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sigtau

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About sigtau

  • Birthday 06/11/1994

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  • Gender
    Male
  • Location
    Minneapolis, MN
  • Interests
    Old shit's cool shit.

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  1. sigtau

    Millenium bug after 20 years?

    Two questions: Classic or Classic II? I couldn't tell from the video. What version of System is that? I want to say 7.0.1 but I may be wrong. The question then would be if later Macs suffer from similar issues.
  2. There is no video RAM inserted at all, and I don't have an external video card to test with. I've done a fresh PRAM and CUDA reset as of this post, and still no change in the board's behavior.
  3. sigtau

    Macintosh Color Classic Sound Issue

    Capacitor issues around the audio DAC chips in anything from the II, LC, or (Color) Classic series' usually results in dead, or very faint, sound. That would be my first suspect too. To test it out, you can first desolder and replace the caps around the TI amp/dac chip, which should be labeled 343S0129, and then try powering it on to see if you get sound. Warning: If you go with tantalum chip capacitors like most of the people around here do, note that the polarity stripe on tantalums denotes positive, and not negative. Certain tants can be quite explosive if connected backwards. Make sure the stripe side is positive. If you do replacement aluminum can caps, this is a non-issue.
  4. ROMs are not socketed, it appears to be some kind of single chip, like a PLCC or something to that effect. I don't know which it would be, there are no DIP chips on the board. And I think I mis-wrote that post: I tried Apple Hardware Test and it wouldn't boot, but then tried a separate program, TechTool Pro, which tests all hardware facets you can throw at it, and it crashed immediately. OS 9.1, no extensions. I have a second CPU and I swapped that out, and it crashed with that one too. Performing a CPU test with both also crashes it. The RAM test, however, succeeded with flying colors. The RAM is all good. I am all but certain this logic board is toast.
  5. Results: I couldn't get the Apple Hardware Test to boot, but I could get it to run TechTool Pro to run on it, which upon attempting a full test of hardware, crashed immediately upon testing the L1 cache. I swapped out the CPU, got the same result, though a markedly faster boot time. I removed the cache module entirely, now doesn't boot at all (powers on, but the power light does not turn on, sits there with seemingly no activity on disk or on screen). Another thing I forgot to mention: when booting after being unplugged when I work on the inside, the computer first goes to OpenFirmware and repeats this message as follows: can't OPEN: can't OPEN: can't OPEN: can't OPEN: can't OPEN: can't OPEN: can't OPEN: can't OPEN: can't OPEN: can't OPEN: can't OPEN: can't OPEN: It then reboots, and goes into OS9 just fine.
  6. I've tried every stick individually to no effect. The contacts have been cleaned. I'll try an actual RAM test next.
  7. Troubleshooting advice would help too, but I am fairly certain I have a PM G3 beige minitower that is on its way out. Fresh PRAM battery, all expansions removed, minimal system connected (with the exception of a SATA card later on). Power supply voltages are golden, within 10% or less of the rating. Symptoms: No chime at boot but it does boot. OS 7.6.1 and 8.0 can play audio through the speaker when using them in a Norton Utilities envrionment, so I know that part at least works. Boot RAM test takes a very long time. After a long period of being unplugged, nuked PRAM or otherwise, sometimes it does not show video at all. Intermittently responds to ADB power-on/power-off keypresses. CPU barely heats up, contrary to my experience with the G3 in the past. Sonnet PCI SATA card, designed specifically for this Mac, being used as a disk, and OS 9.2.2 can see it but OS X of any version cannot. In fact, OS X can see IDE disks on the motherboard's controller, but no SCSI disks, or intermittently it can see SCSI. OSX install takes an eternity to complete, which in past runs with this computer, is a new problem--usually it takes about an hour at the most, with this taking up to 3 hours now if it's installed to a CF card under IDE. OSX 10.1 and 10.2 can complete their installer, but 10.3 kernel panics despite being rated to run on a G3. All RAM sticks test fine in other machines. I am more or less convinced this board is gone, but I don't know if there is anything else I can do to salvage it or repair it before I go scouting out a replacement.
  8. sigtau

    40p SCSI to 50p SCSI

    I wasn't aware of these... but now I'm tempted to try them. I think the biggest issue with these might be that you have to find a short enough SCSI cable to accommodate it, because the v5 only fits horizontally into the bay, rather than vertically, and the laptop's own ribbon cable cannot be turned or twisted without damage because it is designed to fit a particular way. Also, the PB SCSI is 40 pin, and is being adapted to 50 pin, so this may be useless for the purposes of a powerbook. Apple being proprietary Apple, as always! Might help with those early Toshiba laptops, pre IDE... It definitely would have magic smoked the laptop's scsi chip, at minimum. The connector was physically flipped, vertically, meaning 5V was shorted directly to GND. Would not have been pretty, and makes me want to tie the 5V rails together and put them behind a Schottky diode in the next revision.
  9. sigtau

    40p SCSI to 50p SCSI

    Oh, hey, this actually garnered interest! So the first run I ended up accidentally orienting the plug incorrectly and--if I hadn't noticed sooner--would have almost fried my v5 SCSI2SD. It's my mistake because I think I expected the mini-scsi connector to be oriented one way when sketching the schematic, then oriented the PCB backwards. As it's very cheap to manufacture the boards I plan on doing a second, revised run this month. If you want one, reply to this thread or PM me as I have a e-mail notification for this thread, I'll get to you when the time comes here in May.
  10. sigtau

    Mac 512K, upgrading to Ke standard.

    Excellent! Thank you for the insight. Whatever I end up sticking with I'll make sure the 64k ROMs remain safe as those seem to be the more valuable piece between the two.
  11. I have an original 512K and I'd like to see if it's possible to get it up to 512Ke standards (800K floppies, etc). Would I need to simply transplant Plus or Ke ROMs into the 512K, or is there more involved? Furthermore, is it even possible/practical?
  12. I did end up finding this thread: http://www.oldschooldaw.com/forums/index.php?topic=433.0 I've composed a Windows 98 bootdisk, attached below, as a 1.44mb floppy image, with the firmware onboard. I will try it when it arrives, and if not, no harm done. These cards are common enough, and I can always brute-force it by programming the ROM directly. W98_SATA_3112_Mac.img
  13. I've got a PB3112SATA150 card coming in the mail. I've read on here that it's possible to flash the chipset to be bootable in the Beige minitower G3 but I have no idea where to begin/what to search on how to go about doing this. Anyone have a link/guide/pointers on how to do this? I have a few PCI-compatible PC motherboards I can pop it into to do the deed.
  14. sigtau

    40p SCSI to 50p SCSI

    Absolutely. As I said in PM, I'm building two variants and I want to see which one fits more snugly--SCSI2SD beneath it or above it. They are cheap to produce individually ($.50 per board, $3 for the connectors) and will likely be dirt cheap in bulk. The one I have posted here so far fits ABOVE the SCSI2SD.
  15. sigtau

    40p SCSI to 50p SCSI

    The first batch has arrived! I'm about to head off for Christmas but I'm going to order the parts from DigiKey or Mouser in my absence and they should be there by the time I get home. It fits snugly in less than the size of a PB-SCSI hard drive, leaving just enough overhang for the SCSI2SD v5 to fit in the remaining space.
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