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From: ken@swbatl.sbc.com (9081)
Newsgroups: rec.ham-radio,sci.electronics
Subject: Re: TMS3450
Keywords: clock-chips silicon texas-instruments brain-death
Message-ID: <1569@swbatl.sbc.com>
Date: 7 Jun 90 21:00:12 GMT
References: <1990Jun7.141107.6790@bnrgate.bnr.ca>
Reply-To: ken@swbatl.UUCP (Ken Gianino 5-9081)
Organization: Southwestern Bell Tele. Co. - Advanced Technology Lab - St. Louis
Lines: 33

In article <1990Jun7.141107.6790@bnrgate.bnr.ca> mleech@bcarh342.bnr.ca (Marcus Leech) writes:
>
>A couple of years ago I bought a Radio-Shack 24-hour digital clock
>  with a *BIG* display.
>Radio-Shack stopped selling this beast, but a local discount
>  store is offering a remarkably similar clock that only
>  provides 12-hour display.  It turns out that they both use
>  the same display, and electronics--namely the TMS3450
>  clock chip.
>I tried to get information out of Texas Instruments on this chip,
>  but they steadfastly refused to acknowledge its existence.
>  The chips have the TI logo on them, and they use the TMS
>  numbering scheme characteristic of TI.
>Can anybody (TI, are you listening??) give me any information on this
>  chip--I would like to modify the twelve-hour version of the clock
>  to twenty-four.  I almost have it, but I need some info about the
>  chip.
>-----------------
>Marcus Leech, 4Y11             Bell-Northern Research  |opinions expressed
>mleech@bnr.ca                  P.O. Box 3511, Stn. C   |are my own, and not
>VE3MDL@VE3JF.ON.CAN.NA         Ottawa, ON, CANADA      |necessarily BNRs


    Here's a brief note about converting those 12 H LED clocks to 24 H. I
    was going to buy a Radio Shack 24Hr clock untill I noticed a local
    discount store had the exact same clock (less the 24/12Hr switch) for
    about $5. It didn't take too long to figure out the little solder pads
    for the options (12/24Hr and 50/60 Hz). Lo and behold, when I turned it
    on I discovered that the LED display had only enough segments for 18:88.
    They actually left the other led's off the display module! It does still
    work, though.

    Ken -WB0QNA-