|Re: To Ellis: maybe not easy, but...|
Message #3 Posted by glynn on 8 Apr 2003, 10:01 p.m.,
in response to message #2 by Ellis Easley
Thanks much for the appreciation. One thing that I *wished* to convey as I wrote was: that everything involved in making a workable substitute display was NOT magic, but DO-ABLE.
Oh, I was stupid in suggesting that somebody out there likely still made the parts. They CAN, of course, but apparently decided the market did not support making such a bird and keeping any stock of it. (I imagine Agilent, at the time they pared their parts catalog, never suspected that calculator COLLECTORS would exist to look for such things.)
I myself hadn't suspected that HP was using a design in their displays that was so deviant from the layout of OTHER seven-segment displays that it would make a difference in how the device using it sent the information to be displayed (the decimal point requiring a full digit-space).
And I plainly muffed it when I thought that somebody would still be making a seven-segment display so small (ha!! and I thought .2" WAS small!!), when about the only manufacturers that would care to buy such a product would be calculator makers, who had abandoned LED displays for LCD long ago. (The main advantage of LCD of course is its low power requirements, making LED seem way too hungry and wasteful.)
So, the simple, easy method of component replacement is no longer available, unless we stumble into a box in some old dusty warehouse, with long-overlooked tray upon tray of 5082-7405s. It could happen. Still worth looking out for.
So much for the "easy way". I wrote about the possibility of a more complicated option, and maybe ended on too skeptical a note, primarily because in my mind, the economics of it were poor as an "enterprise", even considering the eBay price of Classics. But economics can change, and even such a "Frankenstein" display as my proposal might SOMETIME be worth doing, should fully-working Classics be so desired that collectors begin to seek extra-HP solutions.
But I intended to point out that while what HP produced was a showcase example of their technological superiority (as most everything they produced back then WAS-- they showed off because they got business that way, and because THEY COULD do what others often couldn't!), that you could still investigate, understand and finally, replicate the result, if not the elegance, of the original.
Some of the tools and the tech once available only to a major concern such as HP are now the realm of small organizations in your hometown.
Agilent may still possess vast powers of "magic", but while once upon a time you'd have HAD to build your own LEDs from raw chemicals and using arcane processes to layer and etch a wafer that, hopefully, would emit light at the end of it all, NOW there are companies willing to sell you the bits and pieces that can, with some toying around, be cobbled into what you need.
These days ARE different, and though true "magicians" will always be at the sharp bleeding-edge, doing what we can't, there are a lot of good, underutilized, underemployed techies, possibly some with kit they bought at bankruptcy auction, and they've worked on the factory floor, seeing what steps get you where. Technology "booms" and "busts" do something useful; they spread last year's models around and take suppliers' smug disapproval of dealing with small businesses down a peg.
There are design and automation tools that would really have BEEN "magic" only a few years ago. There's the internet, which allows us to bounce around techniques past all, from professional to tinkerer. There are businesses whose mission is to support and supply esoteric materials to "the rest of us". There is a lot of business devoted nowadays to providing and supporting various scales of production. And stuff that makes production work efficiently often has the effect of making entry-level, minimum-wage workers able to take over tasks that once required extensive training.
So, while I agree that some of what I described sounds daunting, and it IS a lot easier NOT to do it if you don't absolutely HAVE to, nothing I've described would be impossible (or even improbable) for one who was looking for the way to get the job done.
Heck, you can RENT the equipment to produce wire bonds and drop glue down and encapsulate in epoxy and cure it-- in any reasonably-sized city in most places in the world, a trip to the phone-book will find the resources needed to get the job done. You can MAKE it more complex than is absolutely necessary-- and sometimes you'll want to, when it would make the work go faster, easier, more fruitful.
But Ellis, in about two hours peering down the microscope, making practice wire-bonds and testing them, you'd have the technique pretty well down. You'd be on your way to making a display, one segment at a time.
Placing the right-size drops of glue and getting the die right side up and in the spot you want them to be-- if you can play video games reasonably well, you can be a pro at this WITHOUT a degree or years invested in learning all about it. It is developed and applied technology now, and whether doing it one die at a time with micro-tweezers or going someplace where they do it a hundred times faster with automated suction placement gear, it's NOT "rocket science" and not any more complex than the same equipment used in many modern medical labs for automated sample testing.
That's why I looked at this way of doing it: making your own GaAs wafers (usefully) is a bit beyond the "lone techie" or the small club without a couple of years and a fortune to waste; but "hand" assembly of an array of die sourced from a carefully controlled wafer-fab IS WITHIN REACH, if the economics make sense enough to make it worth your while.
So, if enough owners of HP "Classic" calculators want for displays, and they want them BAD enough to pay for the costs, and a techie wants to shepherd the process and make this his "project", it CAN be done. Without running to Agilent and begging on your knees. Without a lot of silicon-doping and vapor-deposition and advanced chemical knowledge. Without building an empire of technical, marketing and financial genius.
I once watched, and marvelled at the sheer madness involved, as a friend of mine molded, carved upon and painted, using the tiniest of brushes, a small part of a model-railroad station. Using bright lights and magnifying glasses, lilliputian details were sculpted and finished to the point where, using a camera with a macro lens, you would swear you were there. Signs advertised on the wall, and they were fully readable and professional. The figures wore plaid and denim and had hair and pearlescent buttons on their shirts and real, rosy expressions on their faces. The wood all had grain and was weathered. A rocking-chair was poised ready to tread on the tail of a peacefully-napping dog. Norman Rockwell would have been proud to have portrayed such a scene, if only Mr. Rockwell had been about 80mm tall. My friend used dental tools and picks and almost daily made revisions and reworked some part of it, gradually bringing the scene closer to his vision of what the passengers of his train would see as it pulled in to this station. The engine and train of cars was equally painstakingly detailed.
I had always thought that you just bought some machine-made, pre-printed station, plunked it down beside a pre-built track, and ran a pre-built train past it. Seeing this little diorama evolve over a couple of years, I had to admit: hobbyists and enthusiasts can be stark-raving nuts, yet what they can do when they are totally involved in their passion is astounding and admirable.
What someone determines if it is worth doing? Only the do-er.
But many things I would not have thought do-able on a limited budget and within a reasonable time have BECOME so, for both corporations and individuals who still strive to create.
Take care-- g.