Jump to content


  • Content Count

  • Joined

  • Last visited

Community Reputation

84 Excellent

About rmzalbar

  • Rank
    Chopper Commander

Recent Profile Visitors

2,088 profile views
  1. WELL. I figured this out. Mine is a 4-switch with no 4050 so I manually wired it. I had 3 wires swapped around, 2 luma and 1 sync! I don't know how I made a mistake like that, or why I didn't find it quickly. I must have been looking at an erroneous pinout or something of the sort back then, and I evidently didn't look at the signals live, but sure enough when I put the oscilloscope on the sync input I saw a luma pattern. D'oh!! The luma and sync are TTL signals that then go through different voltage dividers (on the Atari on the way to the modulator, but also on the UAV board in a similar way) to set their relative levels, so that 3 separate TTL luma signals can be mixed in binary fashion to make several luma levels and you get a proper sync level. They were going through the wrong resistor networks so they were at the wrong levels! The sync pulse was too small, causing unstable sync. On bright screens or games that flash the screen brightly, it would lose sync altogether.
  2. I am disappointed. I wanted in on this class-action. I always want in on class actions, whatever they're about, really. I.. I like that.
  3. I'm not a fan of Facebook's influence in the world, but I don't feel any particular emotions toward the platform itself. I use it in a very directly utilitarian way: I belong to the old computer groups and use it for that purpose only. I don't use it for anything else, my bookmark goes straight to the groups interface. No doomscrolling, no stalking friends, no anything except old computer nerds. I'm okay with it on that basis.
  4. I just wanted to add my congratulations on a great port of this great game. I also want to say Thanks! for permitting it to run under NTSC. The PAL divide can be really brutal to us Americans at times.
  5. The Last Ninja series had some very nice pixel art and a banger of a soundtrack (on the C64 at least) but the playability was.. not good. I've seen this to be a thing with European gaming tastes in general during that era; style above substance, and if style is all you have we'll just take it anyway. Compare nearly any US publishers (Accolade, Activision, Epyx, DataSoft, Electronic Arts, Microprose, Synapse, Broderbund, HesWare, SSI, Origin, Sierra, Muse, Lucasfilm, Infocom, Mindscape, etc.. ..and people ask why I don't convert all my machines to PAL..😝) who consistently turned out quality, QUALITY titles against, well, just about everything else. It's a real shame, because I would love to see a fusion of talents, east and west, in an alternate universe. At least we seem to be getting that with homebrew and smallscale retro releases these days! Somehow, the ZX Spectrum seemed to have largely avoided these issues, probably because playability was much easier to get on that system than shiny glitter. The ZX is my favorite eurogaming experience.
  6. I have a 600XL, an 800XL and a 1200XL, and ended up being very fortunate that all three of them were fully socketed, and on top of that the 600XL(AWC) and 800XL(Alps) both had mechanical keyboards. Not a hint of trouble with any of them, and only had one bad key.. and it was just a cracked solder joint. Atari built them good enough. The 1200XL of course needed a keyboard matrix refresh.
  7. That's exactly how Ghostbusters copy protection works: There's an intentional error on one of the tracks that the game checks for while loading. Disk copy programs wouldn't copy the error, so the copies would refuse to load. The disk drive responds to an error with a track zero seek - that's the noise you hear. It's harmless for nearly all drives (some really early model 1541 drive were known to get bumped out of alignment over time.) This was common only in the earliest days of copy protection; disk copy tools could soon reproduce those errors properly while copying, and so the game publishers had to move on to more sophisticated methods that didn't cause read errors. I have a copy of Ghostbusters that runs correctly on both PAL and NTSC machines, and has that protection patched out. It's a combination of a specific original disk image with a Maverick parameter applied. Could provide .G64 of it but you'd need some way to remaster it to a disk, such as a Zoomfloppy setup. Another early Activision title I have that does the head bump-o-rama: Zone Ranger.
  8. What happens if you have an XL and accidentally set this? Can you recover from that or is it JTAG time?
  9. I would just like to thank Phaeron for creating a8rawconv. I just used it for the first time to write an image back to a real disk, a copy-protected Fort Apocalypse atx, with SCP hardware and a 96-tpi drive. Boots up on my real Atari just fine (once I set the 1050 to unHappy.) Is it an impractical way to load Fort Apocalyse? Definitely. Do I love putting the disk in the drive, powering on, and listening to it boot up just like I did 35 years ago? YOU BET!!
  10. Not long after COVID hit, I had to put everything in storage and move into a tiny place. Nearly all of my fun projects got shelved. I recently took my Atari crates out though so I may get to it soon. I think when I last looked at it, I found the logic for the original happy wasn't accessible in the Atarimax setup and that I possibly couldn't do better than Binarygeek, but I hadn't written it off yet.
  11. Very nice 600XL. I acquired one early in the year, and finally got around to giving it a similar treatment over the last week. Yours came out very clean, I was never confident enough to touch the aluminum on any of mine. Mine has the same AWC keyboard - it's pretty decent, doesn't block if you hit the keys off-center the way the ALPS keyboard on my 800XL somewhat does. Mine had a cracked solder joint on the "M" key. I've been fortunate that the two XL machines I got both happened to come with mechanical keyboards The keys just work and no worries about membranes, but I shudder to think what I'll do if any of the switches ever need to be replaced. I game mine the U1MB and the Super Video 2.1 treatment. I used FJCs 3-wire 64k mod instead of the Lotharek one. I removed the battery holder from the underside of the U1MB to allow me to mount it about 5mm closer to the motherboard to take some pressure off the keyboard ribbon. I intend to modify and reinstall the shield again at a later point.
  12. Looks like after Super Video 2.1, the chroma and luma communicate through a three-component series of 75R, .001uf, 75R, combo. The capacitor and resistor form an RC filter and probably filters (I suppose) the luma out of the chroma. Worth a try? This is from 800XL SV 2.1 (the pre-Super Video schematic also showed that series to combine the luma and chroma, but of course there's no chroma to pin 5.) Also note the composite-disable switch I mentioned in that string. You likely won't have 75R resistors, but you can just use a single 150R and capacitor in series. The only reason for the order of the three is to set the composite output impedance, which is in the middle of the series, to 75 ohms.
  13. I use a vintage flippy puncher, but since I've started remastering flippy disks from images (with inket repro labels even), I installed into a 1050 and a 1541 a write-protect sensor disable switch so I can master flipsides without punching them at all. When I was a kid.. I used a robust steel paper hole punch, using another disk for reference. Not as pretty but works fine.
  14. It doesn't happen if you use the optional composite video disable switch that's part of the Super Video 2.1 mod. At least, not on any of my three machines. If I leave the composite enabled, it does look like yours. This can only be from luma leaking back into chroma from where they are combined to make the composite. So if you want to cause it on purpose, just tie the two together with a large value resistor at the output of the UAV. You may need to experiment with resistor size.
  15. SLA printers have become cheap enough at last. I'd bet replacements printed with one might be good enough, if the resin itself proves tough enough.
  • Create New...