DEAR BOB,

That Electronic Design article “What’s All This Microsoft Stuff, Anyhow?” was delightful—brought a big smile to my face. I’ve been with AOL for 14 years, and have encountered a number of problems in that time, but consider myself lucky in that most were rather trivial. Now, McAfee, that’s a different story. I hate the way it sneaks in and overpowers whatever you are doing. (Uh, yeah... /rap)

Yesterday, McAfee turned on while Retrospect was doing its daily backup of my files. Normally when another program interferes, it just slows down the operation. This time, even the time display of hours and minutes was stalled to show the time two hours earlier when the backup turned on. The computer was frozen, immovable, unreachable, and had to be reset to reboot. That kicks Retrospect into a never-start mode, and I had to intervene and “manage my scripts” today to get it onto automatic mode again. But McAfee is free, included with the AOL service, so I guess I’ll keep it. (“Free,” aha, but not without terrible cost. /rap)

In another room, I have an old 80386 computer running on Windows 3.1, with no connection to the Internet and no need to have an antivirus program. It’s so reliable, it’s wonderful—boots up in about 30 seconds. It contains two PCL-812 data acquisition cards that I use to run testing on a small consumer electronics product that I designed. It’s nice to have something you can depend on. Those cards are twice as long as could be contained in any modern computer. And the computer can even read a 5.25-in. floppy disk!

Speaking of old things, did you ever have any experience with a GEDA analog machine? I can’t say computer because it wasn’t programmable except through patch cords. It was a Goodyear Electronic Differential Analyzer, with about 20 high-gain amplifiers that could be configured into very respectable integrators, since they were serviced by a rotary sampling switch that looked at all the amplifiers’ input terminals in sequence and fed an amplified correction signal into the rebalancing inputs to make the voltage close to zero at the inputs. It was a rotating chopper-stabilized amplifier system. There were also one or two analog multipliers included with the system for doing nonlinear stuff.

In my first job out of Cornell in 1953, I kept popping into the lab out of curiosity where the GEDA was supposed to be working, but it wasn’t. That was at the General Electronics Advanced Electronics Center near the airport in Ithaca, N.Y., which was also a relic of the past. (I never saw, nor worked on, or heard much about the GEDA. /rap)

I got it working and stayed on call in case the lab needed any further assistance. Whenever the system became unstable or went out of limits where the rotary chopper couldn’t handle the signals, relays were triggered that acted as some sort of crowbar on the amplifiers to prevent their damage. It sounded just like a room full of mousetraps gone crazy.

I did help them quite a bit when they needed a source of white noise to test a simulated missile guidance system for its response to noise as the missile approached its target. I set up a bank of NE-2 neon bulbs as relaxation oscillators. Some were fed from a positive voltage and the rest from a negative voltage.

The firing times were random, determined by the R-C networks’ charging times. The discharge currents fed into a common small resistor for all of them, and the signal across this resistor was the noise signal fed to the amplifiers.

On a more serious note, back at my regular job there, I did obtain U.S. patent #3,899,244, along with Bill Porter for a “Frequency Diversity Radar System” or anti-jamming radar. It was classified Secret for years after issue, and even I couldn’t have a copy until it was declassified.

Years after that I learned in the magazine American Heritage of Invention and Technology that Heddy Lamarr (the actress) had also obtained an earlier patent for a frequency diversity radio system for submarine torpedo guidance!

J. DAVID PFEIFFER

HELLO, JOHN,

That’s an old story, now well known. Thanks for writing. And to hell with McAfee!           RAP

Comments invited! czar44@me.com —or:
R.A. Pease, 682 Miramar Avenue
San Francisco, CA 94112-1232