Jump to content

elmer

Members
  • Content Count

    224
  • Joined

  • Last visited

Community Reputation

474 Excellent

About elmer

  • Rank
    Chopper Commander

Profile Information

  • Gender
    Male

Recent Profile Visitors

3,633 profile views
  1. OK, thanks, I didn't realize that.
  2. The computer SALT and Super SALT carts are still available new from BEST Electronics ... they're not particularly expensive.
  3. Thanks, yes I read that thread recently. I don't want to keep on polluting this thread with digressions, so I'll start up a new thread to talk about this stuff.
  4. Both compilers are direct descendants of Ron Cain's Small C, and so only really offer peephole optimization, rather than the more-sophisticated optimizations that modern compilers can do. CC65 has had *much* more work put into its peephole optimizer than has gone into HuC's peephole optimizer, and so it will generally produce better code than HuC. That doesn't mean that HuC can never do better, just that it has had far less development hours put into it. CC65's developers have also put a lot of time into adding stuff to the compiler so that it can compile relatively-modern C code, which has never been a goal for HuC. HuC is much more like a C-syntax version of Action! ... it offers a lot of built-in functionality and library functionality that programmers can use for making games. For instance, this Kickstarted (and released) game was developed with HuC ... Anyway, the current version of HuC relies on the extra instructions in the 65C02/HuC6280, and so it's not usable on the Atari. I've been toying with the idea of doing a major overhaul on HuC's code-generation, and quite-by-accident, I found that what I'm thinking of doing would actually work just as well on the original NMOS 6502 that's in the Atari. Which is why I'm here, rekindling my old love of the Atari 800, and trying to decide if it's worth my time to try to make the next big version of HuC usable for Atari development.
  5. The HuC6280 copied that read-calculate-write mode from the original 1984 Mitsubishi 740, but unfortunately, only with the ADC, AND, ORA and EOR instructions, and not the SBC, LDA and CMP instructions. I've had a hard time finding a practical use for the capability in my code. I had thought of using the instructions to help with math on a software-stack in zero-page, but they didn't seem to help much. If anyone has a better idea for using that capability, then I'd love to hear it.
  6. It's hard to understand the HuC6280 in isolation, because it's part of a completely custom-designed integrated 3 chip solution for a video-game console/computer (with the HuC6270 VDC and HuC6260 VCE). The HuC6280 is a complete re-implementation of the 65C02 architecture that was never designed as a 6502 replacement/upgrade, so you can't easily compare how it operates to any of the original NMOS 6502 variants, or to WDC's 65C802/65C816. For instance, it has a single 21.477MHz clock input (with internal dividers down to 1.79MHz & 7.16MHz), built-in 2MB memory manager (eight 8KB pages in the 6502's 64KB address space), block move instructions with 1MB/s transfer rate, other new instructions that make programming more pleasant, plus built-in 6 channel wavelet-based sound chip. One of its big hardware improvements was that the memory accesses are full-cycle, so it runs the same 120ns speed RAM as the SNES, but it does a read/write cycle at 7.16MHz per byte access, instead of the SNES's 2.68MHz per byte access. From an assembly-language programmer's POV, it's as-fast-or-faster (in practical usage) than the 65C816 in the SNES and Apple IIgs ... you just don't get the 16-bit CPU registers, or the stack addressing. I worked on both the SNES and Megadrive in the 1990s, and have no desire to work on either of those architectures ever again ... whereas the PC Engine is an absolute joy to program (I'm the current maintainer of HuC, the PCE's equivalent to CC65). P.S. While the PC Engine / TurboGrafx was a spectacular failure in the USA, and was never officially marketed or sold anywhere else but its home market of Japan. It's worth noting that it outsold the Megadrive in Japan, and has hundreds of high-quality titles that most Western gamers aren't aware of. P.P.S. While the marketing folks, and gamers too, thought that the "16-Bit" generation was in reference to the CPU, developers and hardware folks at the time knew that it was in reference to the transition of the video chips from 8-bit data bus bandwidth, to 16-bit data bus bandwidth, allowing the shift from 2-bits-per-pixel (4 color) to 4-bits-per-pixel (16-color) at the same resolution. Anyway ... back to the Atari, my other favorite machine.
  7. Hello, cousin! I recently bought a 1200XL (with mostly dead keyboard), PSU & BASIC locally off craigslist. 83S DA 49382 173 Looks like I'll need a new mylar, but I'm currently waiting for an AV cable & SIO2PC to see if I can run some tests first (the ROM's self-test won't execute because the START key is dead).
  8. Back 1988/1989 they were still horribly expensive. Even the cheapest "cost-reduced" SCSI CD-ROM drive that NEC repurposed for the PC Engine was still well over Atari's $500 price limit ... IMHO, it wouldn't have made a blind bit of difference in the ST-vs-Amiga wars of the time. As soon as the Amiga 500 came out and dropped to close to the ST's price, the ST was pretty-much doomed. Anyway, sorry for (temporarily) hijacking the thread ... The only comment that I have to add to the original topic is that both were good machines, and the C64 definitely had some advantages when it came to games. But it's not a machine that I have ever wanted to own. As far as I'm concerned, the Atari is a far more elegant and high-quality design ... for its time.
  9. Thanks! That was enough to do a search and find out that it was mentioned in September 1985's Creative Computing, with a follow-up in April 1988's ST Log. Interesting ... so only the year after Denon & Sony had shown the first CD-ROM technology, and two+ years before the Yellow Book standard was published. So back in the tech-demo days of CD-ROMs, and well before the drive prices came down enough that Atari would have been in the position to really make a consumer-product out of one.
  10. After commenting on one of the Atari programming threads here, I decided that it might be time to rekindle my old love for the Atari 8-bits, and my long-gone Atari 800 ... so I just bought a 1200XL, and have been reading threads here to catch up on the current state of the Atari world. I'm kinda sorry to necrobump this thread again, particularly for such an old post ... but can anyone point me towards where I can find out more about this Atari demonstration of CD-ROM tech? My understanding of things was that NEC (PC Engine) and Fujitsu (FM-Towns) were the first major companies to seriously use CD-ROM tech, and I'd love to know when/what Atari were planning.
  11. It's really cool that you're downclocking like that rather than running at 20MHz (or 48MHz) ... but don't forget to take into account that the modern CPUs are 3..4 times more-efficient in terms of cycles-per-instruction compared to the original Z80 or Z8000 (or M68000). For instance ... add ix,bc Z80: 15 eZ80: 2 bit 3,(IX+n) Z80: 20 eZ80: 5 inc de Z80: 6 eZ80: 1 inc (hl) Z80: 11 eZ80: 4 inc (ix+d) Z80: 23 eZ80: 6 pop bc Z80: 10 eZ80: 3 At-the-end-of-the-day, you're still in the ballpark, and doing a great job ... which is why I'm taking such an interest in what you're doing.
  12. I get that your heart-and-mind are set on the "Cartridge Console" experience, and as the project's creator, you should just do what works for you. For me, the 1980s and 1990s "Happy Times" experience was the openness of the Home Computer gaming experience ... with floppy disks and tapes, and only-rarely cartridges. An SD card is just a "retro inspired" floppy disk. It is no more anachronistic than your use of modern CPUs and memory, that run dozens of times faster than the hardware that was actually available to designers back in those days. I'd be rather surprised if you're not including at-least 256KB of RAM on the system, which is all that you'd really need to recreate that experience ... but more RAM is always nice. It's not up to me to try to change your mind ... this is your baby, and I don't think that I'm really your main target-market, just a very-interested observer. If I like what you've created, then I'll choose whether to buy/develop for it. As for assembly language ... well, taking advantage of the extra features that Zilog put into the eZ80, and having a chance to finally work on the Z8000 architecture (ZNEO), are basically the attractions of what you're creating (from this programmer's perspective).
  13. Thank you for the clarification. I'm afraid that that almost-certainly puts it outside my particular area of interest as a developer, but I wish you all the best!
  14. You're making it all sound very interesting! Hmmm ... "a super orthogonal instruction set" ... OK, so you've dropped the idea of putting a 68000 in there, and I'm going to guess that you have probably gone with the ZNEO, since I don't think that there are many other 16-bit CPUs available these days. I do hope that you're going to have an SD card interface/socket on the board, too. Not only would that give you an easy place to store hiscores and other persistant information, it would also open the system up into becoming a modern CP/M computer ... like a modern ADAM.
×
×
  • Create New...