The Simple VMW Meter

I have always been fascinated by hooking LEDs up to the parallel port.

Back in 1996 or so I constructed a simple LED meter based on plans you could find at metalab. Basically, you just wire the 8 data lines from the parallel port into LEDs (through a resistor). I also wired up four of the control lines, but have never really used them for anything useful.

Unfortunately across a few moves and some hardware upgrades I lost the original source code. Below is the attempt to recreate it; the timing isn't quite the same as the original but it works well enough and I use it on my desktop at work.

ledmeter-1.0.tar.gz (4k): Ledmeter over parallel port for Linux

Here is a very blurry shot [I should take a better picture] of this meter. The LEDs are from an old mainframe board I bought at a hamfest over a decade ago. The meter itself has been going strong for over 10 years... You can't tell, but it's doing a Knight-Rider type progression: the faster the movement the more CPU being used.

I have been working on a fancier meter off and on for years, see the status of that here.

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