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techknight

68LC040
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Everything posted by techknight

  1. techknight

    Portable and 12 volts !!!

    the PMGR chips are the same.
  2. techknight

    Portable and 12 volts !!!

    Hybrid is good, you have 5.18V of power regulation. you are gonna need to find a donor parts board and replace the PMGR IC.
  3. techknight

    Need some quick opinions on this 160 LCD.

    you could try getting a hot bar tip for your soldering iron, and reheating the ribbon back down. They are welded with a material to the glass. this can deteriorate or peel away if it wasnt a good "weld" to begin with. a hot bar will take care of that. But, be careful! In the factory a bead gets laid down by a machine, and then it gets hit with an ultrasonic transducer press and it welds everything together.
  4. techknight

    Portable and 12 volts !!!

    The hybrid is likely fine. The problem is most likely the PMU IC on the other end of the board, its probably toast. But to be sure, with the battery plugged in, press NMI and RESET buttons at the same time. This will reset the PMU. Measure the voltage at the transistor directly in the middle next to your 4-pin molex connector. its output should be 5.2V if you have that, the Hybrid is working. Then what I need you to do is attempt to power it up and feel around the CPU area with your fingers, mainly the 74 series chips near it if they are getting excessively hot. They fail often.
  5. techknight

    Fun with colour on my SE/30

    You could also spray the front CRT Glass with a rear projection paint, and use a micro LED projector with a mirror in the back to extend the throw-distance. It would give it the curved look. now THAT would be cool...
  6. techknight

    Fun with colour on my SE/30

    I have a few of those NEC panels, but they were all CCFL, and I had an 8.4" long ago, only ones I have now are around 10" They are all 90s TFT panels. I am shocked that a generic LCD controller would actually run that display, most of those older displays were a very early parallel standard with not enough RGB color bits to do anything.
  7. I have 3 prodrives now that exhibit the spin up, and spin down without any head actuation. I noticed on all 3 drives when paying close attention, What appears to be tantalum capacitors near teh power jack are actually aluminum electrolytics, and Guess what... They are leaking. everywhere. So, I know the drives work if you give the actuator head arm a little push on the platter, but they wont do it under its own power. I may have just found out why.....
  8. techknight

    VRAM SE/30

    You would have to create an oversampling, something that cant be done with the CRT without cranking up the frequency.
  9. techknight

    SCS2SD - Mac Plus bootable solution

    youll see a diode foot print behind the SCSI connector, thats where you put the diode. it feeds term power out the db25.
  10. techknight

    MacToTheFuture SE30 Network Card Driver

    I think you pretty much beyond all of us here currently, at least when it comes to apple dev. There are a few guys here that do it, but only one or two of us that have done drivers.
  11. techknight

    145B LCD recapped with tantalums

    Yea itll improve the image quality by an order of magnitude. Main reason is the passive matrix LCD requires a high driving voltage. around 40V or so for the sinusoidal signal to keep the crystals from developing a memory effect. If the caps are bad, it distorts that voltage and signal, seriously compromising the image quality.
  12. Peripheral card developers could get schematics from Apple under NDA. Thats how I obtained the portable schematics which are now public of course. It came from a defunct RAM manufacturer for the portable. I still have the PALASM documents, and some schematics, etc that I have NOT shared.
  13. techknight

    How to spot a counterfeit Capacitor

    Yea.... That member isnt here anymore, so unless someone else picks up the ball, thatll never happen.
  14. techknight

    ROM Interleaving tool?

    I would hate to write one if I dont have to, but is there a quicky little tool somewhere that can take the LOW/HIGH images of ROM and interleave them back into a single ROM image? I vaguely recall a thread about that but ill be darned if I can find it.
  15. techknight

    ROM Interleaving tool?

    my german skills are non-existent. I ended up throwing together a quick little program to do this. Been spending the past week or so disassembling and reverse-engineering a 68010 VMEBus based machine, trying to make heads or tails of it. Not getting too far.
  16. I guess everyones hearing tolerances are different. When I was a kid, I could tell if a TV was left on all the way across a room. But it was never really painful. But during those same days, I could never listen to FM stereo either because I could hear that 19K pilot tone. Now I am lucky to hear above 14khz before it all blends into my tinnitus. These days I hear the old school "tv flyback running" 24/7. Called Tinnitus. LOL.
  17. techknight

    Mac LC III 16mhz?

    I just picked up a macintosh LC III and it works ok, although the capacitors are failing. What i noticed, is everwhere i read the macintosh LCIII has a 25mhz 030. Mine has the exact logic board an LCIII would have, but it has a 16mhz 030. Any ideas why?
  18. techknight

    MicroMac Performer SE Mod

    Without seeing the schematic and the GALs actual native boolean logic, its just a blindfolded shooting match guessing game. The GALS functions are basically to emulate the E/VPA/VMA system, maybe some simple address decoding for a DeclROM, and the bus master takeover, using the Bus Grant, Granted to take over the 68000 before it will release the 030 from running.
  19. techknight

    MicroMac Performer SE Mod

    Yea I know. It took me awhile to figure it out, but once I did I began to understand it. I needed to if the RAM card was ever gonna work.
  20. techknight

    MicroMac Performer SE Mod

    68K communication is asynchronous by nature. it could run at 500Mhz and the bus at 8Mhz, it wouldn't matter. You would have a shit ton of wait states but it would work. The catch is the E/VPA/VMA of the synchronous bus. It would need to be locked to the system bus if the system uses these, and the Mac does. the VIA, etc use it. So there would be PALs/GALs that interface with this, and thats that.
  21. techknight

    MicroMac Performer SE Mod

    8 goes into 32, but not 33 or 25. Not sure how they can get 8 from either of those. It would require a PLL.
  22. techknight

    MicroMac Performer SE Mod

    If they are generated separately, They dont. One has to generate the other, and they lock by phase, thats it.
  23. techknight

    MicroMac Performer SE Mod

    According to some of the articles I found, it was mentioned never to use this circuit design. Probably why have never heard of it. So you dont need a GAL here. Just use a clock multiplier IC and form a small circuit around it. Like this one: https://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10001&langId=-1&freeText=pll-clock-multiplier&storeId=10001&productId=2054361&krypto=4We6orF%2FQq5lWZdXyYEvrdAYAdhOJj8HYljOOKxHoLoVxQzggZZcSX2XGmFUnAG0lQR7Dh4ZNJ0lR8bZ3KHdN3xKnbBF4dPsto26knu2gUY%3D&ddkey=https%3AStoreCatalogDrillDownView
  24. techknight

    MicroMac Performer SE Mod

    Nevermind. Power of google. Wow, I never knew such a thing existed. Any time I needed to double or multiply frequencies, I just used a PLL with a divider in the feedback loop. Hmm learn something new everyday. Sadly from what I see on google, an XOR multiplier requires a delay to be exactly half of the half-period so it can be 90 degrees out of phase. So if the clock changes in frequency, it will shift the duty cycle, but that is a cool way to make a frequency to PWM converter.
  25. techknight

    MicroMac Performer SE Mod

    Not sure how delay lines double frequencies. Thats one thing I never personally ever saw. But that can explain the DS1013M delay ICs I have just recently seen in a 68K based graphics generator board.
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