will happen in one form or another, and I look forward to its eventual release. I felt the same way about MEGA65 and I was recently rewarded for my patience. I expect the same in this case. I'm only investing a little time in this at the moment. I've told David I'm more than happy to help out however I can. If there is a way for me to help the project in a more active capacity in the future, great. If not, I'll stay here and be a cheerleader in the meantime. Others may feel differently, and they have to go where they feel they should in this whole process. I might give up at some point, but I'm no where near that point at this time.
  13. I was telling my wife about this and said "obviously it is impractical for everyone to do this; ideally, the capsule recovery team does it, or at the very least the one who actually opens the hatch."
  14. Seems like there are better places for some of this discussion than this already too long thread. This thread is about what to do with the X8/X16 as they exist. It is not about philosophical discussions about how it should be done. At this point X8/X16 includes FPGA because a certain level of video capability and performance was desired, and that is the most cost effective way to realize the dream. Sometimes dreams evolve and plans change as new information and realities are realized. That's not a bad thing.
  15. I can agree with this just because of perception. The grave interpretation was I think what was being argued against, not that updates wouldn't be welcome. Just that I can understand why updates haven't been forthcoming.
  16. This. So much this. All the this. I'm 53. I missed certain eras of computing. I wonder if there was as much pushback from earlier generations against ASICs instead of all discrete components? Or if there was pushback against the transistor when it replaced the vacuum tube? It brings to mind the quote from (I think) Arthur C. Clarke that any sufficiently advanced technology is indistinguishable from magic. My corollary would be "to some people all magic is black magic and to be avoided."
  17. I haven't read anything that says "kit form is off the table". It would be a good idea though to first know that the kit works when properly assembled. That is the reason why we haven't seen a kit yet, because anything else is just sending people a random assortment of parts with a PCB.
  18. I rarely use my phone on the forum. If I did maybe I'd value tapatalk more. But the nag screens to invite me to use it turn me off of it.
  19. In the past I've setup a pristine virtual machine for scammers to log into and "fix" so ... I have no problem taking time to play out the long game. Today, however, I didn't have the desire to go to great lengths. Normally I do get a better reaction from them though.
  20. Thank you Lorin. Not being team members, it doesn't matter how much I, BruceMcF, or others make similar statements, we simply cannot fight the disinformation as effectively as you and others on the team can. I mean, it's not like anyone can truly stop disinformation / fake news. It takes on a life of its own. But I appreciate your effort.
  21. There are far more people who've done a better job than I, but a few years ago I uploaded a series of videos called "Messing with Scammers" to my YouTube channel. I generally didn't go seeking them out, but I'd take their calls, pretend to fall for whatever crap they threw at me, and just generally waste as much of their time as I could. I think my record was about 110 minutes. Even though I haven't produced any videos for 5 years now, I still mess with them when I have the opportunity. Just got off a phone call with one, in fact. {phone rings} Robot call: "This is Apple Support. We have noticed suspicious activity on your Apple device. Please press 1 to be connected to Apple support." Note: I do not own any Apple equipment. {presses 1} "Human" (I'm feeling charitable) agent: "Apple Support, how may I help you?" "I just received a call warning of some suspicious activity?" "Yes, our automated system called you. I see that there have been two attempts to make a purchase with your Apple ID. Have you been travelling?" "No." "According to our records, most of your activity comes from Utah." Note: Good job figuring out my area code meaning, scammer! "Yes, that is correct." "The two suspicious activities came from Nigeria. Have you travelled to Nigeria or do you know anyone from there?" "No. I get spam messages claiming to be from Nigeria, but I don't know anyone there." "There is a $1200 and a $2400 attempt to purchase iTunes gift card, have you attempted to order these?" "No, not at all!" "Okay, you will need to reset your password. Please open your Apple device and go to settings." {time passes} "Okay, I'm there." "Next you need to tap {something I don't remember}." {time passes} "Okay, done." "Do you see two transactions for $1200 & $2400?" "No, I don't see anything like that." "Did you tap {something I don't remember}?" "Yes, of course." "Okay sir, what do you see." Note: At this point the game is up; I have no experience with iPhone devices to bluff my way through what I should see at this point. "I don't see anything, because I actually don't own any Apple devices, I've just been trying to waste as much of your time as I could and" {click} Kind of disappointing. I was only able to waste 4 minutes including the robocall at the beginning, and he didn't react at all, just hung up on me. Oh well.
  22. While I agree it would be nice for people who want to use tapatalk to have that option, I appreciate not being suggested to use tapatalk every time I access the forum on my phone.
  23. Acme is a cross assembler, so the source code you write to feed into it uses ASCII (more or less from the 1967 standard that has been modified slightly over the years). The Commodore 8 bit line uses PETSCII (an extended form of ASCII 1963 standard that is similar to what we know as ASCII today yet different, and all the extensions on top of that). So !PET is used to convert the ASCII encoded source code into PETSCII encoded object code. If you are porting code to a Z80, likely using CP/M (though not necessarily), you won't want to convert ASCII to PETSCII for the main ASCII characters. Any extended ASCII that a platform might use is going to require a custom conversion. !SCR is used to convert the ASCII encoded source code into screen codes that can be written directly to screen memory, as they are not compatible with ASCII or PETSCII. Any Z80 based system with video hardware might use ASCII for its memory mapped video (if it has such a thing) or it might use something completely different. There is no universal way to say "this is how !SCR should be translated to another platform".
×
×
  • Create New...

Important Information

Please review our Terms of Use