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ymk

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Everything posted by ymk

  1. Great review of a neat accessory. The Kensington seems like the best looking option out of the group.
  2. You didn't think that was worth mentioning?
  3. It is a bad idea. Continuity still exists between 5v and 12v and about half of the pins in the SCSI cable are GND anyway. SCSI isn't hot-pluggable, so what would you have gained?
  4. Interleaving the signal lines with grounds reduces crosstalk. ATA/66 accomplished this without giving every ground wire in the cable its own pin on the board.
  5. Hi Dmitry. We've been in contact on Ebay. Like I mentioned, I don't have an 8500 to test with, but I've ordered a 7500 which also has the fast internal bus. Since you've confirmed MacSD works with the 8500's external bus, I still recommend using that for now. I will message you when I know more about the issue.
  6. Have you tried the MacSD as the only device with the resistors in the pull-down configuration?
  7. Signal reflections. The devices should be laid out in a line: End of 50-pin cable -------- middle of 50-pin cable -------- SCSI controller on logic board -------- DB25 external connector ------- external device 1 ------- external device 2... Branches (as in a USB hub) should be avoided. Adapt the DB25 to a 50-pin header, like the logic board uses. Then you can connect both external devices using a 3-connector 50-conductor cable and terminate the one on the end.
  8. SCSI devices are wired in parallel, but the physical layout matters. Wiring devices in a star or T layout is asking for problems.
  9. There is currently no Powerbook version of MacSD. Transfer rates are typically 1.4-2.3 MB/s on a PowerMac 6100, depending on clock speed and card. I'd expect the lower end of that range on a PB180.
  10. I've recapped many Classics and Classic IIs. The Classic especially, has many traces running underneath caps and with time, they will be eaten through. An ounce of prevention is worth a pound of cure here. I'm not asking you to send them to me, but don't run vintage hardware into the ground.
  11. Your monitor might have an "Auto" function to adjust to the signal timing.
  12. Some more options: Reset the PRAM Boot with the mouse button held down Use SCSI IDs 0 and 1
  13. For now, try swapping the HDD and CDROM SCSI IDs. Edit: If you haven't yet tried booting with the CDROM at 4 and the HDD at 0, do that first.
  14. Use the Startup control panel to set the boot device. Then you should be able to re-enable the CDROM without problems.
  15. Great! Overlap isn't happening if it's the only device. Most likely, the Mac was trying to boot from the Apple Legacy Recovery CD at SCSI ID 4.
  16. That's a good sign. On line 9 of the macsd.ini file, change the HDD SCSI ID from 5 to 0. Also add semicolons at the beginning of lines 3-7 (starting with "[4:cdrom]"). This will disable the emulated CDROM.
  17. Both resistor packs are either installed or removed. There should never be just one installed. The yellow resistors have a grey dot to mark pin 1. The DIP socket has one more pin than the resistors, so one position per row on the socket is left open. Looking at the PCB so most of the text is right-side up, pin 1 of the resistor pack is always on the edge of the DIP socket; on the left edge (labeled VCC on the PCB) for pull-up mode, or to the right edge (GND) for pull-down mode. Good, then your MacSD is probably OK.
  18. Hi Tom, I just spotted this thread. The MacSD ships with pull-up termination. To run it together with an HDD one of the following must be done: Remove the HDD's resistor packs Remove the MacSD's resistor packs (FPT termination) Change the MacSD's termination to pull-down (pin 1 in the GND column, usually needed to work with Quantum's 110 Ohm resistor packs) There is potential for damage if multiple devices are providing termination. If it turns out yours is damaged, you can send it back for repair. First, try to get the MacSD running by itse
  19. That's certainly possible. I just threw out a rough estimate. Are 80ns modules fast enough for all Macs?
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