Building a paper tape reader is no walk in the park, but it's not rocket science either. The fundamental components include a reliable light source, photoreceptors positioned behind the tape to detect holes, and a mechanism to pull the tape through the reader efficiently. The real challenge lies in achieving that last piece, as David Lovett from Usagi Electric can attest, having navigated the complexities of retrofitting his DIY vacuum tube-era reader.

One critical aspect of this project is the paper tape's feed rate, which is directly linked to the computer's reading speed. In Lovett's design, this paper tape serves as the Read-Only Memory (ROM) for the custom UE1 computer, which means that all data must be executed on-the-fly since the system lacks Random Access Memory (RAM) for instruction storage. Lovett ingeniously designed the system to run the tape in an endless loop, enabling the computer to 'jump' between different code sections much like a programmer jumps to functions in software coding. This is accomplished by masking off segments of code until the desired address is reached, making it a fascinating dance of mechanics and programming.

To bring this ambitious project to life, Lovett opted for a slot car motor paired with a speed-reduction gear, ingeniously designed in FreeCAD. With help from his brother’s hobby machine shop and expertise from a CAD professional, constructing the necessary parts was a breeze. The final assembly included guides for the tape, much like those found in cassette players, ensuring smooth maneuvering of the tape throughout the reading process.

The next crucial step involves wiring the photodiodes. Once this is complete, Lovett believes the UE1 could come to life, running programs directly off the paper tape. This creative blend of vintage technology and innovative engineering highlights a remarkable resurgence of interest in vacuum tube computing. Stay tuned, because once this thing roars into action, it promises to be a captivating blast from the past!

Is this the revival of a long-lost era in computer history? Don’t miss the upcoming updates!