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fri0701

6502
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  1. Vintage Mac Safety

    Also, safety aside, keep in mind that leaving a CRT on for long hours showing the same screen is never a good idea for the health of the machine.
  2. Macintosh 128k boot problem on floppy.

    If you're sure the drive's read head is clean, you might want to check out replacing the Bourns Filters on your logic board. This problem seems similar to yours - maybe it can lend you some insight into your problem: https://68kmla.org/forums/index.php?/topic/22419-m0001-floppy-drive-problems/
  3. Great job! It's always great to see one of these come back to life.
  4. Apple /// Problems

    UPDATE: Looking at the voltages on the 6502 processor, something doesn't seem quite right. The address lines look like clean square waves, but they are only about 3.5-3.7V peak-to-peak. The data lines look very distorted and jumpy. The clock signal on pin 37 is only running at ~1MHz, and also is around 4V peak-to-peak. The Apple III should run at 2MHz, and transition to 1MHz when the processor is reset. However, it seems mine runs at ~1MHz, and doesn't transition when the processor is reset.
  5. The Lisa stores its information about its serial number (for use in copy protection) in the Video ROM (C6 on the CPU board). I don't know what would be causing your error if you haven't replaced the CPU board or that chip specifically, but there is a command you can run from within service mode where you can see the serial number the Lisa "thinks" it has. Maybe you can try checking that and see if it matches with the number on the case? Information here about querying the serial number: http://www.applefritter.com/content/apple-lisa-serial-number-info -fri0701
  6. Lisa needs some CPR

    It's important to note that although the Lisa will complain about not having a keyboard, it is not required, and the system will still boot. You'll hear any error beeps / see any error codes about 3 seconds after the Lisa notifies you there's no keyboard attached. - fri0701
  7. Lisa needs some CPR

    If you've got a 2/10, your Plus mouse should work without any modification of the connector. Here's a site with all the Lisa schematics, including the PSU: http://lisa.sunder.net/cgi-bin/bookview2.cgi?zoom=0?image=0?book=6 The Lisa PSU has a small hole on the side that leads to a potentiometer for varying the output voltage. Be careful if you play with this! I'd suggest unplugging the Widget entirely until you can verify the power supply is working, since adding a load like a drive might influence your measurements and results. At least the 2/10 never had the infamous batteries that kill so many Lisas. The normal Lisa boot cycle goes as follows: Power button is pressed, and power switch light goes on. A faint whining noise may come from the power supply. ~3 seconds later, a "click" is heard ~15-20 seconds later, two "clicks" are heard in short succession If there is no keyboard connected, you will hear beeps in the pattern: 2 high, 1 low. A keyboard with a question mark will appear on the screen. If there is no boot media, or it cannot be booted from, you will hear beeps in the pattern: 3 high. An "no boot" error code will appear on the screen. If the Lisa encounters any problems during its self-test power up, it will display an icon and an error code (if it's able to get that far, that is). The icons and error codes can be interpreted using this (page 19): ftp://ftp.apple.asimov.net/pub/apple_II/documentation/applelisa/Lisa_Do-It-Yourself_Guide.pdf Feel free to PM me if you have any specific questions - always happy to help resurrect a Lisa. Good luck! - fri0701
  8. Apple /// Problems

    Hi everyone, Well, once again, I'm back to attempting to fix this stubborn ///. I've made some progress, and I'm hoping someone experienced enough can recommend what I should try next. I've caved, and purchased a Reactive Micro Universal PSU and installed it in the ///, with no change. At least now I can be definitely sure that the power to the system is clean and functional. All voltages check out. I also (finally) got my oscilloscope up and running, and probed some chips based on this guide: http://www.willegal.net/appleii/appleii-repair.htm The 6502 CPU is running correctly, it seems, with the reset pin jumping to high as I start the system. The reset pin jumps to low and back to high whenever I push Control-Reset on the keyboard, which is a good sign. I can see activity on the various address and data lines, as well. My RAM chips are new, and I doubt they're the problem. I've tested the Vcc supply on all chips, and they are all at the correct voltage. However, my screen is still a flashing mess of jumbled characters. When I remove the 5V RAM board from the system and turn it on, the screen is solid white. Is anyone here experienced with digital logic troubleshooting, who can guide me through where to check next with my scope? I unfortunately don't have any spare chips to swap and try here, although I do have some spare Apple //es that I could harvest from, and I could definitely order replacements if needed. I'd really appreciate any help to finally resurrect this beast! - fri0701
  9. Apple Lisa with Asset tags

    Nice! Mine has both labels; the metal one on mine is #12810.
  10. Apple Lisa with Asset tags

    I also happen to have a Lisa with a property tag, like yours. Mine is #A0613, and was given to me by an old Apple programmer who (he thinks) used it to program Macintosh software (it's been a while). It's a Lisa 2. I believe these were just normal production machines used for development or use within Apple, so they put asset tags on them.
  11. ColorView SE? What's that?

    I think I may have found some information for you! Here's a page from InfoWorld about this "mystery" card: https://books.google.com/books?id=5T4EAAAAMBAJ&pg=PA60&lpg=PA60&dq=%22colorvue%22+se+macintosh&source=bl&ots=lHtdfccQDO&sig=HWC9KlO7z2ggdVQHAiasmPA8C88&hl=en&sa=X&ved=0ahUKEwiBt_SxsfjRAhWGQCYKHRM3CtwQ6AEIITAB#v=onepage&q=%22colorvue%22%20se%20macintosh&f=false And some information from Low End Mac: http://www.lowendmac.com/video/68k/index.html Hope this helps!
  12. Head hurts, IIvi versus IIvx

    Not sure if you're still looking for these, but my IIvx has a 820-0373-B.
  13. I'm in the process of replacing my Lisa keyboard's foam pads, and I realized that the caps lock key doesn't stick halfway down like it should. I'm afraid I may have lost something from the mechanism that makes this work. Does anyone happen to have any detailed pictures of the caps lock assembly (or would anyone be willing to take them, for science? )
  14. Apple /// Problems

    Thanks for your input. I've ordered some new RAM and we'll see what happens. I appreciate the offer, khannonnd, but I'm in Michigan and I doubt you'd like to send it off that far. I've already replaced the one electrolytic capacitor on the RAM board, checked the continuity of all the pins and traces, and am ordering new RAM. Is there anything else on that board I should check or anything else that could go wrong on it, to anyone's knowledge?
  15. Apple /// Problems

    Hi everyone, I'm back for the holidays and am giving another go at this stubborn Apple ///. I'm happy to announce that I think I'm getting somewhere finally! When I recapped my power supply a while ago, I found a suspicious testing transistor in place of where IC1 should go. After researching it a bit, I discovered IC1 is a voltage regulator (there was no information on the transistor that was taking its place). I just ordered and installed the original IC1 chip, as specified in the original Apple schematics (TL431CP). With this chip installed, at first, it looked as if nothing had changed. Then I examined a bit further... It turns out that now, the screen no longer flashes random characters, as it used to. Now, it simply shows a non-moving screen full of "characters" (more like a character-sized pixel pattern, all the same, filling up the entire screen). I am only running a single row of RAM on the upper row. Even when I remove any subset of these chips, even all of them, the same pattern comes on the screen. Furthermore, I tested the supply under load from the computer while it was running. Here's what I got: +12V supply: +12.66V (5.5% error) +5V supply: +4.98V (0.4% error) -5V supply: -4.90V (2% error) -12V supply: -12.34V (2.83% error) I believe these voltages are all within reason! (ScutBoy, perhaps this is why our supplies both had the -5 and -12 supplies measure lower than expected, since we weren't measuring under load) I think now that the PSU is stable, the next thing I might try would be to simply replace all of the RAM chips. My testing strategy of placing them in my //e has proven unreliable, and I wouldn't be surprised if any of them have gone bad in the process. I believe they should all be D4164C chips. Does anyone know a good place to buy these from? I don't believe you can buy them new anymore, and so far, the only place I've seen to buy them in the quantity I need is off eBay. I'd really appreciate any thoughts on this, as well as any insight anyone might have into the current repair state of my machine.
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