Nebuchadnezzar Teardown

20140910       TerraHertz       http://everist.org

OK, the title is slightly misleading. I don't have the actual Nebuchadnezzar, hover-ship from The Matrix movie to pull apart. What I do have is a genuine prop from the shooting of the Nebuchadnezzar scenes. Though unfortunately it does not seem to appear on screen in the movie. Heh. If it did appear onscreen, I wouldn't be tearing it apart for mild curiosity, and possibly a few usable parts. I'd be selling it.

Anyway, here's how I came to have this  relic  piece of junk.
An acquaintance of mine used to work in an unlicenced nightclub in the inner city of Sydney. It was in a building on the Eastern side of Wattle Street, near Wentworth Park. I forget the exact address, but think it was here, on the corner of Wattle and Wiliam Henry St. The building was about 6 stories high, very old, and contained a great assortment of assorted tennants and empty spaces. The building owners suddenly decided they wanted to knock it down to construct new appartments. All the tenants received one month notice to vacate.

I only heard of this in June 2005 when my acquaintance mentioned to a group of us that the nightclub he worked for had finished moving out everything they wanted, and he'd been given permission to salvage anything left there that he wanted. He was owner-building a house for himself in the Blue Mountains, mostly of salvaged materials. He extended a general invite to all of us to come along for a salvage free-for-all.

It turned out that the entire building was in that same state. All the businesses had finished moving out, and left anything they didn't want. The entire place was full of 'acquaintances' sifting through the rich pickings. It was a lot of fun. My most useful find was the entire floor of a dance studio. The owner had unscrewed and stacked all the big sheets of nicely stained chipboard, then decided 'ah stuff it, better to buy new' for their next premises. I met the Japanese dance studio owner there one day, and asked him if he wanted the old flooring sheets at all. He said no, they're yours. It took a couple of trips to remove them all, and they now serve as the shelving in my main storage space. Here's some being put to use in 2006:

It surprised me to learn that one floor of the building had been used as a film studio set during shooting of The Matrix scenes inside the Nebuchadnezzar years before. They'd left a great deal of the props there, discarded and now definitely abandoned. Most of these got taken by others, but I grabbed one piece. It wasn't anything I recognized from the movie, but had that 'grunge of centuries' look of the Nebuchadnezzar.

It's been lurking around here ever since. I once tried ebaying it, but there was no interest. 'Not on screen', sigh.
Now I'm trying to purge useless stuff, and came across it again. Curious — I have no idea what this actually was. Some kind of electronic musical instrument? Then what is with the QWERTY keyboard? Not that it's possible to read the key legends under the painted on 'grunge'. There's no maker's name or model number visible anywhere.

So I opened it up. Which didn't solve the mystery at all. Does anyone recognise what this was?

First glimpse inside. Hmmm... the ICs are socketted. So that's some more ICs for my stock at least. The switches will be useless due to the paint.

Then the big surprise. What? But that's... core memory? All eight bits of it, and using common (big) ferrite torroids as cores. With a keyboard wired up (probably) so each key produces a different binary value in that 8-bit register. How very bizarre.
Thinking about it a little more, no, it's not a core memory register as such, but eight separate pulse transformers. There's a multi-turn sense winding on each torroid, so the 'values' produced by a key press are just transient spikes from the selected torroids.
Still a rather clever way to do the encoding.

What a collossal pain that would have been to wire up. Not so bad compared to the Apollo guidance computer 'roms', but still, a pain. Someone was really determined to binary encode a lot of buttons. When was this made I wonder? If I'm reading the date codes on the ICs right, about 1978. The same year as Intel's 8086 was released. I guess that explains why there is no microprocessor in this thing.

The keyboard really is wired up as 'each key shorts one wire to ground'. Lots of wires.

Quite a neat layout. There's a pencilled "#25" near the top edge of the PCB. Urrgh... So someone wired up at least 25 of those core encoders. Glad it wasn't me. I assume this may have been made in Australia, and around that time I was starting employment here as an electronics technician. If I'd been roped into this particular production hell I think I'd have quit electronics and become an arborist or something.

The front panel legends are barely legible. The two left rockers are Recirc/Norm and Hold/Run. The display (grunged) is Buffer Status, and the light below it seems to say "60 CH". Then there's Reset, Speed, Weight, Vol, and Pitch. Switch and light at the right are Power.

Definitely a sound generating instrument of some kind. But what exactly?
Not sure I care to try powering it up, given the high chances it isn't working and no idea of how it's supposed to work.

Ah ha! I found a model number under the paint on the front panel. "AERCOM CKB-4"
Wouldn't you know it, Google fails. "Your search - "AERCOM CKB-4" - did not match any documents."
Neither do fragments turn up anything useful.

This thing is gone, gone in the mists of pre-Internet undocumented small company products. As the Nebuchadnezzar is gone in the mists of distant future fictional worlds.

Discussion here: http://www.eevblog.com/forum/reviews/teardown-part-of-the-nebuchadnezzar-(the-matrix)/