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Thread: Lo-tech XT-CFv3 versus Texelec's "Lo-tech ISA XT CF Adapter rev. 3"

  1. #1

    Question Lo-tech XT-CFv3 versus Texelec's "Lo-tech ISA XT CF Adapter rev. 3"

    Sorry if this was discussed somewhere but I could not find it.

    Lo-tech (for anyone reading this and not knowing) is the designer of the XT-CFv3 and shows this as the board on their Wiki (see attachment 1). It is surface mount, and with an integrated Compact Flash bay and bracket.

    TexElec (again for those not knowing) is a sanctioned distributor for LoTech and is calling their version(see attachment 2) "Lo-tech ISA XT CF Adapter rev. 3", but it is a through-hole setup (with a surface mount on the back of the PCB, no Compact Flash bay, no bracket, and utilizing an IDE-40 pin male header).

    Clearly not the same board, and IMO these should certainly be given two distinct names.

    Secondly, since no one is offering the original Lo-Tech version (with integrated CF slot and bracket) in a prebuilt configuration, what would be the challenge for running a batch -- say 100 cards -- of the original design (with the bracket and integrated CF bay) and provide those to people who want the integrated design? Could a third party have permission to do so?

    Lastly, other than through-hole versus surface-mount assembly, what are the changes from LoTech's XT-CFv3 versus the Texelec version that is currently offered for sale from Texelec?

    Thanks!

    lotech_xt-cf-v3.jpg texelec-version-of-lotech_xt-cf-v3.jpg

  2. #2
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    I was a tester for the early Lo-Tech version. I assembled and programmed it myself with little difficulty, but then I had the Xilinx CPLD programming tool and software already. Surface-mount with traditional tools is easier than most people think.

    HOWEVER, the Xilinx XC9536-15VQG44C CPLD is no longer made, so you'll have to pick up any that you need on the spot/surplus market.

    I believe that Microchip/Atmel and Lattice still make 5V CPLDs, but of course, they aren't pin-compatible with the Xilinx part, so a PCB redesign would be necessary.
    Last edited by Chuck(G); December 27th, 2019 at 11:11 AM.

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    If you're just looking for a "pre-baked" board design that has a built-in CF slot and don't care about the CPLD vs. discrete TTL distinction you could run off a copy of Sergey's XT-CF-Lite V4:

    http://www.malinov.com/Home/sergeys-projects/xt-cf-lite

    There's also this card from monotech:

    https://monotech.fwscart.com/XT-CF_-..._19915453.aspx

    that "parasites" onto a commonly available pre-solded CF to 40 pin back panel adapter.

    Strictly speaking I think the schematics for all these devices are "open source" so if you want to make your own XT-CF I think you can; I'm unclear exactly what license is in play and personally I think it would simply be in poor taste to just run off a hundred copies of someone else's PCB design, markings and all.
    My Retro-computing YouTube Channel (updates... eventually?): Paleozoic PCs

  4. #4

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    Quote Originally Posted by Chuck(G) View Post
    I was a tester for the early Lo-Tech version. I assembled and programmed it myself with little difficulty, but then I had the Xilinx CPLD programming tool and software already. Surface-mount with traditional tools is easier than most people think.

    HOWEVER, the Xilinx XC9536-15VQG44C CPLD is no longer made, so you'll have to pick up any that you need on the spot/surplus market.

    I believe that Microchip/Atmel and Lattice still make 5V CPLDs, but of course, they aren't pin-compatible with the Xilinx part, so a PCB redesign would be necessary.
    Thanks Chuck for the feedback. I didn't realize the Xilinx XC9536-15VQG44C CPLD was no longer made.
    The XT-CFv3 (surface mount version) seemed to have the most features (DMA, slot 8 or not, zero-wait-state or not) built into it.

    I admit I'm just re-engaging from about 2012 when I bought a pre-built XT-IDE v2 with the 74-series logic. That particular board booted a few times, but on write it corrupted a few CFs, then corrupted its own BIOS when I tried to flash a newer version. So I shelved the project.

    There's a v4 of the original XT-IDE design (by Glitch works) but no completed-PCB available. One glitchworks v4 derivative (prebuilt) is available on ebay but there's no gold on the edge connectors, so who knows how reliable that would be in the long term. (See attachment)

    Does you have thoughts on longevity of those without gold edge-connectors? Just seems cheap to me (see attachment)
    glitchworks-v4-version-from-ebay-seller-hostnetone_resized.jpg

  5. #5

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    Thanks Eudimorphodon for those links! I now have more research to do on the ever-increasing amount of XT-IDE variants.

    Do you know if anyone here has experience with the monoTech variant you mentioned and if it supports DMA? I'm guessing not, but...

    Quote Originally Posted by Eudimorphodon View Post
    Strictly speaking I think the schematics for all these devices are "open source" so if you want to make your own XT-CF I think you can; I'm unclear exactly what license is in play and personally I think it would simply be in poor taste to just run off a hundred copies of someone else's PCB design, markings and all.
    Right, and this is why I was hoping James would chime in on what he feels would be the appropriate way to use his PCB design on a new batch run. However, as Chuck pointed out, this might involve a bit more work to source a batch of the original CPLDs.

  6. #6

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    Thanks Chuck and Eudimorphodon for your replies. I wrote 2 longer replies to each of you last night but they are still waiting moderation. In the mean time I'm able to post without moderation, so wanted to say thanks.

    Also, on a side note. I found an XT-IDE v4 (glitchworks derivative) on Ebay, but it did not have gold edge connectors. Any thoughts on reliability and long-term use of these types of boards that are not gold-plated?

  7. #7

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    Quote Originally Posted by LegacySystem View Post
    Thanks Chuck and Eudimorphodon for your replies. I wrote 2 longer replies to each of you last night but they are still waiting moderation. In the mean time I'm able to post without moderation, so wanted to say thanks.

    Also, on a side note. I found an XT-IDE v4 (glitchworks derivative) on Ebay, but it did not have gold edge connectors. Any thoughts on reliability and long-term use of these types of boards that are not gold-plated?
    Hate to break it to you but none of these XT-IDE cards have hard gold edge connectors like "real" ISA cards. The ones that appear to be gold are actually ENIG, which is both very soft and thin, and will wear off in a short number of insertion cycles.

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    I'll mention that it was a sad day when Xilinx dropped the XC95 5V series. I've still got a bunch unused, but given that there aren't any more made, I don't know what to do with them. Includes the XC95108 in 84 pin PLCC as well as the smaller ones.

    The 108s could be cobbled up to make a PCI interface.

  9. #9

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    Quote Originally Posted by maxtherabbit View Post
    Hate to break it to you but none of these XT-IDE cards have hard gold edge connectors like "real" ISA cards. The ones that appear to be gold are actually ENIG, which is both very soft and thin, and will wear off in a short number of insertion cycles.
    That's just what I was fearing and thus my idea for a custom run of PCBs that costs a few dollars more for a hardened gold surface. I'd rather pay $70 for a card that will last 10 years than $50 for something that oxidizes and/or otherwise is non functional in 3 years.

    I think that's a big problem with direction of current manufacturing (no matter what). Nothing seems not to be built for longevity anymore.

  10. #10

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    Quote Originally Posted by Chuck(G) View Post
    I'll mention that it was a sad day when Xilinx dropped the XC95 5V series. I've still got a bunch unused, but given that there aren't any more made, I don't know what to do with them. Includes the XC95108 in 84 pin PLCC as well as the smaller ones.

    The 108s could be cobbled up to make a PCI interface.
    That's interesting about the 108 being able to handle a PCI interface.

    Regarding the part you mentioned for the XT-CFv3, I found a few places online that still have XC9536-15VQG44C available. I wonder if it might be worth ordering a batch. I don't know how high the interest is in the community for additional stock of XT-IDEs with the CPLD design and the integrated CF slot. Maybe I'll put together a poll.

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