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Nezgar

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  1. You can use a potentiometer on top of or instead of the existing resistors to find a new resistor value that registers, and then install replacement resistors similar to that value. Basically, I think as time goes on the resistance will increase in the conductivity between the mylar and the conductive material in the keys over time, so this hack just reduces the resistance in the power going to those keys, to help increase the amount that makes it through to a level the GTIA can detect again. I posted about me doing that in a past thread a few years ago. I may go dig that up again later if I remember. Edit: here's my post on that. In hindsight, I could have just replaced the doubled-up resistors with a single resistor of a reduced resistance... https://forums.atariage.com/topic/142703-xe-xl-keyboard-troubles/?do=findComment&comment=4362178 Edit 2: Also thinking... since these resistors connect to ground, I guess the result is increased pulldown to ground with reduced resistance, not increased pullup.
  2. Convert 155 in ATASCII to CRLF (ctrl-M, ctrl-J) in ASCII. I recall RespeQt can do the conversion automatically if you drag the file in/out of an ATR image with text translation mode enabled in the file browser.
  3. 400, 800, 810, 1050 and a few others need 9V AC output at various minimum amperages. Your linked adapter outputs 9V DC, not AC. Youll have to search a bit more for one with AC output - they are usually bigger bricks. With that said, because of the simple transformer circuit of AC stepdown transformers, the original bricks are usually perfectly safe to keep using if that's your concern. Edit: Also, you need a barrel connector size of 5.5mm outer, 2.5mm inner. Watch out for the more common 2.1mm inner barrell size connectors nowadays.
  4. If its a "lazer" it would function as a rev 1 happy 1050 (no corrupted single density ultraspeed writes, unbuffered) and not exhibit those symptoms like the more common rev 2. Its been a while to remember but if you start the genuine happy 7.x diagnostics software, see if the ROM test results in "Pass" or "PASS" - as that differentiates V1 or V2. (Or "FAIL" if the rom has been modified and checksum matches neither). Lazer had a modified utility disk to pass on its own modified rom...
  5. I guess that may toggle the happy ROM's unbuffered mode, which is not the same as "unhappy" mode, and not the same as switching the whole ROM to the Stock 1050 ROM, which the above switch does.
  6. There is a single wire coming off that Happy PCB that supplies +5V/Vcc. The other two wires go to the +5V/Vcc pins of the ROM on the Happy PCB, and a ROM still sitting in U10 on the main board underneath. This is attached to a 3-pin 2-position switch (SPDT on-on) on the faceplate to switch between "Happy" mode and "Stock 1050" mode. Of course this should only be done with the drive off. Nice simple hack mod actually. So centre pin of the switch goes to the +5V/Vcc from happy PCB, then the outer 2 pins of the switch go to Vcc of each ROM.
  7. Rescue on Fractalus (turn up the bass 😁) .. And the engine takeoff uses a pokey 16-bit pitch register for the very smooth high-pitched increasing whine.
  8. At the other end of that arm circled in the pic is where the spring is attached. That end has a bend down that drags against another metal surface. There may be enough drag there that a little push will "encourage" the mechanism to eject. If that works, a little 3-in-1 / sewing machine oil applied with a q-tip along the surface where it touches may help reduce that friction. I've also found sometimes that bending that rear bend a little inwards or outwards can help... will take some fiddling.
  9. Based on this I'd say your CPU/6507 socket is good, and your ROM socket has an issue. The happy board has the ROM onboard along with the CPU. While replacing your ROM socket would be the prudent action, you could try inserting a 24 pin machine-pin socket into the existing socket, and then the ROM into that. This may improve contact if the stock single wipe contacts have been depressed too far, etc. The happy boards also use machine pins, which may help improve contact in your CPU socket. Though inserting machine pins into single/dual wipe sockets may permanently depress the contacts in the sockets where they won't contact regular flat chip legs with enough pressure anymore.
  10. The 810 has no disk change detection method. It does not spin briefly when inserting a disk or closing the latch like the 1050 does. Some upgrades like the Happy use the write protect sensor to detect a disk change, but this is not a feature of the stock Atari ROM. The 810 also doesn't have a track 0 sensor. The powerup sequence moves the head from an assumed track 39 to track 0, then back to 39 before spinning down. If the head wasn't already at track 39 when it was turned on, it will end up "rattling" as it hits the barrier at track 0, which effectively re-aligns the head to track 0, and the firmware can assume it has definitely been positioned on track 0 after 39 backwards step attempts after that point. If the drive was successfully reading some sectors, and then gets some read errors, the failure/retry function of the 810 will seek the head to track 0, and continue to try to step it backwards causing it to again bump into the barrier there, to try to re-align the head at track 0, and then seek back to the track it was trying to read the problem sector from again. This could be due to an actual bad sector on the disk, a dirty read head, or intentional bad sectors /read errors due to copy protection. I would next focus on trying to clean the head.
  11. Ah k, so it sounds like your stepper motor isn't working. If you manually move the head to track 0 (outermost position) see if it powers up without the constant start/stop. This will confirm if your track 0 sensor is still working. If so, you may even be able to boot/read sectors from track 0 of a disk, until it tries to read another track. Can you take a picture of where the wires from from the drive mechanism connect to the 1050 mainboard at the back left side of the drive? They may either be disconnected, or connected incorrectly. A picture would potentially allow us to identify an incorrect connection.
  12. That's the POST failure mode. Something is not right that the firmware detected. First thought is track 0 sensor. I think I've caused this behaviour by disconnecting that. If you move the head all the way towards the centre of the disk and power up, does it step the head all the way back to the outermost track before doing the motor on/off cycling? If the track 0 sensor doesn't see the head "arrive" at track 0 this mode gets triggered. CPU and ROM may be good since that repeating pattern is following ROM code. Next up it could be bad SRAM in the RIOT or 6810, which can be swapped out of another 1050 to test...
  13. Hey All, I still have Kay's 810T PCB which he graciously lent me, and we've been in touch about it recently as well -- I apologize to all on the lack of timeliness on my intended plans of getting this thing installed to witness a real-world working double-density 810. The effects of Covid-19 and my job moving to primarily work-from-home the last few years has taken a toll on the organization of my home office and space allocated to Atari projects... but this post gives me renewed impetuous to get that corner of the world back into order! I absolutely would also like to see this board reverse-engineered and replicas made. I had emailed tf_hh in the past and he expressed interest in receiving it after I am done with it for exactly this intention. Previously I was able to identify 1 of the two LS logic chips that weren't soldered directly to the PCB using the LS test options in my miniPro programmer, but the others will likely require probing once it's in operation, and/or careful desoldering from the PCB (& socketing of course) to test separately. (The loose chip with the white wire attached is a 74LS04) So, I hope to have more to say in the near future with more updates, and hopefully this thing actually works!
  14. Can you confirm you used the "P. Format Single" option in DOS 2.5? otherwise the regular format option "I." will format the disk in Dual/Enhanced density, which is unreadable by an 810. OK, we can see in your video that it indeed goes through the motions of formatting tracks from 0-39, but then gets stuck when it tries to verify on track 39, supporting the evidence that it can not read anything back. Can you try cleaning the head? Use a little isopropyl alcohol / rubbing alcohol on a q-tip or fine/microfibre cloth to clean the ceramic head underneath the pressure pad and wipe it clean with a microfibre cloth. Then repeat the tests again. OK this at least indicates the erase component of head is at least partially functioning, if the pre-existing content was trashed by the 810 format. One other thing to try when trying to read a disk, or even at the phase of the format when it reaches track 39, try applying a tiny bit of downward pressure on the pressure pad with your finger to see if it helps get a sector read, or if the format progresses any number of tracks backwards from track 39 with that pressure applied... If so, you might need to adjust the pressure spring to another one of the three "slots" , or some other adjustments to tighten the spring (ie inserting something in between the spring and the pressure pad arm like a small piece of eraser, etc)
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