Culture

Blast Off Into the Past: An Apple 1 Demo at the Vintage Computer Festival West

11 Aug 2019 6:00am, by

Apollo_11_lunar_module (by NASA).j

Last weekend, Mountain View’s Computer History Museum hosted the Vintage Computer Festival West, giving attendees a moment to cherish our common heritage with a carefully curated display of some remarkable artifacts – and to commune with the enthusiasts, the educators and the dedicated preservationists who are keeping it all alive.

With an eye to future generations, the festival was free for anyone 14 or younger, and is lovingly maintained by the Vintage Computer Federation, a 501(c)3 nonprofit.

“You’ll find demos of 1960s minicomputers, 1970s homebrew systems, 1980s eight-bitters, and a few oddities,” promised the festival’s web site.

“At the end of the day, preserving this technology and sharing it with future generations is really what it’s all about,” wrote the technology site Hackaday, one of the event’s sponsors, along with the Association for Computing Machinery, the IEEE and the Computer History Museum.

Bil Herd, one of Hackaday’s video contributors, is also the former chief designer of the Commodore 128, and gave a talk on how time affects a vintage computer’s internal components.

Welcome to Your Past

This was the nonprofit’s third festival of the year, after events in New Jersey, Washington and Italy. But hopes for this Silicon Valley edition seemed especially high. There were lots of enthusiasts and lots of enthusiasm, judging by the event’s page of exhibitors, which provided more than 100 vintage computer demonstrations. Highlights included:

  • Software developer Chris Davis demonstrated his vintage computer recreations (assisted by Gabe and Eli Davis) including an Altair 8800 based on the Arduino Duo and a modern replica of the Apple I.
  • Senior technology executive Simon Wynn demonstrated a fully restored Sun Microsystems IPX, a Sparc-based UNIX workstation from the early 1990s — which originally sold for $11,995.
  • Michael Furman from San Jose demo’d one of Radio Shack’s 1980s-era TRS-80 Color Computers — and touted its ongoing development by enthusiasts.
  • Brian Parker from Redwood City, California, talked about efforts to build a half-scale recreation of a famous computer from the 1830s: Babbage’s Analytical Engine.
  • The San Leandro Computer Club brought its original Atari 400 & 800 computers — first released in the late 1970s — along with all the peripherals (including “Star Raiders,” the world’s very first, first-person shooter game, and all of the other original Atari titles). And they even demo’d their machines in an original kiosk that had actually been used by Atari at C.E.S. — complete with a copy of the original interactive demo software.
  • There was also a demonstration of a DEC PDP-1 (first produced in 1959).

And someone even spotted an Enigma decoder. The museum itself provided one exhibit that caught the attention of the Apple bloggers at the Cult of Mac site.

“You would have to ride in a time machine back to 1976 and that garage on Crist Drive in Los Altos, Calif., to find 10 Apple 1 computers in the same space,” David Pierini wrote last week on the site. The post also notes that the Apple 1 Registry reports that only 200 were ever built — and reported that at least five of the computers were expected to be actually running.

There were two different presentations to put this historic event in the proper context – and one even included a remarkable interview with Liza Loop, the owner of the very first Apple I, personally given to her by a 26-year-old Steve Wozniak.

In the same talk, Apple 1 expert Corey Cohen also demonstrated an actual Apple 1 that was flown over from Germany, and provided some history. (Rather than loading BASIC from an original-era cassette player — which would take 20 minutes — Cohen swapped in a modern iPad.)

There was some real tension in the room — since this particular Apple 1 hadn’t been run in over a year. “Okay, who has the fire extinguisher,” Cohen joked…

Cohen had hoped to adapt the Apple 1’s video output — which was “close” to analog — for a large presentation screen. But unfortunately, while the Apple 1 was working, the video adapter wasn’t. Next he tried hooking up a small Sanyo monitor, and then filmed its tiny display. Future Apple employee No. 12 Daniel Kottke joined him on stage, typed in 0.F to see if it would list memory – and it did.

50 minutes into the presentation, Cohen was finally able to show the audience the Apple 1’s BASIC prompt — explaining to the audience he had to type very carefully.

And then he ran a program which prints out “HELLO VCFHELLO VCFHELLO” over and over again — drawing a round of applause from the audience.

HELLO VCF - Corey Cohen demos an Apple 1 at VCF West 2019

“If you can get that far, believe it or not, that adds hundreds of thousands of dollars to the value of an Apple 1,” he said.

He finished with a demo which printed out primitive two-color images — first of Woz, and then of Steve Jobs, and then of Woz and Jobs together, and eventually the Apple logo.

Woz image on an Apple 1 - Corey Cohen demos at VCF West 2019

Kottke later demonstrated a program which allows an Apple 1 replica to send email. And Cohen also moderated a panel of Apple 1 owners — along with some of the earliest Apple employees.

The Computer On The Moon

Mankind’s “primitive” early computers accomplished some amazing things. In a special presentation, computer restoration expert Mike Stewart actually demo’d an official NASA Apollo Spacecraft Program simulation program — basically, the original software, though it normally just sends its output to a simulator. Instead he plugged it into one of the debuggers they’d use for restoring an actual Apollo Guidance Computer — and then used that to feed signals to their “gate-accurate replica” of the original 1969 computer. “So now I have to do a workaround for a bug in the Apollo 11 software,” he said at one point. Restarting the computer makes the software lose track of its landing radar.

He also told the audience that even reading the codes off of the display came with its own challenges: “The astronauts had to memorize the location of the decimal point in every display, because the display doesn’t have any points in it.” And one of the most exciting moments comes when the Delta H number reports that the landing radar’s readings conflict with those from the Apollo Guidance Computer. “What this is saying right now is that we are 4,000 feet lower than the AGC thinks. Which is a problem for the landing… The computer’s going to send us right into the surface at this rate.”

The solution? Typing “Verb 57 Enter," which switches over to the landing radar’s measurements. “We’ll see the Delta-H slowly countdown as the AGC slowly incorporates the radar readings into its idea of where we are.”

A half century later, that code is now available on GitHub, but it was nice to see an audience watching it as it runs, and applauding as the simulated module landed on the moon and its engine stopped right on time.

“And so now we are on the surface of the moon,” Stewart said. (More applause.) “That’s how we fly an Apollo 11 landing.”

But then he hits an “abort state” button to blastoff back into orbit.

Meanwhile, RR Auctions was actually selling both an Apple 1 and an Apollo Guidance Computer — and brought them both to the show to “preview” them before the upcoming auction.

Building a New Keyboard For A Mainframe

Dave Babcock from the museum’s IBM 1620 Jr. Project gave a presentation on how his team had taken a commercial IBM Lexmark Wheelwriter 1000 typewriter — and then created a general-purpose terminal keyboard that works with vintage computers. For example, it can double as the console typewriter for the massive IBM 1620 from 1959 — or function as an ASCII teleprinter.

They overcame the innumerable challenges with cleverness and pluck — including a hack that involves “injecting” fake key-presses into the typewriter’s logic board. It will also come in handy in the future, since the museum is recreating the IBM 1620 mainframe, creating a sturdy historically-accurate re-creation that the museum’s visitors can interact with. It required a console typewriter to input its machine-language boot instructions.

“Our goal is that this is a general-purpose teleprinter,” he said, during a Q&A session at the end. “It can replace a teletype or any other teleprinter, to work with any computer with an RS2/ASCII kind of thing.”

IBM 1620

The IBM 1620.

Ultimately the festival gave them the perfect chance to test their device with more machines. They’ve plugged it into PCs, Macs, a Raspberry Pi, a PDP-8/i, a replica of an Altair 8800 — and each new device allowed them to tweak and customize their hybrid of past and present just a little bit more.

In the true spirit of the festival, they made a special offer to anyone who’d come out to enjoy this great gathering of vintage computers.

“We’ve had a deal here at the show, where anyone with a computer with an RS2 — bring it over and plug it in!”


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