In design obsolescence creeps up on us slowly.

Finally, after pining for more than a few years, I had my first experience running a CAD system in 1985 using a general-purpose tool that arrived on two or three 360k floppies called AutoCAD. Amazingly this tool still sells in a present-day 130 Meg Windows incarnation, although now far less robustly than in the days when people used AutoCAD to design almost anything -- including PCBs, which is how I got started laying out boards using a computer.

My first "CAD computer" was an NEC APC III ...an 8 Mhz 8086 90% clone of an IBM PC. It had a 10 Meg hard drive, 640k of RAM and proprietary 640 x 400 pixel 256-color graphics ...far better graphics than the standard IBM-PC "CGA" color adapter which had you squinting at an array of 320 x 200 pixels and only 4 colors (unless you wanted to pay a few thousand bucks for IBM's "PGA" card at 640 x 480, or re-mortgage your house for a "8514" board and compatible monitor at 1024 x 768).

Today, by comparison, my PC displays at 1600 x 1200 pixels with millions of colors on an 18-inch dead flat monitor from ViewSonic that cost me less than $500. At 600 MHz, the CPU is 80 times faster than the NEC, at 128 megs it has 250 times as much RAM, and the disk drive can hold 1000 times more data than the "huge" Seagate 30-meg drive upgrade that cost me 800 bucks in 1986 (the price of an entire home-office PC today adjusted for inflation). If not for Bill Gates and company, I might even notice that this machine is a little bit faster than my old NEC.

But even at a high price by today's standards, buying a PC for design work in the 1980s was still worth every penny because of how AutoCAD was a great improvement over designing anything with a pencil. Just being able to move or rotate whole chunks of my drawing, instead of erasing and re-drawing by hand (or playing games with a photocopier) doubled my productivity overnight. Yet AutoCAD could only let you control things like lines, arcs and circles. Without special proprietary add-on software for PCB design, AutoCAD did not understand that certain lines needed to be connected to certain circles ...but I made do, because there wasn't any other real choice in that price range.

By the later 1980s, however, the DOS PC revolution was well under way. IBM's VGA graphics were finally standardizing the DOS GUI wild west at 640 x 480 (acceptance of SuperVGA was still a few years out), and as a result dedicated DOS programs for designing PCBs began to become widely excepted.

One of the first of these PC-based PCB design tools was a nearly full-featured package of programs called P-CAD created in California by a colleague of mine named Rich Nedball. Finally here was a system that almost any company could afford, and it did the job with far less aggravation than the old 200-thousand-dollar dinosaurs running on a VAX. But nothing lasts forever. For a time in the late 1980s P-CAD owned more than half the market for PCB design seats worldwide. Today almost nobody runs it anymore.

So this morning I tossed out my old P-CAD manuals. Except for some sentimental value, there was no need for these binders to collect dust anymore. I design with a new tool called Pads PowerPCB with documentation on a searchable CDROM. Pads PowerPCB is now the tool to beat (In fact, Rich Nedball now runs a division at Pads), but I expect that one day PowerPCB will itself be replaced by an even newer incarnation, by Pads or by somebody else.

During the move, I also pitched out several file drawers worth of documentation ...obsolete designs that are no longer being produced. And as I spent a brief few moments rummaging through this thick stack of folders I realized that these files should have been pitched out a long time ago. (In fact, I also got rid my file cabinets just so I never do this to myself again!) But I am saving a few samples from the pile as milestone reminders.

Now, as I settle into my new office and lean back in my new chair with the smell of fresh carpet in the air, I observe an impromptu table I assembled in here with one end held up by an old PC chassis set on its side. Since the NEC is long gone, perhaps it's the screaming 386-20 I bought in 1988 for $3,000 and stopped using in 1992, but I'm not entirely sure. One thing I am certain of though ...my current PC is a tower configuration which I expect will come in handy in a few years when I need another table leg or something solid on which to perch when painting the ceiling the next time I move ...especially if Bill Gates and company(s) has his bloated way.