DIY CPU Demo'd Running Minix 313
DeviceGuru writes "Bill Buzbee offered the first public demonstration of the open-source Minix OS — a cousin of Linux — running on his homebrew minicomputer, the Magic-1, at the Vintage Computer Festival in Mountain View, Calif. The Magic-1 minicomputer is built with 74-series TTL ICs using wire-wrap construction, and implements a homebrew, 8086-like ISA. Rather than using a commercial microprocessor, Buzbee created his own microcoded CPU that runs at 4.09 MHz, and is in the same ballpark as an old 8086 in performance and capabilities. The CPU has a 22-bit physical address bus and an 8-bit data bus."
Minix was Sire of Linux (Score:4, Informative)
Linus copied Minix. Well known fact !!
Self flagellation (Score:4, Informative)
Re:cousin? (Score:5, Informative)
The schematics are online, and yes, it networks (Score:4, Informative)
Re:Is there a kit version? (Score:3, Informative)
Re:But does it run.... ? (Score:5, Informative)
Re: not online because on display (Score:4, Informative)
Re:cousin? (Score:2, Informative)
Minix back then was open source (non-TM version) but you had to buy the textbook to legally use a copy. Now it's open source and the latest version is quite respectable.
It does have an ethernet device! (Score:1, Informative)
It is, apparently, slashdotted right now just through people following the chain of links and finding it.
How much slashdotting does it take to take a 4 MHz machine to it's knees?
And more importantly, did it stay UP during the slashdotting, but just get as slow as Unreal on a 100 MHZ machine w/o 3D-hardware acceleration?
Re:Doomsday paranoia (Score:1, Informative)
Re:DIY PC... (Score:1, Informative)
Re:Why not PCBs? (Score:3, Informative)
In small quantities, they're more expensive than wire-wrap, although it depends on what your time is worth. Of course you can spend your time laying out a PCB or spend it doing wire wrap. I'd do the PCB. Especially if I needed more than one.
I think the guy did it with wire wrap because it's retro. Hey, whatever floats yer boat.
Re:Coolest, dude ... ever... (Score:3, Informative)
Re:The blinky lights... (Score:3, Informative)
Re:Coolest, dude ... ever... (Score:3, Informative)
I know that a few instructions (the branching slot) only works on a pipelined implementation, but it isn't necessary to make a fully compatible MIPS.
And even a 'basic x86', is quite complicated with its instruction with a varying length..
more than that!!!!1 (Score:5, Informative)
Windows copied Macintosh, which copied the Lisa (also from apple), which copied the Xerox Alto and Star, which copied the oNLine System (1965).
If by "copied" you mean "got ideas from." In science this is not considered cheating. It is considered doing your homework. If you don't look at other successful designs before making your own, there can be no progress. We'd end up reinventing the wheel 100 different broken ways, instead of coming up with better and better iterations on the same theme.
Linux was "inspired" by Minix, but succeeded in its place because of higher performance and a more open development environment.
Re:Minix was Sire of Linux (Score:2, Informative)
From: torvalds@klaava.Helsinki.FI (Linus Benedict Torvalds)
Newsgroups: comp.os.minix
Subject: Free minix-like kernel sources for 386-AT
Message-ID:
Date: 5 Oct 91 05:41:06 GMT
Organization: University of Helsinki
As I mentioned a month(?) ago, I'm working on a free version of a
minix-lookalike for AT-386 computers. It has finally reached the stage
where it's even usable (though may not be depending on what you want),
and I am willing to put out the sources for wider distribution. It is
just version 0.02 (+1 (very small) patch already), but I've successfully
run bash/gcc/gnu-make/gnu-sed/compress etc under it.
Yes, he did not copy it in the sense of copying an mp3, but he started on minix and wanted something similar.
Re:Doomsday paranoia (Score:3, Informative)
It's surprisingly easy to draw wire. I've done lots of it. The original stuff was done without drawplates: they filed a notch in a plate, then put a second plate against it, clamped them firmly, and pulled, then used the next, smaller notch. You get a half-circle of wire that tends to curl but it's doable. Insulation is *much* harder -- making something that's flexible, tough, and has a reasonable dielectric, and getting it to stick to the wire, is *hard*. Drawing 30 gauge copper tubing is easy in comparison.
Voltaic piles are easier to make than Leyden jars. If you're bored, you can light an LED with a stack of small pieces of aluminum and pennies, separated by lemon-juice-soaked paper towels. It took me about 7 of each to get a red LED to light. If people had known what to do they could've made voltaic pile batteries in Egyptian times -- separate copper and silver chunks with spit- or saltwater-soaked papyrus sheets.
There were early relays made from glass tubes with wires and piles of steel filings. An electric charge on one wire attracted filings, which bridged to the other wire. You could use those to make primitive high-power diodes as well, by messing with the geometry of the wires -- again, stuff that any culture with some competence in glass could've done (and that's pretty old.) The problem was always one of basic research and not knowing what to try.
Tubes aren't THAT easy to make.... (Score:4, Informative)
While tubes are simple in concept, the amount of chemistry, metallurgy, and material science that went into making reliable vacuum tubes was simply astounding. Particularly for applications involving hundreds or thousands of tubes (like computers), achieving very high tube reliability is key to getting the computer to run long enough to actually crank outa few calculations before a tube fails.
Tubes that were designed for computer service needed ultrahigh purity metals, particularly nickel for the cathodes. The level of vacuum needed is FAR higher than you could get with a simple mercury siphon pump (think turbomolecular or oil diffusion pump). Exotic metallurgy and coatings are needed to produce grids and plates that don't emit their own secondary electrons. Cathode coating chemistry was jealously guarded by most manufacturers, and also critical to decent life.
All of this stuff is pretty much a "lost art" these days, and it is likely that nobody will EVER be able to duplicate the quality of the best tubes of the past, as most of the people who did it are now dead. While you can make a triode that will function as an amplifier with rudimentary glassblowing skills, making a tube that will reliably work in a high speed pulse switching environment such as a digital computer takes a great deal more knowledge and infrastructure.
Tube manufacturing was every bit as complicated as semiconductor manufacturing is today.