It seems like a sweet project is coming together right around the time when I'm ready for more work. Banking info and numbers have been traded so that seems positive. If money lands then I'll be able to talk (and release WIP videos) about it.

Can you guess my new project by this part? (dimensions are close but not yet exactly correct)

Hint #3: The base part shown is an inner frame and is around 43cm (17") wide.

Hint #4: At the end of the project there will be six of them and they'll be in a museum exhibit.

Hint #8: These are metal frames to which rather beige case parts will be attached. The blue is where the glass would be.

Ok, I now have permission to talk about this project in full and in public. I'm working with Alan Kay to build six replicas* of a Xerox PARC Alto display for use in a museum exhibit**. Visitors will see a real Alto and then walk over to one of the replicas to futz with Smalltalk '78***.
Here's a nice writeup of a different project that rejuvenated an actual Alto.

* by "replicas" I mean that they'll look and feel as close to the original as possible but inside will be modern technology. I'm not replicating the original CRTs and driver electronics.
** the museum is in the UK (where Kay now lives) but I'll leave it to them to make their own announcement.
*** this version of Smalltalk was thought lost but then was saved by a dumpster diver who found Alto drive cartridges in the trash!

My general plan is to laser cut and bend inner frames for the portrait oriented displays and the uniquely U-shaped bases, then hang the case elements (with their many complex curves) and electronics on those frames. I've ordered a large format additive printer to avoid seams and joints where they don't belong and while that's in transit I'll be running materials tests and furthering the CAD drawings. I have reference photos of Kay's personal Alto so that I can nail the dimensions.

If this seems to you a bit out of the blue then you're a bit correct, but I have a history of reproducing real and theoretical intellectual infrastructure (e.g. my two Memex builds) and I used to work as a prototype engineer in the PARC lab where the Altos (and laser printing, and Ethernet) originated. That all happened well before I worked there, but that's how I'm connected to that community.

Now that I have permission to share this work I'll start posting WIP photos, videos, and snippets of the design, build, and installation of the replicas. I'm hecking excited to share!

In the meantime, if you're into the Alto then definitely swing by this link to see a metric boatload of photos and document scans like this one from the hardware manual.

While looking into texturing techniques to replicate the original cast parts of the Alto displays I ran across this video about wall texturing and painting techniques. Now I may never be satisfied with flat, boring walls.

I have a few rollers ordered but if those don't work out then I might need to print TPU rollers or CNC cut foam blocks for a custom texture. The last time I tried to replicate a surface texture was before I had additive printers or CNC cutters so this is a new kind of fun for me.

It's fun looking for less than a dozen steel hemispheres because their listed uses are so random. It's a handrail topper. No, it's a chocolate mold. No, it's a salad bowl. No, it's a fire pit!

So far I'm pretty happy with OSH Cut. Their instant quote system is pretty good at telling me how to tweak my designs to get the best cut and bend. The one hiccup I had was quickly and effectively responded to by a support person, Emily. I ordered a couple of samples to see the quality of their cuts and finishes and they look good, so my next step is to polish the design a bit and then order parts for a prototype!

The display swivel mechanism design is coming together. It's basically a cylinder and a hemisphere that squeeze a hemisphere that's welded to the display's base.

Here's one a reference photo of Kay's Alto that shows the display resting on the base's hemisphere. He told me that in retrospect they didn't need a free swivel like that because they only ever tilted the display up and down like nodding your head. It could have been a single-axis.

There's also a sliding potentiometer peeking out from the bottom of the display. I can only assume that it allows the user to change the intensity of their 70s vibe.

A Creality CR-10 S5 is coming my way so I need to rearrange my shop to make room. It has a print volume of 500mm x 500mm x 500mm so it'll handle Alto case parts without adding unnecessary seams. 😸

I plan on reselling it after the Alto replicas ship and I've printed helmets and busts for a few friends. I try not to keep any of my work (except my custom tools) and I generally make smol mechatronics so this big printer isn't a good use of space in my decifactory.

I sort of like the inebriated look of this sweep before I add parametric constraints. In the future it might be fun to make a desktop display with this sort of semi-organic and irregular shape.

There are roughly eleven bazillion shades of old computer beige. I want these replicas to look like they are old new stock that we recently found buried in PARC storage.

This morning's task: Model the case that will slip over the metal frame of the base. The metal frame will be laser cut and bent so I had to design in some material on the front arms that will be ground away to fit inside the case.

Here are the labels attached to the back panel of the Alto model II display that I'm using as reference. It was manufactured for PARC in St. Paul, Minnesota by Ball Electronic Display Division in 1979.

TIL about the Alto "nose boot" in which eleven keys needed to be simultaneously pressed in order to set specific bits during boot of an early build of the OS.

It's not in scope for this project but once I've delivered the Alto display replicas I'll be tempted to replicate the custom Honeywell keyboard that slips into the front cutout of the base. Along with the chording keys and mouse, it would complete the user-facing aspects of the Alto. The Dorado CPU could also drive an Alto display when necessary.


I drew up the bezel in which is the last major external element of the Alto. There are still a number of internal features like fasteners and the LCD fixture as well as a few tweaks to the curves to more closely match the curvaceous cases.

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