[sci.electronics] TMS3450

mleech@bcarh342.bnr.ca (Marcus Leech) (06/07/90)

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

ken@swbatl.sbc.com (9081) (06/08/90)

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-