Moving from 74 series to 4000 series

[ericgibbs]

Agreed, I think point was not that logic design is obsolete, rather certain logic families are.

hi Mike,
The word 'obsolete' in my understanding is, no longer in production, not that they will no longer do the job for which they were originally designed.

Like many other members I have lots of these 'obsolete' devices in stock and if they meet the project specification, I will use them.

As we are lucky enough to live in countries which have all the latest technology available, we tend to forget others are still having to use 8051, 741, TTL555's and the old 74xx ic's.

Also there is still a lot of operational equipment in the field using this old technology.

 

[rmn_tech]

Do you have a link to the PIC ESR tester? It's something I always wanted to play with.

Hi Blueroom I found this one ages ago but forgot all about it. I haven't even really looked at it yet.

I would value your opinion on this as to whether it is worth a build.

**broken link removed**

 

[ericgibbs]

Hi Blueroom I found this one ages ago but forgot all about it. I haven't even really looked at it yet.

I would value your opinion on this as to whether it is worth a build.

**broken link removed**

hi rmn,
Another OP posted this last year, IIRC it was a disaster.

It turned out to be theoretical project and was written as a submission for a college/univ project.

 

[Mikebits]

hi Mike,
The word 'obsolete' in my understanding is, no longer in production, not that they will no longer do the job for which they were originally designed.

Like many other members I have lots of these 'obsolete' devices in stock and if they meet the project specification, I will use them.

As we are lucky enough to live in countries which have all the latest technology available, we tend to forget others are still having to use 8051, 741, TTL555's and the old 74xx ic's.

Also there is still a lot of operational equipment in the field using this old technology.

If you have them in your toolbox, then buy all means use them, I am not saying they are bad or anything like that at all. What I am saying is that certain parts have reached end of life, and will no longer be manufactured in the near future. This is not to say stop using them, rather one should be aware of impending doom and expect supply to soon be cut short. For new designs, one should look at newer technology, but use what you can get. Like it or not the 4000 series will soon become unavailable, it is good idea to update the antiquated websites that continue to promote old tech designs.

I merely supported DIY's supposition that 4000 logic is old technology which it is. We no longer need the wide volt range of 4000 logic as more battery friendly technology is now available. This does require a cross discipline of knowledge to overcome the multiplatform of technology.

 

[BrownOut]

Boy did you miss the point entirely. The tools and techniques of logic design were never the point of the discussion. The specific realization of a design with the original TTL parts (74xx) or the original 4000 series parts was the point. I would have no argument with a hobbyist making one of anything with any part he could lay his hands on. Trying to make a bunch of something with obsolete parts is, in my opinion, quite risky. Many of those parts are quickly becoming pure unobtainium not to mention gray market counterfit.

I guess you would have to read the entire thread to understand why these comments are relavant, especially comments like this:

On the other hand, I have hundreds and hundreds of TTL, CMOS and analog chips less than ten feet away. Why not use the stone and wooden wheels I have on hand rather than make a trip to Moe, Manny and Jack's for steel wheels and rubber tires (and the equipment needed to mount them)?

And then put these comments into the context of the many, many other discussions we've had on this subject. But then again, I'm proabaly expecting too much.

 

[rmn_tech]

hi rmn,
Another OP posted this last year, IIRC it was a disaster.

Cheers, As I said I've not really examined the project. It seems that you may have saved me some time and heartache.

 

[Dean Huster]

On this subject, I'm always coming from the point of being able to use what you have and can get inexpensively rather than running out a buying the latest and greatest. If it's a "one-off" project just for you, use whatever you want. If you want to experiment with the newest stuff, by all means buy the processors, programmers and software to do it. If you're designing something for production, don't you dare use anything but what's in popular use, but don't necessarily use something that's cutting-edge as it can be still too-expensive and not fully proven. A product has to be cost-effective to produce and if it's a high-end product, it has to be reasonably repairable.

With the automotive analogy, for my own private use, I'll go out and buy a 1980 Chevy LUV in good condition for what I need to do rather than a new 2010 Hummer H2. On the other hand, if I'm needing fleet vehicles for my home medical business, I'm going to by inexpensive NEW vehicles to keep costs low and reliability high.

I'm not that interested right now in spending my time with processors. I'd rather design and build analog and digital circuits using the old stuff. And yes, I do like vacuum tubes, too, limited to "antique" test equipment and radio restoration -- not new construction for production -- although audiophools do offer quite the tempting market for such things!

Dean

 

[colin55]

Further to Dean's comment, I notice he wrote for Poptronics, and he will understand the following comments.
It is a pity Poptronics "went down the tube" as I connected with it during its last 8 months and contacted Larry Steckler with the suggestion to improve the magazine by including it on the web and providing modules with each issue.
He was very hard to reach but I eventually created a web edition and suggested a surface-mount PIC chip on a prototype board for all sorts of simple projects as well as lots of other projects that would be included “free” with each issue.
The only hold-back at the time was the programmer and I was working on a very simple design using the USB port and a few components, when I found out the January issue was not printed!!
No-one was told of the demise!!
I produced a magazine in Australia some 5 years before the demise of Poptronics and it was the first in the world to provide circuit boards on the magazine with overlay and the availability of a kit of components to finish the project. I used this experience to expand the concept for Poptronics. If I had known Poptronics was about to dissolve, I would have bought the company as it had enormous potential. It was simply poorly run. Larry Steckler was not an electronics person and was not interested in the advancement of electronics.
He let thousands of people down by pulling the plug and it’s unfortunate that all the prototypes I created for future issues, have laid dormant since the demise.
One of the kits was a Stirling Engine and you can imagine the interest that would have created.
So many of the kit magazines have folded, along with the components shops, that the only thing left is the possibility of a web-based magazine that backs up articles with kits of parts.
But since advertising revenue would be minimal, the possibility of attracting writers would be difficult and the whole thing spirals into itself.

 

[BrownOut]

I agree w/Dean Huster. Sort of what I've been saying all along. I advocate digital logic for expimenters often. But not only because I'm a romantic, but as I've pointed out, understanding logic is still very relevant in the modern world. How many people show up in here and aren't able to describe what a transistor or a logic invertor does? These are still important concepts, and every hobbist or engineer needs to know these things, as well as microcontrollers.

And, if you want to do logic design with modern methods, use CLDP's and FPGA's and design in HDL.