Symbolics Space Cadet Fails Daily Typing Test Under Heavy Springs

Chyrosran22

The legendary MIT Lisp workstation keyboard functions strictly as a historical showpiece because its stiff 70-gram Honeywell Hall effect switches make everyday typing impractical.

AI-assisted summary of Symbolics Space Cadet keyboard review (Honeywell Hall effect 4B3E) — original source. Check the original for full context.

Source published: 2017-12-23

Key ideas

The Symbolics Space Cadet keyboard, originally bundled with the LM-2 Lisp workstation costing roughly $200,000 in modern purchasing power, is regarded as the ultimate vintage keyboard holy grail with only around 100 systems produced. (1:58)
Featuring seven distinct modifier keys—including introducing Super and Hyper to computing—the keyboard allowed users to chord over 8,000 distinct characters, directly influencing Emacs keybindings. (4:33)
The keyboard employs Micro Switch Honeywell SD series 4B3E linear Hall effect switches rated for 30 billion keypresses, requiring roughly 70 grams of actuation force and bottoming out around 100 grams. (7:45)
Constructed with massive double-shot ABS keycaps weighing up to 2.67 grams per 1U key, the keycaps and switches alone total around 700 grams across a 100-key layout. (11:51)

Detailed notes

## Background Published on YouTube by Thomas (Chyrosran22) on December 23, 2017, this video serves as a year-end review of the iconic Symbolics Space Cadet keyboard. According to the show notes, Thomas examines the keyboard and its Honeywell Hall effect switches as the vintage community's 'holy of holies,' concluding with a typing demonstration and reflections on the past year.

## TL;DR Thomas reviews an exceptionally rare new old stock (NOS) module of the Symbolics Space Cadet keyboard, originally bundled with the roughly $200,000 LM-2 Lisp workstation. He details its historical roots in the MIT AI Lab, its seven modifier keys enabling over 8,000 characters and influencing Emacs key-chording, and its uniquely heavy doubleshot ABS keycaps. After evaluating the contactless Micro Switch Honeywell SD-series Hall effect switches—noting their 30-billion-keypress durability alongside their heavy 70g actuation force and sensitivity to dirt—he concludes that while it is an impractical daily driver, it stands as an unmatched historical collector's showpiece.

## Atmosphere & style The presentation is scholarly yet wonderfully eccentric, blending deep hardware archaeology with Thomas's signature dry wit, sharp candor, and colorful turns of phrase. It feels like an intimate, festive celebration for keyboard enthusiasts, balancing genuine awe over pristine vintage engineering with blunt assessments of the switch weighting. Beneath the technical deep dive lies an affectionate, reflective emotional arc, as Thomas shares his sincere gratitude to his audience for encouraging him to continue producing content into 2018.

## Bulletin - [01:58](https://www.youtube.com/watch?v=oDozftThFMw&t=118s) The Symbolics Space Cadet keyboard, originally bundled with the LM-2 Lisp workstation costing roughly $200,000 in modern purchasing power, is regarded as the ultimate vintage keyboard holy grail with only around 100 systems produced. - [04:33](https://www.youtube.com/watch?v=oDozftThFMw&t=273s) Featuring seven distinct modifier keys—including introducing Super and Hyper to computing—the keyboard allowed users to chord over 8,000 distinct characters, directly influencing Emacs keybindings. - [07:45](https://www.youtube.com/watch?v=oDozftThFMw&t=465s) The keyboard employs Micro Switch Honeywell SD series 4B3E linear Hall effect switches rated for 30 billion keypresses, requiring roughly 70 grams of actuation force and bottoming out around 100 grams. - [11:51](https://www.youtube.com/watch?v=oDozftThFMw&t=711s) Constructed with massive double-shot ABS keycaps weighing up to 2.67 grams per 1U key, the keycaps and switches alone total around 700 grams across a 100-key layout.

## Key takeaways - [00:06](https://www.youtube.com/watch?v=oDozftThFMw&t=6s) The Symbolics Space Cadet keyboard is widely recognized as the 'holy grail' of mechanical keyboards due to its extreme rarity, build quality, and deep hacker heritage. - [00:06](https://www.youtube.com/watch?v=oDozftThFMw&t=6s) The review specimen is a pristine 'new old stock' (NOS) drop-in replacement module, preserving the original vibrant gray and blue keycaps without the sun yellowing common to surviving units. - [01:58](https://www.youtube.com/watch?v=oDozftThFMw&t=118s) The keyboard descends from John McCarthy's 1958 invention of Lisp and Tom Knight's earlier Knight keyboard designed for the MIT AI Lab's CONS and CADR Lisp machines. - [01:58](https://www.youtube.com/watch?v=oDozftThFMw&t=118s) Symbolics was established in 1979 to commercialize CADR technology via the LM-2 workstation, producing only about 100 units at an inflation-adjusted cost of roughly $200,000 each. - [01:58](https://www.youtube.com/watch?v=oDozftThFMw&t=118s) Successor Symbolics 3600 workstations used a downscaled layout with fewer modifiers and eventually transitioned to NMB Space Invader switches with rare doubleshot keycaps. - [04:33](https://www.youtube.com/watch?v=oDozftThFMw&t=273s) The Space Cadet layout features seven modifiers (Shift, Top, Front/Greek, Control, Meta, Super, and Hyper), introducing Super and Hyper keys to computing. - [04:33](https://www.youtube.com/watch?v=oDozftThFMw&t=273s) Multi-tier legends on the keycap tops and front faces let users input over 8,000 characters, including the complete native APL mathematical notation set. - [04:33](https://www.youtube.com/watch?v=oDozftThFMw&t=273s) Aligning modifiers in a tight horizontal line facilitated complex single-handed chording, directly inspiring Emacs shortcut ergonomics. - [04:33](https://www.youtube.com/watch?v=oDozftThFMw&t=273s) The layout integrates unusual terminal keys such as Roman numerals I–IV for list buffers, hand-shaped arrow keys, and a dedicated 'Rub Out' key. - [07:45](https://www.youtube.com/watch?v=oDozftThFMw&t=465s) The board uses Honeywell Micro Switch SD series linear Hall effect switches (primarily model 4B3E) manufactured in Freeport, Illinois, with inspection stickers dating to 1982. - [07:45](https://www.youtube.com/watch?v=oDozftThFMw&t=465s) Contactless Hall effect operation uses a moving magnet over a semiconductor sensor to divert electron flow, yielding a lifespan rating of 30 billion actuations per switch. - [07:45](https://www.youtube.com/watch?v=oDozftThFMw&t=465s) Despite contactless electronics, Honeywell Hall effect switches are acutely sensitive to dust and grit around the sliders, which causes scratchiness and off-axis binding. - [10:25](https://www.youtube.com/watch?v=oDozftThFMw&t=625s) Operating force is heavy at approximately 70 grams actuation and 100 grams bottom-out, making switches like green Alps or Fujitsu leaf springs preferable for actual typing comfort. - [10:25](https://www.youtube.com/watch?v=oDozftThFMw&t=625s) The massive switch assemblies and thick ABS keycaps produce an exceptionally loud, deep, and resonant clatter even without an outer case. - [11:51](https://www.youtube.com/watch?v=oDozftThFMw&t=711s) The ultra-thick Honeywell double-shot ABS keycaps weigh 2.67 grams per 1U key, making them some of the heaviest, most crack-resistant caps ever manufactured. - [11:51](https://www.youtube.com/watch?v=oDozftThFMw&t=711s) Wider keys utilize unpopulated dummy switch housings topped with red 'Christmas bonnet' caps or asymmetric stem mounting for stabilization. - [13:20](https://www.youtube.com/watch?v=oDozftThFMw&t=800s) While too stiff and specialized for practical everyday typing, the Space Cadet stands as an unmatched historical centerpiece and collector's item.

## Detailed walkthrough ### [00:06](https://www.youtube.com/watch?v=oDozftThFMw&t=6s) The Holy Grail of Vintage Keyboards

To close out the year, Thomas reviews what is widely considered the "holy grail" of mechanical keyboards: the Symbolics Space Cadet keyboard. Deeply rooted in hacker culture, the Space Cadet is excessively rare, enormously expensive, extraordinarily well-made, and insanely complex. As Thomas jokes, “forget the Happy Hacking Keyboard, real hackers used this.” The review unit was loaned to him by an administrator from Deskthority, which Thomas describes as one of the three major hubs of the Western mechanical keyboard community and the one most dedicated to vintage hardware.

```mermaid flowchart TD accTitle: Space Cadet Lineage and Context accDescr: Chronology of the Space Cadet keyboard within MIT Lisp development and workstation hardware.

subgraph MIT["MIT AI Lab Origins"] A["1958: John McCarthy invents Lisp"] --> B["1973: Knight & Greenblatt start Lisp Machine Project"] B --> C["Knight Keyboard designed by Tom Knight"] end

subgraph Symbolics["Commercialization"] C --> D["1979: Symbolics founded<br/>Space Cadet on LM-2 workstation"] D --> E["Symbolics 3600 Series Keyboard"] E --> F["NMB Space Invader revisions<br/>(Doubleshot keycaps)"] end ```

The particular board shown lacks an outer enclosure. While production Space Cadets shipped in an understated white case bearing the Symbolics badge, this unit is a drop-in replacement module preserved as new old stock (NOS). This pristine state proves critical for its appearance. While the well-known Wikipedia photo displays a severely sun-damaged specimen with faded blues and gray keys that turned brown, this NOS unit has perfectly preserved, vivid gray and blue plastic. Thomas challenges the misconception that people in the 1980s lived dull beige lives, admiring the original color palette far above most modern custom keycap sets, even while acknowledging that modern Space Cadet-inspired tribute sets are quite cool.

- **Collector status:** Widely acknowledged as the holy grail due to extreme rarity, complexity, cost, and historical ties to MIT hacker folklore. - **Unit condition:** Caseless new old stock (NOS) drop-in replacement module, avoiding the typical yellowing and fading seen on sun-damaged units.

---

[01:58](https://www.youtube.com/watch?v=oDozftThFMw&t=118s) Lisp Machines and the Birth of Symbolics

The technical pedigree of the Space Cadet traces back to 1958, when John McCarthy devised Lisp during his fellowship at MIT in Cambridge, Massachusetts. Centered around lists, recursive functions, and symbolic expressions, Lisp became one of the earliest high-level programming languages and was inextricably linked to artificial intelligence research. By 1973, Tom Knight and Richard Greenblatt at the MIT Artificial Intelligence Laboratory launched the MIT Lisp Machine Project to develop dedicated hardware optimized for running Lisp environments. Their early prototypes, named the CONS and CADR machines, rapidly grew into indispensable tools for MIT hackers.

In 1979, Greenblatt was approached to commercialize the technology for a broader market, resulting in the formation of Symbolics—a name inspired by Lisp’s reliance on symbolic expressions. Symbolics released its first product, the LM-2, which was essentially a rebadged CADR machine and represented the first commercially available computer workstation in the modern sense. The LM-2 came equipped with the Space Cadet keyboard, designed by Tom Knight as an expanded evolution of his earlier "Knight keyboard." Only about 100 LM-2 systems were ever built, each carrying a price tag equivalent to roughly $200,000 in modern purchasing power, explaining why surviving Space Cadet keyboards are practically unobtainable today.

Later, Symbolics replaced the LM-2 with the 3600 series, which was paired with a simplified, downscaled keyboard. That successor unit retained a very similar internal architecture to the Space Cadet but adopted a plainer white-and-gray color scheme and discarded many dedicated modifier keys. Thomas notes that the fact he can casually mention the 3600 series keyboard in passing—despite it being famous, exceptionally rare, and very expensive in its own right—highlights the legendary tier occupied by the Space Cadet. The 3600 keyboard was eventually superseded by three revisions manufactured by NMB, which utilized "Space Invader" switches alongside doubleshot keycaps, a rare feature for NMB that Thomas had not encountered prior to borrowing this keyboard.

- **Key individuals:** John McCarthy (Lisp creator, 1958); Tom Knight and Richard Greenblatt (MIT Lisp Machine project, 1973; Symbolics co-founders). - **Hardware lineage:** MIT CONS/CADR prototypes → Symbolics LM-2 workstation (bundled with the Space Cadet) → Symbolics 3600 series. - **Rarity factor:** Around 100 LM-2 workstations produced, each originally costing what equates to approximately $200,000 today.

---

[04:33](https://www.youtube.com/watch?v=oDozftThFMw&t=273s) Seven Modifiers and Over 8,000 Characters

The primary design goal of the Space Cadet keyboard was enabling the operator to input as vast an array of characters as possible. To accomplish this, Tom Knight implemented seven distinct modifier keys: 1. Shift 2. Top 3. Front (also labeled Greek) 4. Control 5. Meta 6. Super 7. Hyper

The keyboard introduced Super and Hyper to the computing world. Compared to modern desktop layouts that rely merely on Shift, Control, Alt, and the occasional Windows key, the Space Cadet is an extreme specialty instrument.

```mermaid flowchart LR accTitle: Character Layer Access Logic accDescr: How modifier keys layer character outputs on an individual Space Cadet keycap.

subgraph Modifiers["Layer Modifiers"] S["Shift"] T["Top"] G["Front / Greek"] C["Control / Meta / Super / Hyper"] end

subgraph BaseKey["Key 'A' Examples"] direction TB OutBase["Base: 'a'"] OutShift["Shift + A: 'A'"] OutTop["Top + A: '⊥' (Upside-down T)"] OutGreek["Greek + A: 'α' (Lowercase Alpha)"] OutShiftGreek["Shift + Greek + A: 'Α' (Capital Alpha)"] OutBuckey["Chords: Complex symbols / APL"] end

S --> OutShift T --> OutTop G --> OutGreek S & G --> OutShiftGreek C --> OutBuckey ```

Key legends are divided across multiple faces of each keycap. Pressing `Shift` produces standard uppercase letters. Pressing `Top` activates the character printed on the top face of the keycap (for example, typing `Top + A` outputs an upside-down T, $\bot$). Pressing `Front` (Greek) inputs the character shown on the front face (such as `Front + A` producing a lowercase alpha, $\alpha$), while `Shift + Front + A` produces an uppercase Alpha ($A$). Combining these layers with `Control`, `Meta`, `Super`, and `Hyper` allowed users to type over 8,000 distinct characters, including the complete native APL mathematical character set directly printed on the keys.

Thomas jokes that pressing `Control + Meta + Super + Hyper + C` might yield an emoji of a Coca-Cola bottle or a giant black square for all he knows, marveling: “I didn't even know there were 8,000 characters.” Reflecting on its title, he remarks, “now I have no idea why this thing was called the Space Cadet keyboard, but considering the insane complexity of this thing, it makes me think that if you used to use one of these you must be a bit of a fruitcake.” Thomas points out that having earned a PhD in chemistry himself, if those operators were fruitier than him, “that's really saying something.”

The modifiers were placed close together in a straight horizontal line to let users press several keys simultaneously with one hand. This arrangement directly shaped the key-chording design of the Emacs text editor. Still, contemporary operators joked that the keyboard was best suited to someone with three or four hands. Symbolics seemingly agreed in hindsight that the layout was excessive, reducing the character count on the 3600 keyboard down to roughly 2,000. Beyond the modifier cluster, the layout features unusual terminal keys: Roman numerals I through IV for selecting list buffers, cursor navigation keys printed in the shape of small hands, a host of specialized terminal commands, and a `Rub Out` key, which Thomas quips certainly meant something different at the time than it does today.

- **Total input capability:** Over 8,000 characters via modifier chords, including complete native support for APL notation. - **Modifier lineup:** Seven modifiers (Shift, Top, Front/Greek, Control, Meta, Super, Hyper); introduced Super and Hyper. - **Historical impact:** Modifier alignment influenced Emacs keyboard shortcut ergonomics. - **Novelty keys:** Roman numerals I–IV, hand-shaped arrow keys, specialized terminal controls, and a `Rub Out` key.

---

[07:45](https://www.youtube.com/watch?v=oDozftThFMw&t=465s) Micro Switch Hall Effect Switches: Design and Feel

Examining the metal chassis reveals a production date sticker from 1982 alongside manufacturing marks from Micro Switch, a division of Honeywell, located in Freeport, Illinois. Micro Switch outfitted the board with their legendary SD series linear Hall effect switches. While various spring weights and switch variants exist across the assembly, the predominant switch type used is the `4B3E`. This model is rated at 2.5 ounces of operating force, which Thomas's research converts to approximately 70–75 centinewtons (or grams-force).

Hall effect switches operate contactlessly using a permanent magnet and a semiconductor sensor. Depressing the key brings the magnet toward the semiconductor, which diverts the path of passing electrons and generates a transverse voltage proportional to the magnet's proximity. Because there are no physical electrical contacts scraping together, mechanical wear is practically non-existent; the switches are rated for a staggering 30 billion keypresses per switch. The physical slider is mechanically decoupled from the electronic sensing mechanism—it can simply be pulled out—drastically reducing operational friction.

The main weakness of Honeywell Hall effect boards is their acute sensitivity to dirt and particulate contamination: “although they can potentially be very smooth, they actually really don't like dirt much at all, which is ironic for a contactless switch.” While this NOS unit provides a rare opportunity to test the switches in factory-fresh condition, Thomas observes that it is not 100% spotless. A few specific keys have minor grit around the sliders, causing immediate scratchiness and slight off-axis binding. The vast majority of the keys, however, remain immaculate. The key travel is relatively deep at slightly over 4 mm; while the linear actuation feels somewhat monotonous across the stroke, it remains remarkably smooth and pleasing under typing.

- **Manufacturer & date:** Micro Switch (a division of Honeywell), Freeport, Illinois; chassis inspection sticker dated 1982. - **Switch variant:** Honeywell SD series linear Hall effect, predominantly model `4B3E`. - **Weighting:** 2.5 ounces (~70–75 cN / grams-force). - **Lifespan rating:** 30 billion keypresses per key. - **Travel characteristics:** Contactless linear stroke measuring slightly over 4 mm of travel; exceptionally smooth when clean, but prone to binding and grit if dust enters the housing.

[10:25](https://www.youtube.com/watch?v=oDozftThFMw&t=625s) Switch Weighting and Sound Profile

Evaluating the keyboard's overall typing experience, Thomas notes that the switches are surprisingly not the board's strongest attribute. The Honeywell Hall effect switches feature a heavy weighting of roughly 70 grams of actuation force and a bottom-out weight of around 100 grams, matching the stiff profile of the switches found in his ITT Courier keyboard. While Honeywell manufactured lighter variants, and the natural smoothness of the switch mechanism helps soften the impact of the heavy springs, the action remains noticeably stiffer than Thomas prefers. Comparing them against other vintage linear mechanisms, he finds that switches like green Alps and Fujitsu leaf springs deliver comparable smoothness alongside far more agreeable spring weights. Thomas delivers his verdict on the switches' mythic standing: “I think their legendary reputation is a little bit exaggerated, but at the same time this isn't quite the end of the Honeywell Hall effect story yet; there will be more on that topic at a later point in time in the new year.”

Because the switch assemblies are large and densely constructed, and the accompanying keycaps are massive, the keyboard produces an exceptionally deep, resonant sound. Even without an exterior chassis or bottom case installed to act as an acoustic chamber, typing on the bare metal assembly yields a loud, authoritative clatter that fully delivers on expectations.

- Actuation force: approximately 70 grams - Bottom-out force: approximately 100 grams - Preferred vintage linear alternatives cited: green Alps and Fujitsu leaf spring switches

---

[11:51](https://www.youtube.com/watch?v=oDozftThFMw&t=711s) Honeywell Keycaps and Stabilizer Architecture

The keycaps mounted on the Space Cadet are Honeywell's oversized double-shot ABS blocks, ranking as the second-thickest caps Thomas has encountered behind Fujitsu. Unlike Fujitsu's caps, however, the Honeywell design is less prone to cracking or stem breakage, leading Thomas to describe them as arguably the best keycaps ever produced. A standard 1-unit keycap weighs up to 2.67 grams—more than two and a half times the mass of an equivalent Cherry MX lasered PBT cap, and heavier than an entire Cherry MX switch and keycap combined. With individual switch modules weighing over 4 grams, a 100-key layout carries nearly 700 grams in switches and caps alone. In typical colorful fashion, Thomas marvels at the sheer mass: “That's almost one-and-a-half times the weight of a whole Apple aluminium keyboard—Jesus Christ on a meat popsicle.”

The stabilization method varies across the layout. Wider keycaps are supported using unpopulated dummy switch housings topped with an unusual red cap resembling a tiny Christmas bonnet. Keys too narrow for full wire or dummy stabilization rely on asymmetrically placed switch mounts. While off-center keystrokes can cause noticeable binding on grimy or worn Honeywell boards, the pristine condition of this Space Cadet keeps friction to a minimum. Visually, the board is defined by a muted blue-and-gray colorway complemented by elaborate secondary and tertiary programming legends, including mathematical logic symbols such as NOR.

```mermaid flowchart TD accTitle: Space Cadet Stabilization and Mounting Architecture accDescr: Diagram illustrating how different key widths are stabilized on the Honeywell Hall effect assembly.

subgraph WideKeys["Large Stabilized Keys"] A["Wide Keycap"] --> B["Active 4B3E Switch"] A --> C["Dummy Switch Housing"] C --> D["Protective 'Christmas Bonnet' Cap"] end

subgraph MidKeys["Intermediate Keys"] E["Medium Keycap"] --> F["Off-Center Asymmetric Stem Mount"] F --> G{"Cleanliness Factor"} G -->|"Dirty Unit"| H["Off-Center Binding"] G -->|"Pristine Unit"| I["Smooth Travel"] end ```

- Single 1U keycap weight: up to 2.67 grams - Individual switch module weight: over 4 grams - Combined weight of 100 switches and keycaps: approximately 700 grams - Color scheme: classic two-tone grey and blue featuring complex multi-tier legends

---

[13:20](https://www.youtube.com/watch?v=oDozftThFMw&t=800s) Collector Value, Channel Retrospective, and Typing Demonstration

Weighing the Space Cadet's practical utility against its status in the mechanical keyboard community, Thomas emphasizes that the board exists fundamentally as a historic showpiece. While the heavy switches make it impractical as an everyday driver, its imposing physical presence, striking color combination, and rich Lisp machine lineage give it unrivaled collector appeal. In Thomas's assessment: “Now I'll be brutally honest, the only real reason to get one of these is as a showpiece or a collector's item, but what a collector's item this is!”

Closing out the final video of 2017, Thomas reflects on what proved to be the most successful year in the channel's history. He admits that he originally planned to stop publishing videos altogether at the end of the year—and had contemplated not producing content in 2017 at all—but the overwhelmingly positive reception, along with viewer donations and services, convinced him to carry on into 2018. He notes that with an extensive backlog of hardware to showcase and earlier reviews to revisit, stepping away now would be a waste. Following expressions of gratitude to the audience, the review concludes with an extended typing demonstration on the Symbolics Space Cadet using the practice sentence: *“Hello my name is Thomas and I'm typing on a Space Cadet keyboard right now. Thank you all so much for everything, it's been a wonderful year! I'll see you next time in 2018!”*

## Mentioned Symbolics Space Cadet keyboard, Honeywell Hall effect 4B3E, SD series, Micro Switch, Honeywell, Symbolics, Symbolics LM-2, Symbolics 3600 series, MIT Artificial Intelligence Laboratory, CONS, CADR, Knight keyboard, John McCarthy, Tom Knight, Richard Greenblatt, Lisp, APL, Emacs, Deskthority, NMB, Space Invaders switches, Green Alps, Fujitsu leaf spring switches, ITT Courier keyboard, Happy Hacking Keyboard, Cherry MX

## Video description Skip to 14:40 for a typing demonstration. How Hall effect keyboard switches work: https://www.youtube.com/watch?v=37tdDoC7rGA&t=136s

Follow me on Twitter for updates on my keyboard videos! https://twitter.com/chyrosran22

My other keyboard reviews: https://www.youtube.com/playlist?list=PL285ATFsHGY9JnaQemdjRLEMmLRKpmbfB

I'm Thomas and I do keyboard videos and reviews. Today we look at the Symbolics Space Cadet keyboard. What better way to end the year than by reviewing the holyn of holies? :D

The practice sentence was: "Hello my name is Thomas and I'm typing on a Space Cadet keyboard right now. Thank you all so much for everything, it's been a wonderful year! I'll see you next time in 2018!"

[Source](https://www.youtube.com/watch?v=oDozftThFMw)

中文简报

Symbolics Space Cadet因弹簧过重难以胜任日常打字这款传奇的MIT Lisp工作站键盘更适合作为历史展品，其偏硬的70克霍尼韦尔霍尔效应轴体让日常打字变得极不实用。 Thomas评测了一款极其罕见的全新库存（NOS）Symbolics Space Cadet键盘，该键盘最初随价值按现今购买力计算约合20万美元的LM-2 Lisp工作站附带。他详细介绍了其源自MIT人工智能实验室的历史渊源、可输入超8000个字符并深刻影响Emacs组合键设计的七个修饰键，以及其独特的厚重双色注塑ABS键帽。在评估了无触点的微动开关霍尼韦尔SD系列霍尔效应轴体——指出其拥有300亿次敲击寿命，但触发力度高达70克且对灰尘敏感——之后，他得出结论：虽然这款键盘作为日常主力工具并不实用，但作为一件历史收藏品，其地位无可比拟。 Symbolics Space Cadet键盘最初随按当今购买力约合20万美元的LM-2 Lisp工作站附带，由于该系统仅生产了约100套，被视为复古键盘界终极的“圣杯”。 (1:58) 该键盘配备了七个独立的修饰键——包括首次在计算机领域引入Super键和Hyper键——支持用户通过组合键输入8000多种不同字符，直接影响了Emacs的快捷键设定。 (4:33) 该键盘采用微动开关霍尼韦尔SD系列4B3E线性霍尔效应轴体，标称敲击寿命达300亿次，触发力度约为70克，触底力度约为100克。 (7:45) 该键盘采用厚重的双色注塑ABS键帽，每个1U键帽重达2.67克，在100键布局下，仅键帽和轴体的总重就达到约700克。 (11:51)

Original transcript

[0:06] [Music] [0:09] hello and welcome to this review of the [0:12] space-cadet keyboard [0:13] you didn't think I'd finish off the year [0:15] without doing one of these did you [0:17] the space-cadet keyboard is often said [0:20] to be the holy grail of keyboards as [0:22] it's excessively rare very expensive [0:25] very well made insanely complex and it's [0:28] deeply buried and hacker culture so [0:31] there you go forget the happy hacking [0:33] keyboard real hackers used this this one [0:36] is on loan to me by one of the admins of [0:38] desk Authority which is one of the three [0:40] main hubs of the Western mechanical [0:42] keyboard community and of the three it's [0:45] the one most focused on vintage [0:47] keyboards so obviously if I was going to [0:49] find one of these anyway it would be [0:51] there you'll immediately notice that it [0:53] doesn't have a case originally these [0:55] came with a rather plain white case [0:57] bearing Symbolics badge however this is [1:00] a drop-in replacement module and yes [1:02] that means it's new old stock which is [1:05] excellent for several reasons that we'll [1:06] get to later but the first one is in the [1:08] way it looks as you can see from this [1:10] picture which is actually the one on [1:12] Wikipedia the blue and the blue Keys is [1:14] kind of faded and the grey keys have [1:16] gone Brown which means that that one has [1:18] been rather badly sun-damaged [1:20] unfortunately this one being no old [1:23] stock still has two colors very nicely [1:25] preserved and that's a big plus because [1:27] personally I think it's gray and blue [1:29] color scheme looks really nice anyone [1:32] who thinks people in the eighties let [1:34] dole brown or beige lives think again I [1:37] know there are a lot of modern custom [1:39] key cap sets with all kinds of color [1:41] schemes but I don't really like most of [1:43] those these though I mean wow [1:47] and yes I know there are space-cadet [1:49] inspired custom key cap sets which is [1:52] pretty cool actually anyway this [1:54] keyboard has a lot of history obviously [1:56] so let me give you some background info [1:58] in 1958 Lisp a programming language [2:02] centered around lists recursive [2:04] functions and symbolic expressions was [2:06] devised by John McCarthy during his [2:09] fellowship at MIT in Cambridge [2:10] Massachusetts it was one of the first [2:13] Pro graeme languages and it was [2:15] intimately linked to artificial [2:16] intelligence research in 1973 Tom Knight [2:20] and Richard Greenblatt from the AI lab [2:22] at MIT started a project called the MIT [2:25] Lisp machine project to develop [2:27] computers based around the Lisp [2:29] programming architecture at first this [2:32] was a very small-scale operation mostly [2:34] centered around MIT itself and the first [2:37] two versions constant kada quickly [2:40] became standard tools for hackers six [2:42] years later in 1979 Greenberg was [2:46] approached with the idea to [2:47] commercialize the technology and expand [2:49] it to a wider audience this joint [2:51] venture became a company called [2:53] Symbolics presumably named after lisps [2:55] reliance on symbolic expressions and the [2:58] first product the lm-2 which was [3:00] essentially a rebadged Kader machine [3:02] became what was at the time the first [3:04] commercially available workstation as we [3:07] now know it it was this machine that LM [3:09] - that came with a space cadet keyboard [3:12] the space cadet was designed by Tom [3:14] Knight one of the people at the MIT AI [3:17] lab and it was an expanded version of [3:19] his earlier night keyboard used on one [3:21] of their display systems because the [3:24] space cadet ships mostly only with the [3:26] LM - of which there were only about [3:28] hundred units produced each one of which [3:30] Sol that was now equivalent to about 200 [3:33] ground the space-cadet keyboard is [3:35] exceptionally rare and hard to get hold [3:37] of it was succeeded by a much more [3:39] simplified and more plain-looking [3:41] symboliks keyboard which came with a [3:43] 3600 series of machines that replace the [3:46] LM - this keyboard is internally much [3:49] the same as the space cadet but it's [3:50] smaller doesn't have as many buttons and [3:52] it has a white and grey color scheme [3:55] rather than the more lively grey and [3:57] blue palate of the space cadet in many [3:59] ways though the review also covers most [4:02] aspects of the symboliks keyboard the [4:04] fact that I can get away with just [4:06] mentioning this keyboard and passing [4:08] even though it's also very famous very [4:10] rare and very expensive is a good [4:13] indication of what level the space cadet [4:15] is on by the way [4:16] the symbolic ski board itself was later [4:19] replaced by a keyboard at three [4:21] different revisions all of which were [4:23] made by NMB using space invader switches [4:26] and someone uniquely for NMB using [4:29] double Schottky caps which I didn't even [4:31] know existed before I borrowed this one [4:33] the space-cadet keyboard was [4:35] specifically developed to be able to [4:37] type as many characters as possible and [4:39] this is why it included as many as seven [4:41] modifier keys top Greek or front shift [4:45] control meta super and hyper the latter [4:49] two of which it introduced compare that [4:51] to the more common three modifier keys [4:53] ctrl alt shift and nowadays the [4:56] occasional use of a Windows key and you [4:59] can see that the space cadet is really [5:01] quite a specialty keyboard so the shift [5:04] key obviously accessed capital letters [5:06] and such while the top key accessed the [5:09] characters shown at the top of the key [5:10] caps and front the characters at the [5:13] front of the key caps which were mostly [5:15] Greek letters which is why the front cap [5:17] was also labeled Greek so for example if [5:20] I typed shift a I would get an uppercase [5:23] a if I typed top a I would get an [5:26] upside-down T and Greek a I would get a [5:30] lowercase alpha and shift Greek a I [5:33] would get an uppercase Alpha but that's [5:36] just a capital letter a the character [5:38] set was further expanded using the [5:40] control meta super and hyper Keys which [5:43] could be used in various combinations to [5:45] yield even more characters for example [5:48] you could press control metas super [5:51] hyper c2 gets I don't know maybe an [5:54] emoji in the shape of a bottle of coke [5:56] or whatever it could have typed her a [5:58] giant black for all I know all in [6:01] all you could type over 8,000 characters [6:04] on this keyboard using various [6:06] combinations of keys and modifiers [6:08] including the entire APL character set [6:11] which is actually natively shown on the [6:12] key caps I mean I didn't even know there [6:15] were 8,000 characters now I have no idea [6:19] why this thing was called the [6:20] space-cadet keyboard but considering the [6:23] insane complexity of this thing it makes [6:25] me think that if you used to use one of [6:27] these you must be a bit of a fruitcake [6:29] and that's coming from someone with a [6:31] PhD in chemistry so if there are even [6:34] fruitier than me that's really saying [6:36] something the modifiers were [6:38] specifically placed close to each other [6:40] and in a line so that you can easily [6:42] press multiple at the same time and this [6:44] is apparently one of the design [6:46] decisions that influenced the design of [6:47] Emacs which also makes frequent use of [6:49] multiple modifier keys that said some [6:53] users at the time did remark it would be [6:55] more suited to an operator with three or [6:57] four hands in fact even the makers must [7:00] have thought in retrospect that all this [7:02] might have been slightly over the top [7:05] because the symbolic ski board that soon [7:07] replaced it could only type about two [7:10] thousand characters and it was much [7:12] smaller and simpler in design and by [7:15] extension not quite as cool of course [7:17] other funky keys present on the keyboard [7:20] include Roman numerals one through four [7:22] for switching between lists what appears [7:25] to be arrow keys in the shape of little [7:27] hounds which is pretty cute all kinds of [7:29] weird terminal commands and even a rub [7:32] out key which I assume didn't mean back [7:35] then what it does now I'll admit all [7:38] this funky stuff does give the [7:39] space-cadet keyboard a very unique [7:41] character though I just love crazy [7:43] like this if we have a look at this [7:46] chassis itself we can find a date [7:47] sticker from 1982 which makes sense and [7:50] a sticker showing that it was made in [7:52] Freeport Illinois in the USA by micro [7:55] switch a division of Honeywell and yes [7:58] that points directly towards the [8:00] switches which are honeywell's rather [8:01] famous SD series of linear Hall effect [8:04] switches they came in various weightings [8:07] and types including on this board but [8:09] most of the switches are type 4 B 3 E [8:13] which is weighted at 2.5 alders which [8:17] are looked up and it's equivalent to 74 [8:20] milliliters of force somehow these [8:24] switch is a base of magnets and they [8:26] make use of the whole effects to bend [8:28] electrons off a path through a [8:29] semiconductor to create a voltage [8:31] transverse to the main current which is [8:33] non linearly dependent on the proximity [8:35] of the magnet I've discussed in great [8:38] detail how this works in my ITT career [8:40] video so if you want a more in-depth [8:42] explanation of how this works click the [8:45] link in the description below to take [8:47] you directly to it in short it's based [8:49] on a transverse voltage stemming from [8:51] electromagnetic dial version of [8:53] electrons through a semiconductor but if [8:55] you want to know how it works in detail [8:57] watch the video the result of this [8:59] design is a contactless switch that has [9:01] the potential to be excessively reliable [9:03] as well as smooth the first is because [9:06] magnets obviously pretty damn hard to [9:08] wear out so these switches are rated at [9:10] 30 billion keypresses put a key which is [9:14] completely insane and the smoothness [9:16] comes from the lack of contact necessary [9:19] between the slider and the contact [9:20] mechanism which in fact is completely [9:23] separate you can just pull it out and [9:25] less contact means less friction which [9:28] means is smooth the switch now one thing [9:30] I've noticed with these Honeywell [9:31] hall-effect balls is that although they [9:33] can potentially be very smooth they [9:35] actually really don't like dirt much at [9:37] all which is ironic for a contactless [9:39] switch but still really you need to get [9:42] these in pretty clean condition to get [9:43] the most out of them and thankfully [9:45] that's why this one being new old stock [9:47] is such a perfect occasion to judge the [9:49] key feel at that best and most [9:51] definitely it's quite interesting at [9:53] that now it's not actually 100% clean in [9:57] fact a few the keys have a little bit of [9:59] grit around them and this is instantly [10:01] noticeable in the key feel [10:06] which is grittier and which binds a [10:09] little bit compared to other keys in the [10:11] keyboard the rest of the keys are in [10:13] excellent condition though and they feel [10:15] very smooth the travel is a bit deep [10:18] slightly over four millimeters and it's [10:21] somewhat monotonous in a way but it's [10:22] definitely pretty nice and smooth that [10:25] said I would say that the switches are [10:27] actually not the board's strongest point [10:29] the weighting is pretty stiff at around [10:31] 70 grams of actuation force and a bottom [10:34] hat weight of around a hundred grams [10:36] which was the same weighting as the ones [10:38] in my ITT Courier keyboard which were [10:40] also too stiff for me they did do [10:43] versions of these with lighter [10:44] weightings such as this one and the [10:47] smoothness actually takes the edge off [10:49] of the worst of the stiffness in this [10:51] keyboard but it's still more than I [10:53] would have liked I'll be honest although [10:55] these switches are really good and [10:57] definitely unmatched in terms of [10:59] reliability there are linear switches [11:01] I'd prefer over these especially green [11:04] Alps and Fujitsu leaf springs were both [11:07] very smooth as well and perfectly [11:10] weighted to boot I think their legendary [11:13] reputation is a little bit exaggerated [11:15] but at the same time this isn't quite [11:17] the end of the honey wall Hall effects [11:19] story yet there will be more on that [11:21] topic at a later point in time in the [11:23] new year the switches are rather large [11:25] and densely made and the key caps a [11:27] humongous so obviously you'd expect a [11:30] pretty full typing sound wouldn't you so [11:32] let's see [11:38] [Applause] [11:43] yeah I think that fits the bill pretty [11:46] well wouldn't you say not bad for a [11:48] keyboard that doesn't even have a case [11:49] around it and speaking of the key caps [11:52] there Honeywell's famous giant blocks of [11:54] double shot abs they're the 2nd thickest [11:57] caps I know of behind Fujitsu but [12:00] personally I think they're actually [12:01] slightly better made because they're [12:03] less prone to breakage in fact [12:05] Honeywell's key caps are arguably the [12:07] best caps ever made ever the single unit [12:11] ones weigh up to two point six seven [12:13] grams each which is over two and a half [12:16] times the weight of an equivalent cherry [12:18] MX lasered PBT key cap in fact they [12:22] weigh more apiece than an MX cap found [12:24] the switch put together and considering [12:27] the switches are over four grams [12:29] themselves as well a keyboard with 100 [12:32] of these would have almost 700 grams [12:34] just in key caps and switches on it [12:38] that's almost one-and-a-half times the [12:40] weight of a whole Apple aluminium [12:42] keyboard Jesus Christ on a meat popsicle [12:45] the lion Tiki caps are mounted with the [12:48] dummy switch bizarrely wearing a little [12:50] Christmas bonnet on its head and the [12:52] ones too small to stabilize are [12:54] asymmetrically mounted which can lead to [12:57] binding on off-center keypresses [12:59] although it's not too bad on this one [13:01] thanks to the condition it's in an [13:03] Honeywell keyboards that weren't as [13:05] clean I found the binding to be pretty [13:07] bad though and of course the caps have [13:09] that lovely grey and blue color scheme [13:11] that's stylish but not too in-your-face [13:13] and classic without being overbearing [13:15] and they have cool secondary and [13:18] tertiary legends [13:20] NORs now I'll be brutally honest the [13:23] only real reason to get one of these is [13:26] as a showpiece or a collector's item but [13:28] what's a collector's item this is it's [13:31] cool enough to just see it in a picture [13:33] but especially in the flesh it just has [13:35] a lot of presence not to mention a cool [13:37] backstory on a slightly different note [13:40] 2017 has been by far the biggest year [13:43] for this channel and I thought it only [13:44] fitting to review the Holy of Holies as [13:47] the last video next week there will be [13:49] no video due to the holidays originally [13:52] at the beginning of the year I was going [13:54] to end it on this video and then stop [13:56] doing videos altogether hell I wasn't [13:58] even going to do this year at all but [14:00] the response has been so positive that [14:02] I've decided to keep going on at least [14:04] for the moment I've got so much more [14:05] cool stuff to show you guys let alone [14:08] all videos that I want to revisit [14:09] properly that a thing get to be a [14:11] criminal waste to stop now so the show [14:14] will continue for the while until I [14:16] finally get tired of it you guys get [14:18] tired of it or until I run out of things [14:20] to show you that's it thank you all so [14:23] much for everything your enthusiasm the [14:26] many donations and services many of you [14:28] have provided and of course thanks for [14:30] watching I hope you enjoyed it all and [14:32] following is a typing demonstration of [14:35] me typing on the holy grail of keyboards [14:37] the symbolics space cadet [14:51] [Applause]