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About R.Cade

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  • Birthday 05/19/1971

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    Augusta, Georgia, USA
  • Interests
    Programming, Classic Computer Restorarion, Game Collecting.
  1. OK, now I found a conflict. The original "Atari 8-Bit FAQ" conflicts with the 7b/8b refresh story. http://www.atari800xl.eu/faq/atari-8bit-faq-us-letter-format.pdf "The ANTIC chip also generates DMA addresses for the (entirely automatic) refresh of on-board dynamic memory RAM (DRAM). ANTIC versions C012296/ C014887 use an 8 bit refresh cycle counter, supporting DRAM chips including those requiring 128 cycle/2ms or 256 cycle/4ms refresh (standard 16KiB and 64KiB DRAM chips). The C021697/C021698 ANTIC versions use a 9 bit refresh cycle counter, supporting additional DRAM chips that require more refresh cycles (standard 256KiB DRAM chips)." However, later in the exact same document: "FREDDIE -- 800XL("800XLF" and SECAM),XE(all):C061922/C061991 ======= According to Atari's design specification (C061922), the "Freddie RAM" Memory Control Unit (MCU) is a custom LSI chip providing dynamic RAM (DRAM) control functions. It replaces a number of small-scale integration (SSI) and mediumscale integration (MSI) transistor-transistor logic (TTL) parts, including a custom delay line. FREDDIE multiplexes 16-bit RAM addresses from the processor bus into 8-bit row and 8-bit column addresses for direct use in the DRAM, and it generates row and column DRAM address timing strobes. Any functional difference between the C061922 and C061991 FREDDIE versions is not well established. It is theorized that the original C061922 was designed to work with the earlier C012296/C014887 ANTIC versions with 7 bit DRAM refresh address counter for 128 row addresses, while the later C061991 also supports an 8 bit counter for 256 row addresses as generated by the later Atari 8 bit computers. Both versions carry the 1983 copyright date." So which is the real story? Or am I misunderstanding...
  2. Thanks - I will order the older one since they are on eBay for $4 at the moment. Hopefully that will work in the 600XL (with just the 64k upgrade) and I'll leave the newer one in the 130xe. I'm glad I didn't try the ANTIC from my 400, as that probably wouldn't have worked and caused me to socket the GTIA, which also would not have fixed it, and I would have been stuck. EDIT: Bah, the 4464 needs 8-bit refresh, so that will not work. Oh well...
  3. Somehow I beat the odds. I socketed the ANTIC first, and replacing that solved it. Anyone have a spare to sell? NTSC C021697 (-31 was in it, my 600XL temporary transplant donor has -11) I see someone is selling ANTIC out of 5200's on eBay, but it is a different part number. They are selling C012296D... I assume that will not work?
  4. I would say the distortion looks kind of like tearing or rolling at times, but it's not a loss of sync on the monitor... I'll make a video of it this evening for the curious.
  5. Hello friends, I received a couple of 130xe's in a trade recently. The first one I was able to find 3 bad RAM chips through piggybacking, so it is back up and running. The second one has these symptoms: The screen comes up with random flashing/rapidly changing things on the screen. The computer is "running blind" meaning it loads from disk, runs programs, I can hear the sound and type. The things on the screen do change based on what the computer is running. Mostly color changes I can tell... (blue BASIC screen, etc.) It's not bad RAM. I have swapped the banks and no change in behavior, and again the machine runs blind. Is this more likely the ANTIC or GTIA? Neither are socketed, and I may just go ahead and socket both while I am in there. Just trying to get an idea which it might be.
  6. What an ass clown... It ended and new auction created. eBay of course lists that as "sold" but it isn't... they do that for all buy it now auctions.
  7. Pretty sure Moore's law already hit the wall in 2012. Instead of getting faster CPU cores, we now just get multiple cores and "power savings" and have to make up for it with software solutions. Single thread performance has not grown a substantial amount for several CPU generations. http://www.cpubenchmark.net/singleThread.html I thought I read where silicon maxes out around 4-5GHz and we need some new technology to keep it going much beyond minimal advances now. Maybe there is more work in the GPU side of things now, but I don't keep up with that...
  8. I'd be on the fence also. It's definitely the very top end of the scale if it's stock (no accelerator). At least in my part of the country and local sale, it's a little high.
  9. I apologize if it has been asked before- I didn't go through this whole thread. In the old system, whenever I viewed unread posts/threads, it used to show the list of threads themselves with unread messages. Now, it only shows the messages themselves. I've played with it a little, but couldn't figure it out. Is there a way to create a view like the old way? If not, I will adapt... just asking. EDIT: Nevermind - figured it out. "Condensed" View looks like the old one.
  10. It's just a bench power supply with an Apple sticker on it. I've seen lots of cars with Apple stickers, but it doesn't make them an Apple product either...
  11. Something is causing the color killer to not engage properly. The older revision of Apple II board you have, the worse this usually is...
  12. It's bus noise. Mine get worse or move around during high memory or CPU usage. I have a couple 800's and a few 600's and I see these on some more than others with composite mods. Many things can introduce it but I notice it most on certain machines as soon as I replace the OS ROM with an EPROM. It can be toned down by adding filter capacitors from 5v to ground on it, or swapping with another EPROM. The same can be accomplished by filtering other parts of the board (especially around the video section) the same way.
  13. It was never used except for a very few games, and the hacking community. If you find one in the wild, it will be setup for HDLoader, 99.9% of the time.
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