Gregory's ServerA simple repair at https://twitter.com/ComputerHistory. The IBM 729 tape drive provided bulk storage on a 2400 ft reel of magnetic tape. But one of the lights on the control panel burned out. It uses an obscure 55-volt telco bulb in an unusual package.
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@supernov The stacks are the pushbutton switches that you can see under the lights in the other photo.  @kenshirriff 😲 I used to have a big box of globes like that! But I don't think any of them were 55V.  @kenshirriff OMG! 729 tape drives! We had 4 of them on our DEC-10 at U Illinois Physics when I was there. I'm amazed that they're still around 50 years later 😮 @kenshirriff I loaded tapes on something like this, back in the 80s. It was fun watching them thread the tape across to the other reel by themselves, and watching the two loops in the vertical channels when it was spinning madly... @kenshirriff I remember these lamps from my childhood, but don't remember the device. Certainly no computer or telephone. |
We have about 50 different bulb types in the workshop but not this kind. Fortunately, I found the bulb online and ordered new ones. Replacing the bulb was quick: swing open the panel, pull out the old bulb, and push the new one in. Now the "select" light illluminates properly.