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Bryan

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Everything posted by Bryan

  1. Just thinking here... There may be a way to get some crude alignment on 2 voices with AUDCTL, especially if you can base some pitches off the 15KHz clock. Load the intended pitch, but flip to the 1.8MHz clock until you want the wave to start. You'll get ultrasonic (silent) waves until you flip back and then the slow wave starts. EDIT: I guess that's no better than cramming a divisor of 0, though except that it would affect 2 voices at once. Although flipping to the fast clock would run out the timer on the current pitch quickly since you can't align anything until the counter expires.
  2. Just the datasheets, app notes and emulation info on old voice chips. Looking at the requirements. Well, I believe you can align a voice by: 1. knowing the cycles since Pokey was reset (using WSYNC alignment or maybe triggering an interrupt off a voice?) 2. cramming a short pitch value (perhaps at 0 volume) to delay the next square wave. Cycle counting would be needed, but at least locking to scan lines makes it deterministic. I've also thought about the sounds Alley Cat makes. It's possible there's enough poly sounds already in there that would be suitable for a crude robot voice if you could find them all.
  3. After reading old documentation on speech synthesis, I'm convinced that intelligible speech can be done on Pokey without the overhead of sampled phonemes. You need to identify the main frequency components and type of noise (f, s, t sounds) needed and change them at regular intervals through the phoneme. The poly sounds could be really good for getting basic combinations of frequencies too.
  4. Sometimes the drive spindle or clamping cone bearings have dried out. Note when testing the cone bearing that it won't spin freely unless it is pressed down into the spindle hub (when the door is closed).
  5. Anyone in Poland willing to help me buy something off Allegro?

  6. Hey everyone! I'm finally finished with the remodel and sale of my house and I'm in the process of moving and setting up a new electronics lab. Sorry I've been away so long!

    1. Show previous comments  2 more
    2. Bryan

      Bryan

      No, I'm staying nearby. We've got my wife's elderly parents to look after.

    3. doctorclu

      doctorclu

      Welcome back Bryan, you were missed!

    4. Stephen

      Stephen

      Great to hear you survived the move!  We kept the lights on here for you.

  7. Bryan

    Bryan

  8. I want to give everyone an update: I have been working full-time on renovating my house to sell. As many of you know, my wife and I spent 3 1/2 years in Costa Rica and I had a large freelance job lined up that I thought would provide income while we were there. Well, it kinda fizzled due to a lack of interest from the other party and when my wife and I moved back, we were deeply in debt. I bought a cheap fixer-upper house in Michigan so my wife could take care of her mother with advanced diabetes. At first, we were going to live here and slowly work off our debts, but with the rising real estate market combined with a generous offer to live cheaply with friends, it has become important to finish up my repairs and sell the house ASAP for a fresh start. To this end I've been living in a construction zone and maxing out my credit cards to get the work finished and I hope I'm in my final month of this gigantic task (this house was cute, but completely trashed in every way). I'm shipping out current orders as I can make the time, and I hope to resume development of future products as soon as I get my lab set up again somewhere else. I know I still have PMs to answer and I'll fill as many remaining orders as I can, but I'm not planning on ordering any more boards until next year. I just wanted to explain why I dropped out of sight for a little while. -Bryan
  9. Just found out what happened. Due to budget constraints, Rob Wyatt had to swipe the web server computer when setting up his office.
  10. I see you got the early backer commemorative t-shirt.
  11. Might I suggest an Indiegogo campaign to pay someone to keep the website online?
  12. I believe it saved an extra transistor per bit cell. With EPROMs, you're basically charging a small floating capacitor acting as the gate of a FET. With no charge present (erased cell), the FET conducts and this is represented by a 1. Once the gate is charged, the FET no longer conducts. UV light can excite the electrons enough that they tunnel through the barrier and discharge the gate (and, they'll discharge themselves naturally over the next 20-50 years).
  13. The AC mixes one or more sources into a single channel because mono output is used far more often in Atari systems than stereo. Two of them could be installed for stereo, but you could also wire in stereo audio directly from TIA and then use an AC to generate an alternate mono signal. To do this, follow the mod described here: http://atariage.com/forums/topic/199461-atari-2600-stereo-mod/?p=2545630 Then run left and right (before the output capacitors) into AC inputs A and B to mix them without affecting the stereo signal.
  14. Sure. An RCA connection is very common for audio. Or, are you asking if the AC board is necessary? It isn't, technically, but it greatly simplifies creating an output that mixes Pokey and SIO audio together (like tape loaders with music).
  15. I deleted my comment about a Rev A ROM. The Tech-Tip was actually talking about the computer OS even though it was included in the 810 FSM. It would be interesting to see if there ever was a Rev A released. Maybe in a prototype drive. One thing is clear from the Tech-Tips, Atari had a lot of problems getting this thing to work right at first.
  16. Here's a (rough) picture of the ROM in the schematic. Notice how they labeled the chip selects on the left as active low, but pulled them high? They are indeed active high, but that makes them incompatible with any 23 or 25 series EPROM I know of. Mask ROMs often have optional inverters on these pins allowing you to pick the polarity. This is how they made all those 2600 games respond to A12 properly. -Bry
  17. Yeah, sorry. That was confusing. I was just bringing up why it doesn't do graphics. I had a 1025 back in the day and I was kinda pissed when I realized it had no graphics mode.
  18. From what I've heard, the Okidata equivalent printer was text-only as well. It would be a fun hacking project to put a gfx mode into the firmware. You might need to add a little RAM too.
  19. It may depend on the brand of RAM as well.
  20. The 5200 is a mess. The 16Kx1 DRAM pulls a LOT of power during refresh and the power conditioning on the UAV apparently isn't enough to overcome it. I'm planning on coming up with some board mods to further isolate the DRAM from the supply.
  21. Hi everyone. I've been pulled away from my Atari projects for a little bit, so I've ordered a small run of UAV Rev D boards to keep them available until I have more time. The available options are currently: Basic $22 Plug-In $25 Kit $25 XEL $25 5200 low-profile build $25 I'm getting caught up with PMs as well so let me know if I've forgotten anyone.
  22. Use a quality Type I. Other formulations will be a mismatch and their main advantages (better response, dynamic range, etc...) don't matter in this application. Tape shouldn't be considered permanent and a digital copy should be made (and saved in a lossless format) as well. Something like the Maxell UR, Sony HF or TDK D range should be fine.
  23. So... your first post is a necrobump of a thread that's been dormant for 8 years?
  24. No. The channels are mixed and sent as normal mono audio. Combat uses one TIA channel per tank because, well, that's how you'd probably write the game anyway.
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