OT - 40 years of 5 volt TTL logic

It occurred to me that it's been 40 years to
the month since I wired together my first
TTL circuit. Hard to believe its still around.

Hi Jim,

On 10/12/2011 10:12 AM, Jim Stewart wrote:
> It occurred to me that it's been 40 years to
> the month since I wired together my first
> TTL circuit. Hard to believe its still around.

<grin> I get annoyed at how much "tarnish"
accumulates on the pins over the years...

("Time to go polish the TTL...")

On Wed, 12 Oct 2011 10:12:04 -0700, Jim Stewart
<> wrote:

>It occurred to me that it's been 40 years to
>the month since I wired together my first
>TTL circuit. Hard to believe its still around.

That would be about right for me, too! I think that was the
year, 1971, when I got my TI databook on the 7400/5400
series.

And yes, TTL in the form of LS, S, AS, ALS, and F still
survives. Does anyone still use/provide the original?

not to mention ... AC, ACT, HC, HCT, AHCT ...

Jon

On Wed, 12 Oct 2011 10:12:04 -0700, Jim Stewart wrote:

> It occurred to me that it's been 40 years to the month since I wired
> together my first TTL circuit. Hard to believe its still around.

It occurs to me that I just used a knife to cut a frayed end off of a
belt that I'm resizing.

Some technologies do persist, TTL logic has a way to go before it 'edges'
out blades.

--
www.wescottdesign.com

On Wed, 12 Oct 2011 10:18:24 -0700, Don Y <>
wrote:

>Hi Jim,
>
>On 10/12/2011 10:12 AM, Jim Stewart wrote:
>> It occurred to me that it's been 40 years to
>> the month since I wired together my first
>> TTL circuit. Hard to believe its still around.
>
><grin> I get annoyed at how much "tarnish"
>accumulates on the pins over the years...
>
>("Time to go polish the TTL...")

Now that is funny and so true!

Jon

Jon Kirwan <> writes:

> On Wed, 12 Oct 2011 10:12:04 -0700, Jim Stewart
> <> wrote:
>
>>It occurred to me that it's been 40 years to
>>the month since I wired together my first
>>TTL circuit. Hard to believe its still around.
>
> That would be about right for me, too! I think that was the
> year, 1971, when I got my TI databook on the 7400/5400
> series.
>
> And yes, TTL in the form of LS, S, AS, ALS, and F still
> survives. Does anyone still use/provide the original?

Seems to be still widely available - and in use too by the look of it!

<http://www.findchips.com/avail?part=sn7400>

> not to mention ... AC, ACT, HC, HCT, AHCT ...

HC is still very useful. I still design it into new products. 74HC595
and 74HC165 are unbeatable as low cost "I/O expanders", converting 3
microcontroller pins into an unlimited number of switched I/Os at
negligible cost.

The Tinylogic style single gates are useful as "non-logic" components
too, especially in the newer families like LVC, AUP. I use them for gate
drivers, oscillators, PWM circuits etc.

--

John Devereux

On Oct 13, 6:12*am, Jim Stewart <jstew...@jkmicro.com> wrote:
> It occurred to me that it's been 40 years to
> the month since I wired together my first
> TTL circuit. *Hard to believe its still around.

- and 5V is making something of a come back too
Wide supply is now common to see, not just in Logic, but also in
Microcontrollers and RAM.

Of course, you can also grumble about how LITTLE TTL/CMOS series
devices have changed, and how generic standards lock us into generic
parts.

As an example, I was looking for a simple, selectable divider
recently.
Sadly, because the original 4020/40/60 designer did not think of
adding a Mux, no one has done so since...

-jg

John Devereux wrote:
> Jon Kirwan <> writes:
>> And yes, TTL in the form of LS, S, AS, ALS, and F still
>> survives. Does anyone still use/provide the original?
>
> Seems to be still widely available - and in use too by the look of it!
>
> <http://www.findchips.com/avail?part=sn7400>
>
>> not to mention ... AC, ACT, HC, HCT, AHCT ...

It's the latest thing with the kids:
<http://dangerousprototypes.com/category/7400-contest/>

Mel.

Jim Stewart wrote:

> It occurred to me that it's been 40 years to
> the month since I wired together my first
> TTL circuit. Hard to believe its still around.

It made a nicer, more compact product than the Mullard Norbit I was using
before moving over to TTL (probably around the same time as yourself).
Before Norbit we had discrete RTL circuits. Aahhhhh; Memories!!!!

--
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On 13-Oct-11 4:12 AM, Jim Stewart wrote:
> It occurred to me that it's been 40 years to
> the month since I wired together my first
> TTL circuit. Hard to believe its still around.

I remember when we got a device in 1974, and it was marked with batch YearYear/WeekWeek, you could end up with for
example, a 7406 marked 7406 twice because of the naming and batch convention.

many a wrong IC was selected by newbies who didn't understand.

Cheers Don...

===============


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Don McKenzie

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