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rsolberg

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  1. rsolberg

    Where to buy 60ns EDO RAM?

    As noted by itsvince725, the 440FX chipset doesn't have SDRAM support, so it needs EDO. The 440FX was used for the Pentium Pro/Socket 8 and early Pentium II/Slot 1 systems. In retrospect, it seems a rather weird regression from Pentium systems with SDRAM support to early PIIs without it. The 440LX chipset added SDRAM and AGP support. While the 440LX and later 440BX still supported EDO, SDRAM could offer twice the throughput and it seems rare to find EDO installed. The trade off is that those chipsets support less SDRAM than EDO: 512MB of SDRAM vs 1024MB of EDO. The EDO used by these systems is 3.3v and unbuffered and the DIMM slots are keyed to accept these as well as the more common 3.3v unbuffered SDRAM DIMMs Power Mac EDO DIMMs were 5v, buffered, and keyed differently to avoid mix-up. *The Power Mac 4400/7220 and many Mac clones used unbuffered 3.3v EDO DIMMs, more like PCs. I had a 440LX AT (not ATX!) system somewhere in the mid 2000s and I found it such an oddity. It had both AT and ATX power connectors, 2 DIMM slots for SDRAM or EDO, 4 SIMM slots for EDO, USB, onboard audio. Since it was AT, it only had an AT keyboard connector at the back edge. Everything else used headers. My guess is that boards like that were marketed to shops upgrading existing late 486 and Pentium PCs since they could use the existing case, power supply, and even RAM.
  2. rsolberg

    Color Classic and LC575

    It sure can. That's essentially the "Mystic" Colour Classic upgrade/mod. Before swapping the 575 board in, you can make a small modification to your System file with ResEdit so that it starts up in the right video mode for the CC's analog board/monitor. This won't affect booting with the stock CC board; it just changes the boot procedure when the 575 board is identified. See item 2.1.3 on this page for steps: http://www.colourclassicfaq.com/mobo/mystic.shtml When I did this, I remember booting from a floppy to replace the System file with the modified version, but I can't remember if that's strictly necessary. If you have a working 575 board and don't do the edit, I think you'll get a chime but no video.
  3. rsolberg

    what is this white stuff on board

    The product/goop I think you're looking at is often referred to as Silastic, Dow Chemical's trade name for the product. It's a elastomeric silicone rubber/polymer used both to secure heavy components and support components that stick out from the PCB considerably, such as large electrolytic capacitors. The product is used because it doesn't break down or melt, even with repeated thermal cycling. Importantly, it's inert, unlike common acid-curing household silicone sealants that will corrode PCB traces and component leads.
  4. rsolberg

    Insane SCSI to FW prices

    On the 512 byte block size optical drive topic, VAXStations also required it to boot. I wonder if this was a de facto standard among UNIX workstations of the era?
  5. Maybe this is technological masochism on my part, but one of my first experiments after BeOS would be to try Debian 8 (Jessie) on the Quad 604. The thought of something that modern on what's essentially a 20 year old high end workstation makes me giddy. Maybe NetBSD too........
  6. rsolberg

    Macintosh SE repair help

    The single horizontal line issue is typically caused by a failed chip on the analog board as detailed in The Dead Mac Scrolls: https://archive.org/details/mac_The_Dead_Mac_Scrolls_1992/page/n163 and shamada's Repair Mac page: https://web.archive.org/web/20150206072538/http://www.biwa.ne.jp/~shamada/fullmac/repairEng.html#HorizontalLine Did you replace the analog board (oriented vertically on the side of the Mac,) the logic board, (oriented horizontally on the bottom of the Mac,) or both? If you replaced the analog board or both boards and the problem went away, then it's probably the TDA1170 chip on the old analog board as described in the links above. If you did not replace the analog board, but replacing the logic board fixes the problem, it's a much less common issue and is not well documented as to what may be causing it or how to remedy it.
  7. rsolberg

    5x0(c) CPU card differences

    Whoops I'm wrong! The 5xx series CPU daughtercards use a 4x frequency multiplier IC between the oscillator and CPU. This means that a 12.5MHz oscillator's clock is multiplied x4 to 50MHz for the CPU's external clock input, running the CPU at 25MHz. I would still aim for 33MHz for stability's sake, so that would require a 16.7MHz oscillator.
  8. rsolberg

    5x0(c) CPU card differences

    If you can find a genuine MC68040FE40A, then that might be a good option. The 68040 series operates at half the frequency of its input clock. That means a 20MHz oscillator would run the CPU and bus at only 10MHz. In the case of the 520c, a 50MHz oscillator is used to set the 68LC040 and its bus at 25MHz. If you were to replace the original CPU with a 33 or 40MHz-rated version, the new CPU would still operate at 25MHz. Replacing the oscillator with a 66MHz unit would yield 33MHz CPU and bus. 80MHz oscillator would give you 40MHz. Keep in mind the CPU and bus are at 1:1 and some logic board components may not work reliably or at all at the higher speeds. RAM and VRAM are just some of the usual suspects. It seems pretty likely to me that the 520c would work at 33MHz with a 66MHz oscillator, but I'm doubtful that 40MHz is achievable without issues. Remember that heat dissipation climbs significantly with a small frequency increase. Also note that the "full" 68040 with FPU dissipates significantly more heat than an equivalent 68LC040 at the same clock. If you can find a genuine MC68040FE40A for a reasonable price, it's likely to run cooler with a 66MHz oscillator (at 33MHz) than a MC68040FE33A would.
  9. I'm not aware of an IOXperts Airport Extreme driver for OS 9. I am familiar with their driver that allows use of "unsupported" 3rd-party PC Card WiFi cards in Mac OS 9 and X though. I was going to refer you to their website as I bought said driver from them a few years ago, but I see their site no longer exists.
  10. rsolberg

    PB145B’s finds

    Looks like the kits are discounted to $24.99 US now, LCD not included. See realmacmods.com
  11. rsolberg

    PB145B’s finds

    In case you're not already aware, you can get an adapter board from realmacmods that allows use of a non-Apple replacement panel in your 17" iMac, including a higher resolution 1680x1050 or 1920x1200 panel. I bought a kit that included plastic mounting rails/adapters from them. I sourced a used a 17" 1920x1200 matte panel from an Alienware laptop on eBay. I like the extra real estate, and it was way less expensive than finding a working Apple replacement part at the time. My late-2006 Core 2 Duo 17" machine dual boots 10.7.5 and Debian nicely. I'm fortunate not to have too many X1600-related problems after reapplying thermal compound. I expect the GMA 950 would be even easier to configure in Linux than the X1600.
  12. rsolberg

    SCSI zip drive

    For anybody in the Pacific Northwest, Seattle RePC has a couple large totes full of external ZIP drives. Most are parallel, but there were quite a few SCSI units as well. I briefly considered a 250MB external SCSI, but I realized I wouldn't have room in my luggage for the flight home. I did pick up some PhoneNet dongles, serial cables, internal 50 pin SCSI ribbons, a brand-new 45w "yo-yo" power adapter, and its predecessor, the black rectangular PowerBook 45w adapter. They had more of both in apparently good shape. I also found a PowerBook VST Zip drive mixed in with hundreds of PC optical drives, but I left it for somebody else to find. Also of note, they had a bunch of Jaz, Cliq and other less common removable media drives.
  13. rsolberg

    Brand new PowerBook 1400 CD-ROM

    I've had saved searches on eBay for "PowerBook 1400 CD-ROM" along with all of the relevant Apple part numbers for a few months and it finally paid off. I managed to score a brand new in box 8x unit and it works great. When I opened the box, it clearly was brand new. The drive was still sealed in its plastic sleeve and there wasn't even a speck of dust on it. I'm almost finished my 1400c/166 hardware. I have to finish assembling my replacement NiMH cells into the battery pack and then I'm all done!
  14. The tray loading (233-333MHz) and slot loading (350-700MHz) iMac G3 logic boards are a completely different shape and size, with different electrical and cooling requirements, different monitor connections, so swapping from one family to the other isn't very practical. Some slot loading logic boards can be swapped into other slot loading iMac G3s, but there are some differences on later boards that may complicate things. I'm not as familiar with tray loading iMac G3s, but I believe the logic boards have interchangeability between revisions.
  15. EvilCapitalist's suggestion is a good one. If the drive powers up without anthing on its IDE connector, it's probably a jumper setting. If it doesn't, your power brick may be failing. I've had some of those fail before. One would spin up some drives, but not others due to differences in current required for spinup. I explicitly remember having a problem with iMac Maxtor drives and IDE/USB interfaces. I think the drive needs to be configured as Master in the iMac, but I had to change it to Slave (or maybe Cable Select) for it to cooperate with the adapter. Here's the jumper settings for your drive: http://www.seagate.com/staticfiles/maxtor/en_us/documentation/quick_specs/diamondmax_30_vl_ultra_ata_100_quick_specs.pdf
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