Trevor Flowers rebuilds: Memex and Alto

Earlier:
Memex #001 by Trevor Flowers

My daughter and I built the first working Memex. The outside of the desk sized machine looks and acts like it was built in 1945, the year that Vannevar Bush wrote “As We May Think”.

Memex front view

Subsequently:
https://mastodon.sdf.org/system/cache/media_attachments/files/108/637/796/747/904/197/original/74df7a4463ef7831.png

This week I’m finishing Tiny Memex #5,a 1:6 scale Memex with an SBC inside that drives the displays and accepts input from the lever and buttons.

But announced today a project for a UK museum:

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(1) of a Xerox PARC Alto display for use in a museum exhibit(2). Visitors will see a real Alto and then walk over to one of the replicas to futz with Smalltalk '78(3).

(1) 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.
(2) the museum is in the UK (where Kay now lives) but I’ll leave it to them to make their own announcement.
(3) this version of Smalltalk was thought lost but then was saved by a dumpster diver who found Alto drive cartridges in the trash!

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.
Index of /pdf/xerox/alto

An illustration of the side of an Alto display. It shows various components and fasteners.

And as a bonus:

Here’s a nice writeup of a different project that rejuvenated an actual Alto.

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Here’s a video of the Memex #001 replica in action:

Edit: I’m curious about the photographic process.
(Apparently, this involves flooding the chamber with some gas and an exposure mechanism. In the original, this would have been a dry film process – and the resulting scan looks much like this.)

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In Bush’s original article (well worth reading!), he sketches a process:

Will there be dry photography? It is already here in two forms. When Brady made his Civil War pictures, the plate had to be wet at the time of exposure. Now it has to be wet during development instead. In the future perhaps it need not be wetted at all. There have long been films impregnated with diazo dyes which form a picture without development, so that it is already there as soon as the camera has been operated. An exposure to ammonia gas destroys the unexposed dye, and the picture can then be taken out into the light and examined. The process is now slow, but someone may speed it up, and it has no grain difficulties such as now keep photographic researchers busy. Often it would be advantageous to be able to snap the camera and to look at the picture immediately.

I just realized it is missing one item. Photographs and other paper docs like postcard.
Some sort of scanner is needed,to go to micro film or direct printing…
Ben.

Oh, hey!

I just joined this forum and my search for “Alto” turned up a topic about my work. :smile_cat:

As a bit of a follow-up, I filled a minivan with six of the Alto display replicas and headed to the Computer History Museum in April for their 50th Anniversary of the Alto celebration. Two of the replicas stayed at the CHM so that visitors can play networked Maze War.


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How much did the rebuilds cost, compared to the orginal price?
Ben.

Wonderful! Good to see you here, welcome!

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It depends on how you calculate it. Dr. Kay mentioned that the development of the original Alto cost only around ten million dollars which isn’t a lot compared to modern device development costs.

I wasn’t paid ten million for the six museum replicas, of course. :smile_cat:

I used laser cut steel and aluminum for the inner frames, 3D printed parts (instead of fiberglass) for the cases, and inside the volume where the CRT used to be is a modern small PC driving an LCD. Nobody makes CRTs (especially weird ratio CRTs like the Altos used) so they weren’t an option.

So, material and parts in the replicas probably cost significantly less than the material and parts of the originals. However, each replica takes more than a week of manual work so I’m guessing that the overall cost might be close to or a bit more than Xerox charged for the originals. They had factories to make theirs. I’m just a person in a small workshop. :person_shrugging:

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There’s been some dispute about this, but I saw some historical writing years ago saying that Maze was the first 3D first-person shooter. :slight_smile: What I recall is the dissenting opinion was that another game for the Plato system was first, probably called Spasim.

Hmm. From this description, I suppose the Alto setups are emulated, not using real Alto hardware under the desk. I notice the keyboards and mice aren’t original. You mentioned small PCs inside the monitor cases. I assume that’s also where the Alto emulation is going on, as well?

Almost makes me want to take another trip out to Mountain View, CA. :slight_smile:

Yes, the museum replicas are running the Contralto emulator on Fedora linux.

I wasn’t asked to build the processor cases or chording keysets, just the displays, keyboards, and mice. The keyboards and mice weren’t complete in time for the trip to the CHM. I was a bit bummed out about that because the whole thing feels more real with the correct keyboard and mouse. They’ll be ready for future events, though.

During the CHM event we had some of the original PARC programmers come in to walk down memory lane. A couple of them poked around to see if their code is still running in the emulator and were pretty happy to find that it is.

I was asked to build them to be a bit bomb-proof since they’re meant to be for hands-on use in museums where kids can bang on them and nerds can have fun hacking into them. They’re not as high fidelity as I usually like to build (e.g. there’s a USB port on the back!) so I may circle back and make a few more accurate replicas with the display, CPU case, keyboard, mouse, and chording keyset.

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Will you make any for sale?

Yes, my business is making replicas, exhibits, and other types of machines.

Do you have a way of copying the old media to some thing new?

But the first version of Maze ran on the Imlac PDS-1, not Alto. First at NASA Ames, then MIT.

Here’s how it went from MIT to PARC: Global Wahrman: How Mazewar Escaped from a Lab at MIT in 1977

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I am familiar with the basic outline of this history. I believe it was covered in Waldrop’s book, “The Dream Machine.”

If you’re referring to the Alto’s platters, I don’t personally have a reader but there’s a local guy who has a working Alto who I regularly bother. :joy_cat:
The Computer History Museum has a couple of working Altos that they use to read players into images they share.

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