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johnklos

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  1. johnklos

    China Ebay 68040 processor

    My kitty will volunteer one for you. If you have a good thermometer, measure the idle and busy temperatures of the CPU before you replace. I got a few m68040s which were supposed to be the newest mask which got just as hot as an old early 1990s mask before I finally got a real new one.
  2. johnklos

    Bad caps leading to slow performance ?

    The only time I've seen caps affect speed is when the SCSI bus was affected and got lots of errors due to capacitor problems. I couldn't see any issues in Mac OS, but in NetBSD I'd get SCSI errors in a constant stream. Recapping fixed the SCSI, and disk access went from painful to what we typically expect (mediocre).
  3. There's only a 2 TB limit. While the SCSI chips support drives larger than 2 TB, the limit comes from using just 32 bits worth of blocks (four billion 512 byte blocks). SCA isn't a problem so long as you get adapters with high line termination, like so: https://www.ebay.com/itm/SCA-80-Pin-to-IDC-50-IDC-Male-Adapter-with-High-Line-Termination/233090532398 Likewise, 68 pin SCSI drives with 68 to 50 pin adapters work fine so long as termination is for all 68 pins, like so. The 50 pin motherboard connector has an adapter to go to 68 pin, and the 68 pin drive (SCSI to IDE) and terminator are both 68 pin.
  4. johnklos

    640x480 on LC II?

    Welp. I tried on my LC II, too. I even found a monitor adapter with switches, set the screen depth to 1 bit, and removed the VRAM. I get the grey screen and that's all. The machine boots, but I can't see anything. While looking for the monitor adapter with switches, I came across a 512K VRAM SIMM, so I guess I don't need to do this anyway, but I was definitely curious
  5. johnklos

    Best way to bootstrap LC II without floppy?

    Just posting for future reference. I eventually got everything working on a 250 meg CompactFlash card in the PCD-50B by using a SCSI2SD set to the same number of sectors as the CF card. For some reason, the CF card in the PCD-50B fails when I try to initialize it using Drive Setup or HD SC Setup (both patched, of course). The SD card in the SCSI2SD worked fine, so I initialized, copied the System Folder and programs, then used dd to copy the SD card to the CF card. The nice thing is that I can just connect the CF card to my Mac, chown my user /dev/disk2 (or whatever it comes up as in diskutil list), then give /dev/disk2 to Basilisk II, then access the CF card right from Basilisk.
  6. johnklos

    640x480 on LC II?

    After seeing mention about how the LC and LC II can do monochrome video when no VRAM is installed, I tried it. It didn't work. Then again, my multiscan adapter only works with my LC II in 512x384 mode. So, even though the machine booted, nothing beyond the boot grey appeared on the screen (the boot grey is unlike other models - it comes on immediately on power up). After checking in Apple Service Technical Procedures, I see that it is only supposed to work in 640x480 mode (Basics, 1.18): Does anyone know what I'd have to do to make the LC II run at 640x480? Do I need a diode across pins 7 and 10 of the video connector, like in the first diagram here?
  7. johnklos

    68882 FPU p/n & mask

    I've never heard of issues with different masks of m68881 or m68882. From where did you get the impression that it might be an issue?
  8. Very, very interesting... I just recapped an LC II board and tested it with VRAM installed. I'm going to give it a try without.
  9. I've got an LC II motherboard which Brett B. kindly sent me. It needed a good cleaning and recap, and now it seems to work. I connected the PCD-50B SCSI card reader that I use with my Quadra 605, and although the LED flashes shortly after power on, it won't boot. It occurred to me that the SCSI drivers installed on a drive might work fine for certain m68k machines, but not others. I'd try some different ones, but I don't want to screw up the working Quadra, plus I don't have a floppy drive for the LC II. Can anyone recommend a good way to make a bootable disk using the Quadra that will definitely work on the LC II? Or, if not via the Quadra, perhaps from Basilisk II or Mini vMac?
  10. I'm pretty sure that's the case...
  11. I seem to remember that any model less than 6400 should be fine. A 6400 or higher model motherboard will have a 3.3 volt line which would end up getting 5 volts if put in to a Quadra 630 case. A Quadra 630 motherboard in a 6500 case might short the power supply's 3.3 volt and 5 volt feeds. If you get the pinout for the 6500 power edge connector and check for continuity on the Q630 board, you'll know for sure. I went the other direction - I put a 6400 board in a Q630 case, but I had to cut the 5 volt pin off, then insert 3.3 volts to the board from my own added regulator.
  12. Keep in mind that many PowerPC cases will put out 3.3 volts on one of the pins, so don't plug in a Quadra 630 motherboard without checking pinouts first...
  13. johnklos

    China Ebay 68040 processor

    I've bought several m68040 / m68060 CPUs which were supposed to be the latest mask. Each time, when I've identified them as older, re-labeled CPUs, I've gotten a full refund and haven't had to mail back the CPU. I think most people don't check, or they think they're getting a CPU that should run cooler but doesn't. The bad part is that the sellers never get punished. At least the m68060 tells you its version. There are errata which can be checked for in m68040s, but that's tricky and can only broadly tell you what group your CPU is in.
  14. A 128 meg SIMM will definitely work in a Quadra 630.
  15. The LC475 can take 64 and 128 meg SIMMs just fine. I think the idea is that the IDE Quadras only have four banks of memory total, so one bank is the 4 megs on the motherboard, the other is the single bank SIMM socket, and the other two are the dual bank SIMM socket.
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