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Thread: XT-IDE 74F573 latch recommended?

  1. #1

    Default XT-IDE 74F573 latch recommended?

    On the XT-IDE BOM, the latches are listed as 74F573, but the board shows 74LS573. An F latch is a lot faster - does it provide extra safety margin timing wise?

    I went with 74HCT573 latches so far - I had those...

    I got this far - now I have to order parts

    XT-IDE_nearly_complete.jpg

    I assume the DDR gates will provide me with twice the speed?

    XT-IDE_DDR.jpg

  2. #2
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    I doubt that it makes much difference in most cases. IIRC, the original XT-IDE used LS373 latches.

    I've wondered myself if the XT-IDE could be re-done using a 74LS646 bus register. Probably--but with no real savings in components. Really, the answer is in programmable logic (CPLD), but sources for 5V units have pretty much dried up.

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    Quote Originally Posted by Chuck(G) View Post
    I doubt that it makes much difference in most cases. IIRC, the original XT-IDE used LS373 latches.
    Indeed, it can be LS or HCT family. I was using 74F573s for a while since they were significantly cheaper from one of my usual suppliers (they had several hundred in stock).

    Quote Originally Posted by Chuck(G) View Post
    I've wondered myself if the XT-IDE could be re-done using a 74LS646 bus register. Probably--but with no real savings in components. Really, the answer is in programmable logic (CPLD), but sources for 5V units have pretty much dried up.
    Yeah, level shifting to a 3.3V CPLD is the "real answer" for getting away from discrete TTL, but it'd significantly reduce the hobbyist-friendly nature. I don't know if it'd really be any cheaper parts-wise, with the proper level shifters.

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