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A Better Incandescent Look

A project log for DEC H-500 Computer Lab Reproduction

Reproduce the Digital Computer Lab H-500, a training tool from the late 60's aimed at teaching people the basics of logic circuits.

Michael GardiMichael Gardi 07/01/2020 at 04:340 Comments

BrightBlueJim pointed out in a comment to Dan Maloney's blog entry (https://hackaday.com/2020/06/28/reproduction-1960s-computer-trainer-really-pushes-our-buttons/#comments) that the lamps looked blue, which as he pointed out is not very incandescent like (the original used incandescents).  The LEDs are actually white shining through translucent PLA diffusers, but they do look a little blue in the videos. 

So I tried printing the diffusers in both yellow and in the same brown that I used for the rocker switches. 

Hard to see in the picture but the yellow (left) doesn’t look too bad (better than the transparent IMHO), but the brown looked great after I changed the limiting resistor to about 330R to brighten up the LED.  If I were doing it again I would definitely go with the brown diffuser.

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