Re: Where to start on Missile Command PCB repair

Ok just one more quick clarification, when you are looking at a 74LS series
chip, they are both 10ns delays, the chips takes considerable less power to
operate, its not that it can't handle the voltage coming to the IC itself
right?

On Fri, Nov 1, 2013 at 9:31 AM, Kevin Moore <talon.k@gmail.com> wrote:

> I find Digikey tends to run a little higher on some things. I like Newark,
> Jameco, and occasionally Mouser.
>
> Also you can use Findchips.com they exclude Jameco but it will give you a
> good idea on pricing.
>
>
>
>
> On Fri, Nov 1, 2013 at 8:27 AM, Grant Thienemann <
> grant.thienemann@gmail.com> wrote:
>
>> Hey Kevin,
>>
>> Thank you for the information! I've never used Jameco before, I've always
>> used digikey.
>>
>> -Grant
>>
>>
>> On Fri, Nov 1, 2013 at 9:26 AM, Kevin Moore <talon.k@gmail.com> wrote:
>>
>>> 74S00
>>>
>>> http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_676959_-1
>>>
>>>
>>>
>>> On Fri, Nov 1, 2013 at 8:24 AM, Grant Thienemann <
>>> grant.thienemann@gmail.com> wrote:
>>>
>>>> Ok lets say you have a 74S00, which is for speed, can you replace that
>>>> with a 74F00?
>>>>
>>>>
>>>> On Fri, Nov 1, 2013 at 9:17 AM, Grant Thienemann <
>>>> grant.thienemann@gmail.com> wrote:
>>>>
>>>>> Hey Rodger,
>>>>>
>>>>> Thank you for the information. I'm looking at wikipedia now about the
>>>>> 74XX series chips, which would be the default standard when looking to
>>>>> replace a 7400, or 7404 etc, would that be HTC?
>>>>>
>>>>> Thanks
>>>>> Grant
>>>>>
>>>>>
>>>>> On Fri, Nov 1, 2013 at 9:08 AM, Rodger Boots <rlboots2@gmail.com>wrote:
>>>>>
>>>>>> Close. HCT is closer. Either should work.
>>>>>> On Nov 1, 2013 7:52 AM, "Grant Thienemann" <
>>>>>> grant.thienemann@gmail.com> wrote:
>>>>>>
>>>>>>> Ok not to keep getting off topic, but as this is related to the
>>>>>>> Missile Command repair, I'm going to ask. When I look for 74191 I can't
>>>>>>> find anything on Digikey, etc, but when I search for 74HC191 it comes up,
>>>>>>> is that the same thing?
>>>>>>>
>>>>>>>
>>>>>>> On Fri, Nov 1, 2013 at 8:42 AM, <solarfox@triluminary.net> wrote:
>>>>>>>
>>>>>>>> On Fri, 1 Nov 2013 00:35:07 -0400, you wrote:
>>>>>>>>
>>>>>>>> >So I can generally replace a 7404 with a 74LS04 without any
>>>>>>>> problems?
>>>>>>>>
>>>>>>>> *Normally*, yes, but there *are* cases where you can run into
>>>>>>>> problems. The
>>>>>>>> switching speed of 74LS-series parts isn't *quite* identical to
>>>>>>>> standard
>>>>>>>> 7400-series; the propagation delays of a 7404 vs. a 74LS04, for
>>>>>>>> example:
>>>>>>>>
>>>>>>>> -------- 7404 -------- ------- 74LS04 -------
>>>>>>>> tPLH 12ns (typ) 22ns (max) 9ns (typ) 15ns (max)
>>>>>>>> tPHL 8ns (typ) 15ns (max) 10ns (typ) 15ns (max)
>>>>>>>>
>>>>>>>> (Source: a very dog-eared and well-used copy of "The TTL Data Book,
>>>>>>>> vol.2",
>>>>>>>> Texas Instruments, 1985)
>>>>>>>>
>>>>>>>> The difference is, admittedly, pretty small, but it can add up when
>>>>>>>> you've
>>>>>>>> got signals flowing through a bunch of different gates, or when
>>>>>>>> you've got
>>>>>>>> a more complex chip (such as the 74191). So, depending on the
>>>>>>>> circuit in
>>>>>>>> question, there's a small (but non-zero) chance that you *could*
>>>>>>>> end up
>>>>>>>> with a "race" condition by swapping a 74LS part into a circuit full
>>>>>>>> of
>>>>>>>> 7400-series chips.
>>>>>>>>
>>>>>>>> --------------------------------------------------------------------------
>>>>>>>> "I thought I told you to look after him!"
>>>>>>>>
>>>>>>>> "He'll be all right; he's a Time Lord."
>>>>>>>>
>>>>>>>> "That's just what they're _called_; it doesn't mean he actually
>>>>>>>> knows what
>>>>>>>> he's _doing!_"
>>>>>>>>
>>>>>>>> --------------------------------------------------------------------------
>>>>>>>> solarfox@triluminary.net (Gary
>>>>>>>> Akins jr.)
>>>>>>>>
>>>>>>>> --------------------------------------------------------------------------
>>>>>>>>
>>>>>>>>
>>>>>>>> ---------------------------------------------------------------------------
>>>>>>>> ** Unsubscribe, subscribe, or view the archives at
>>>>>>>> http://www.vectorlist.org
>>>>>>>> ** Please direct other questions, comments, or problems to
>>>>>>>> chris@westnet.com
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>
>>>>
>>>
>>
>

---------------------------------------------------------------------------
** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org
** Please direct other questions, comments, or problems to chris@westnet.com
Received on Fri Nov 1 09:32:52 2013