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Scott Robison

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Everything posted by Scott Robison

  1. Now I'm afraid to go back and see how much I contributed to this discussion ...
  2. I finally got around to installing BMCBM (okay, it's called BMC64, but I think it should be rebranded to BMCBM given that it includes five different machines in one package). It booted up to the classic C64 in PAL mode. I switched to NTSC (since I'm in NTSC land) and C128 mode and I finally have a C128 again. I've done very little with it, mind you, but at least I can see it boot and can write little programs on it, as well as switch to C64 mode to play my games that were never ported to C128. Now I just have to dig around more into the settings to figure out what I can and can't do relative to a full blown Vice installation on Windows.
  3. One thing that I think might be better for an API (esp on 6502) would be to pass a pointer to a structure instead of a bunch of individual values.
  4. There is a lot to be said for source code quality and convenience of using bit fields, but remember that the compiler will be doing packing and unpacking of the fields just like you would have to. That's not a reason to avoid using that feature, but it isn't likely to improve performance (assuming the same technique is used in manually written code as is used in compiler generated code).
  5. That's a good point. I had C= 64 stuck in my head where the CPU had to share time with the VIC, but that need not be the case for a new layout. In that case, communication between CPUs could be as simple as reserving a byte with flags. One CPU sets a particular bit to "interrupt" the other CPU, and the other clears the bit to acknowledge the interrupt. Eight bits allows four bidirectional channels or whatever combination is desired. More memory could be reserved for message passing depending on the amount of data needed. Seems too simple.
  6. The hardest part of a dual processor 6502 is going to be communication between the two if they try to share memory. I guess dual port RAM could help alleviate that, though I'm thinking a "better" way (in as much as it makes sense to create a multi 6502 based system) would be for each CPU to have its own 64K of RAM with DMA circuitry sitting between the two. Then when one CPU wanted the other to take up a task, it could use DMA to quickly copy RAM from one RAM bank to the other and signal it to run.
  7. Exactly! I once computed the number of disks that would be required to emulate a Windows 10 system on a C= 64 with 1541. Let's see, the computer I'm using right now, assuming we could even fit a CPU emulation in a C= 64 without having to swap programs in and out of the address space, would need 16 GiB for RAM and 951 GB for the SSD. So let's call that 902 GiB. I can store 166 KiB on a 1541 based on 664 blocks free (I'll just assume I read and write individual blocks rather than use files which would consume two extra bytes per block, and any overhead I can squeeze into otherwise unused directory sectors). So I'll need almost 5.7 million floppies just to emulate the RAM and SSD. Undoubtedly I'd need more to emulate other aspects of the system such as video RAM, CPU cache, etc. I wonder where I can find 5.7 M new old stock floppies? Or we could go really old school and use tapes!
  8. You are in my town! I don't mean I live there, just that my name is Scott Dale ... #haha Welcome...
  9. Now I want to write a Windows 10 emulator in Commander X16 BASIC. #haha
  10. Looks like I picked the wrong week to stop drinking. Makes sense, sorry for the noise.
  11. Wait, did you type "need" when you meant I "read" a byte? I didn't use the emulator to read the ROM, I just looked at bank 3 instead of bank 0, which would be GEOS bank, not BASIC. But as I later wrote, I finally realized my mistake. I used hexdump on the rom.bin file and my mind said offset FFF8 would be the signature location because I failed to take into account the fact that each rom bank is only 16K, not the entire 64K address space. I can be dense sometimes especially when I have other things on my mind. Also: I was looking at a home built R39 I built on April 25, just in case there has been drift since then as I've not pulled any updates since then, more or less.
  12. I'm not sure I understand how one relates to the other. My only meaning was "the signature includes $FFF8 but starts at $FFF6". That is true regardless of what bytes exist in any other ROM bank.
  13. DOH! I didn't think about the rom being 16K pages. I was looking for the bytes at the byte offset, which would have put it in bank 3. Though: It still doesn't start at $FFF8, hence part of my confusion. But the bigger issue was my duh me moment expecting to see file offsets as addresses.
  14. I looked at the rom.bin image and didn't see the signature at that offset.
  15. I'm assuming it is related to Michael Steil (aka mist) who is working on the kernal. There is a four byte signature in the source code, though I don't find it at $FFF8.
  16. I work for a government contractor. I'm a software guy, but we do plenty of specialized hardware in relatively low volume. Just chiming in with "hardware shortages in the supply chain are real" ... I think I can safely say that much without getting in trouble.
  17. True. Both were amazing, and even though Opportunity outlasted Spirit by a significant margin, it is impressive everything that was done for what were supposed to be 90 sol missions...
  18. Whenever I think of personification of machines (a chip being a small electronic machine), two things come to mind: Enterprise (particularly from ST3 when she exploded) and the Spirit Martian rover (https://www.explainxkcd.com/wiki/index.php/695:_Spirit). I rather liked the alternative versions fans created. No, I didn't cry at either of those, and you can't prove otherwise.
  19. And Bender! Head canon: With all the issues found with advanced CPU techniques, bugs in CPUs, security issues due to inter-core spying, etc etc etc, they decided to go to the best CPU that would be known secure where any defects were well documented. Yeah, that's it.
  20. I've played with my new The C64. It's not bad. Either the lag on the USB joystick makes games I used to play harder, or my age. But I don't feel older most of the time, so it must be the hardware.
  21. That would be nice, but I think it would be significantly more complicated than a function that simply returns the address of a variable without extending the syntax. But I've never dug too deep into the implementation details of the interpreter, really just enough to write my basic preprocessor to depend on the line crunch code.
  22. Or at least add a POINTER function (I'm assuming it hasn't already been added). That would be useful to BASIC programmers.
  23. I'd love to teach kids on something akin to the X16. Of course, I teach a Python class, so that's going to be a strike against it right there for my particular curriculum. There are many computer science concepts that could be taught via an X16. I plan to use the Commodore 16 (the one remaining true 8-bit computer I have) as a learning aid early in the semester before we get deep into Python. I also plan to bring in a PC mainboard and a raspberry pi. It is not important that they be functional to discuss some of the history / theory. If I had an X16, I'd gladly take it into the classroom and show it as a tool to aid comprehension, but neither I nor my school would have the resources to purchase 20 to 25 units. Now, the original call to arms doesn't advocate necessarily for an entire course built around the X16, so finding ways to fit it (or other retro technology) isn't an impossible task. The tall order is finding the money to get enough into schools in a world where free software tools exist for javascript and python and a variety of other languages that run on commodity computers that already exist in the schools when trying to teach software and logic, and those will probably run on anything they have at home. The skills developed from an X16 (or C64 or Apple II or insert retro platform of choice) are immensely valuable! But so are the skills picked up from modern hardware. I think that something like the X16 or Ben Eater's project could have even more value in electronics and hardware oriented classes, but based on my experience, most people trained in hardware wind up working software, because that is where most of the demand is. I've said before I'd love to be wrong about the feasibility, and I'm going to participate to see what can be come up with. I just have my gut instinct of how likely this is, and I'm not in favor of pushing the boulder up too steep of a hill. A slight incline, perhaps...
  24. I understand. I wound up paying $173 including shipping (if I rationalize things by spreading the total shipping cost across the five items I bought). That was a bit more than I wanted to spend as I was hoping to buy it at list price or better on Amazon with free prime shipping, but that hasn't worked out so well. But considering all the other options I've found were $225 or more plus shipping, I decided to indulge myself. What I really need are more hours in the day to do everything I want. As for the Star Trek parody skit ... I just happened upon that on some cable channel one day and thanks to DVR, I was able to plug in a capture device and rip it. I couldn't find it anywhere on YouTube, so I took the chance of a copyright strike and uploaded it. Other sketches I'm aware of I had seen on YouTube, but not the one I posted. One of these days I'll get back to recording YouTube content regularly. Today is just not that day.
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