Category Archives: display

A Daylight-Readable Bar Graph Display in the 70s Wasn’t Cheap

LEDs weren’t always an easy solution to displays and indicators. The fine folks at [Industrial Alchemy] shared pictures of a device that shows what kind of effort and cost went into making a high brightness bar graph display in the 70s, back when LEDs were both expensive and not particularly bright. There are no strange materials or methods involved in making the display daylight-readable, but it’s a peek at how solving problems we take for granted today sometimes took a lot of expense and effort.

The display is a row of 28 small incandescent bulbs, mounted in a PCB and …read more

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Posted in 70s, bar graph, comparator, daylight readable, display, hardware, incandescent, led, machined aluminum, minitron, retro, retrocomputing, wamco | Leave a comment

Faded Beauty DMM Gets An OLED Makeover

When a fine piece of lab instrumentation crosses your bench, you’ve got to do your best to put it to work. But even in the highest quality devices no component lasts forever, especially vacuum tubes. For some vintage instruments with vacuum fluorescent displays, that means putting up with less-than-perfect digits in order to get that sweet, sweet precision. Or not – you can always reverse engineer the thing and add a spanking new OLED display.

The Hewlett-Packard 34401A digital multimeter that fell into [qu1ck]’s lap was a beauty, but it had clearly seen better days. The display was full of …read more

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Posted in digital multimeter, display, dmm, H-P, hewlett packard, oled, segment, spi, tool hacks, vfd | Leave a comment