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Thread: Apple II keyoard encoders

  1. #1
    Join Date
    May 2006
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    Hamilton, Ontario, Canada
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    Default Apple II keyoard encoders

    Hi,

    I have a purchase decision to make and I'm looking for input here.

    I already have sourced and am expecting delivery of some of each of the following NOS chips;

    SMC KR3600-070
    GI AY-5-3600-PRO-050
    SMC KR3600-017-PRO
    SMC KR9600-PRO
    GI KB3600-PRO

    The problem is that I have also sourced the non-encoder board encoder MM5740AAE/N, which are socket pulls, but are considerably more expensive than that other encoders. Is there enough of a market for me to bother getting these particular chips?

    MM5740AAE.jpg

    Thanks
    Legacy Computers and Parts

    Sales of, parts for, and repairs to, Vintage and Legacy computers.

  2. #2
    Join Date
    Dec 2011
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    Default

    If the MM5740 chips work then yes there is a market. I’d be willing to buy a few if they do work. I have bought plenty that don’t.

  3. #3
    Join Date
    May 2006
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    Default

    Quote Originally Posted by Corey986 View Post
    If the MM5740 chips work then yes there is a market. Iíd be willing to buy a few if they do work. I have bought plenty that donít.
    As you can see, it is the MM5740AEE/N which is said to be the only one that WILL work in the Apple II/II+
    Each of them will be tested in an Apple II+ with a Rev. 4 motherboard and a (what appears to be) later second version Datanetics keyboard.
    We're big on testing things before selling them.
    The other keyboard encoder are going to go for about $20 CAD (plus shipping), regardless of make or model number, but the 5740AAE/N will be closer to $40 CAD (plus shipping), so about twice the price. Selling them for less wouldn't be worthwhile.
    I'd rather not end up with a bunch that won't sell or that I have to sell at a loss.
    You see why I'm seeing if there is a market.
    Legacy Computers and Parts

    Sales of, parts for, and repairs to, Vintage and Legacy computers.

  4. #4

    Default

    Number of things in this thread I may be reading incorrectly ....

    The idea that only the MM5740 will work in a II/II Plus is not accurate unless there's some context added to the statement. The non-encoder board based keyboards - yes, only the MM5740 will work on these keyboards, particularly the Version 1 and Version 2 keyboard models. The later keyboards that use encoder boards - the MM5740 will not function.

    It is also somewhat dangerous to purchase GI and SMC encoders unless they've been tested in an Apple product. I've seen many sold on eBay that were never programmed. If they're not programmed, you cannot program them unless you use proprietary methods to program them. Even if they're already programmed, the part numbers are 3rd-party, and are not specific to just the Apple II. There's a chance that the exact same part number of an encoder may be programmed with a different key matrix, and you'll find that out when you, for example hit the letter "A" and it outputs a "J" or something else.

  5. #5
    Join Date
    May 2006
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    Hamilton, Ontario, Canada
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    Default

    You have a semi-valid point.
    I mentioned in the first post in the thread "also sourced the <B>non-encoder board encoder</B> MM5740AAE/N".
    Since we are talking about non-encoder board encoders, that, pretty much, eliminates all the keyboards that have separate keyboard encoder boards, wouldn't you say?
    The fact that I listed the equipment that they would be tested on, and since the second version of the Datanetics keyboard doesn't have a separate encoder board, it should have been a clue to which II/II+ models I'm talking about.
    In such keyboards, as far as I know, the AEE version of the 5740 IS the only version of the chip that will work right.
    In regards to the SMC and GI encoders, you see the prefixes on the chip numbers? Those ARE the ones designated as the correct numbers for the Apple II/II+/IIe/IIc and Laser 128 non-ex version (seeing as the EX uses a 4048 for the keyboard).
    The prefixes indicate which computer the chip has been programmed for.
    We actually did give this some thought and research prior to ordering....
    This is a business and we don't buy a pig in a poke..
    My supplier, someone I trust, sent us a dump of the code of a representative chip of each type which we compared to a dump from an actual production chip. Had they not match, we wouldn't have purchased them. They will also all be tested in the appropriate computer and run through the Apple Dealer Diagnostics, XPS and Apple-cillian keyboard tests for the appropriate model.
    Is that sufficient due diligence for you?
    We are in the business of supplying the correct part/equipment for our client's systems and if this doesn't set your mind at ease, then I would suggest that you don't purchase any of them.
    Legacy Computers and Parts

    Sales of, parts for, and repairs to, Vintage and Legacy computers.

  6. #6

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    Wow, looks like someone woke up on the wrong side of the rock.

  7. #7

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    Your topic reminds me I am still looking for this http://www.vcfed.org/forum/showthrea...ard&highlight=

    What programmer are you using to read and compare dumps of your encoders?

  8. Default

    Be careful testing the MM5740, many have intermittent failure signatures, they start generating characters without a keypress only after they warm up. I spent some time trying to determine if there was some kind of keyboard design issue that might cause this, but could find no cause.

    I haven't tried them, but I believe the AAF should also work, as the difference between the AAE and AAF is additional support for N-key roll-over on the AAE chip and the Apple keyboards that use this chip don't support N-key rollover anyway - the keyboards are lacking the needed diodes.

    A source of proven working MM5740's would be helpful to the collector community, as these chips tend to be sensitive to static discharge, especially the ones in the first model keyboards.

    regards,
    Mike Willegal

    Quote Originally Posted by Druid6900 View Post
    As you can see, it is the MM5740AEE/N which is said to be the only one that WILL work in the Apple II/II+
    Each of them will be tested in an Apple II+ with a Rev. 4 motherboard and a (what appears to be) later second version Datanetics keyboard.
    We're big on testing things before selling them.
    The other keyboard encoder are going to go for about $20 CAD (plus shipping), regardless of make or model number, but the 5740AAE/N will be closer to $40 CAD (plus shipping), so about twice the price. Selling them for less wouldn't be worthwhile.
    I'd rather not end up with a bunch that won't sell or that I have to sell at a loss.
    You see why I'm seeing if there is a market.

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