Ken Shirriff created a USB interface for a replica of the iconic "keyset" used in Douglas Engelbart's 1968 "Mother of All Demos." This keyset, originally designed for chordal input, now sends USB keystrokes corresponding to the original chord combinations. Shirriff's project involved reverse-engineering the keyset's wiring, designing a custom circuit board to read the key combinations, and programming an ATmega32U4 microcontroller to translate the chords into USB HID keyboard signals. This allows the replica keyset, originally built by Bill Degnan, to be used with modern computers, preserving a piece of computing history.
This blog post by Ken Shirriff details the construction of a custom USB interface for a rare and historically significant keyboard: the keyset used in Douglas Engelbart's "Mother of All Demos" in 1968. This demonstration, a landmark event in computing history, introduced groundbreaking concepts like the mouse, hypertext, and video conferencing to the world. Shirriff's project aimed to make the keyboard, which was originally part of a custom-built input system, usable with modern computers.
The original keyset, which Shirriff acquired, consisted of five keys arranged in a chord keyboard layout. These keys, designed for one-handed operation, could be pressed individually or in combination to produce different characters. The keyset itself lacked any integrated electronics; it simply contained switches that closed circuits when pressed. Its original implementation relied on custom hardware and software tied to the Stanford Research Institute's oN-Line System (NLS).
Shirriff's approach involved designing a circuit board that interfaces the keyset's mechanical switches with a modern computer via USB. He meticulously documented his process, starting with an examination of the keyset's internal wiring and switch mechanisms. This included close-up photographs and diagrams illustrating the physical construction of the keyset. He then proceeded to explain the design and implementation of the USB interface, highlighting his choice of a microcontroller and detailing the necessary firmware to translate key presses into USB HID (Human Interface Device) signals. The firmware utilizes a lookup table to map chord combinations to specific keycodes, effectively emulating a standard keyboard.
The post delves into the technical challenges encountered, such as debouncing the mechanical switches to prevent spurious signals and ensuring reliable communication over USB. Shirriff also discusses the software considerations, including configuring the microcontroller and writing the code to handle key press combinations. The entire project is presented as a fascinating blend of historical preservation and modern electronics, bringing a piece of computing history into the 21st century while preserving its unique functionality. The final product allows the historic keyset to function as a usable keyboard with any modern computer, effectively bridging a 57-year technological gap. The post concludes with reflections on the project and potential future enhancements, like adding a physical enclosure for the electronics.
Summary of Comments ( 78 )
https://news.ycombinator.com/item?id=43453582
Commenters on Hacker News largely expressed fascination with the project, connecting it to a shared nostalgia for early computing and the "Mother of All Demos." Several praised the creator's dedication and the ingenuity of using a Teensy microcontroller to emulate the historical keyset. Some discussed the technical aspects, including the challenges of replicating the original chord keyboard's behavior and the choice of using a USB interface. A few commenters reminisced about their own experiences with similar historical hardware, highlighting the significance of preserving and interacting with these pieces of computing history. There was also some discussion about the possibility of using this interface with modern emulators or virtual machines.
The Hacker News post titled "A USB Interface to the 'Mother of All Demos' Keyset" sparked a discussion with several interesting comments.
One commenter pointed out the historical significance, noting how Engelbart's demo predicted so much of modern computing. They expressed a sense of awe at how Engelbart essentially built the future, emphasizing the monumental nature of his achievements. Another commenter chimed in with a similar sentiment, drawing a parallel to Van Bush's "As We May Think" article, highlighting how these visionaries laid the groundwork for the interconnected digital world we inhabit today.
The technical details of the USB interface also drew attention. One user asked about the specifics of how the chord keyset was implemented, leading to a response explaining the use of a Teensy microcontroller and the QMK keyboard firmware. This exchange offered a glimpse into the practical aspects of the project and the tools used to bring this piece of computing history into the modern age.
Several commenters expressed excitement about the project, with one even stating a desire to build their own. This enthusiasm underscored the enduring appeal of Engelbart's work and the inspiration it continues to provide. Another commenter reflected on the challenges of using such a keyset, acknowledging the steep learning curve but also the potential rewards of mastering a powerful and efficient input method.
There was also a discussion about the original keyset's limitations. One commenter mentioned the difficulty of using it without looking, and another pointed out that the five-finger design was ultimately too complex for widespread adoption. This thread highlighted the balance between innovative design and practical usability.
Finally, a commenter shared a link to Ken Shirriff's blog post about Engelbart's system, offering further context and technical details for those interested in delving deeper into the subject. This provided a valuable resource for anyone wanting to learn more about the historical and technical background of the "Mother of All Demos."
In summary, the comments on Hacker News reflected a mix of admiration for Engelbart's legacy, curiosity about the technical implementation of the USB interface, and discussion about the practicalities and limitations of the original keyset design. The overall tone was one of appreciation for this project that bridges the gap between a landmark moment in computing history and the present day.