Homebrew 68K Micro-ATX Computer Runs Its Own OS

March 27, 2021 by Tom Nardi 23 Comments

We’re no stranger to home built Motorola 68000 computers here at Hackaday, but more often than not, they tend to be an experiment in retro minimalism. The venerable processor is usually joined by only a handful of components, and there’s an excellent chance they’ll have taken up residence on a piece of perfboard. Then [NotArtyom] sent in his Blitz, and launched the bar into the stratosphere.

Make no mistake, the Blitz isn’t just some simple demo of classic chips. The open hardware motherboard has onboard floppy, IDE, and PS/2 interfaces, with a trio of 8-bit ISA expansion slots for good measure. The Motorola 68030 CPU is humming along at 50 MHz, with 4 MB of RAM and 512 KB of ROM along for the ride. Designed to fit the Micro-ATX motherboard standard, you can even mount the Blitz in a contemporary PC case and run it on a standard ATX power supply.

An earlier prototype of the Blitz motherboard.

As if the hardware wasn’t impressive enough, [NotArtyom] went ahead and created his own open source DOS-like operating system for it to run. Written in portable C, G-DOS can run on various m68k boards as well as ARM and PowerPC machines. It’s an incredible project in its own right. If you’re looking for something to show off your homebrew computer, you could certainly do worse than pulling down a copy of G-DOS. If you do port it to a new board, make sure to let [NotArtyom] know.

It’s taken [NotArtyom] three years to develop Blitz and G-DOS with his only goal being to better understand homebrew computers. He has no interest in monetizing the design or turning it into a kit, but instead hopes it will be a resource and inspiration for others with similar interests. Oh yeah, and he did all of this before he even graduated high school. If you weren’t questioning your life’s accomplishments before, now would be a great time to start.

Interested in building your own Motorola 68000 computer, but haven’t yet attained the wizarding level of [NotArtyom]? You could start with something a bit simpler like the 68k-nano, or if you’re really in a pinch, just dead bug a Dragonball 68328.

Changing System Architectures And The Complexities Of Apple’s Butterfly Approach To ISAs

July 13, 2020 by Maya Posch 64 Comments

Apple computers will be moving away from Intel chips to its own ARM-based design. An interesting thing about Apple as a company is that it has never felt the need to tie itself to a particular system architecture or ISA. Whereas a company like Microsoft mostly tied its fortunes to Intel’s x86 architecture, and IBM, Sun, HP and other giants preferred vertical integration, Apple is currently moving towards its fifth system architecture for its computers since the company was formed.

What makes this latest change possibly unique, however, is that instead of Apple relying on an external supplier for CPUs and peripheral ICs, they are now targeting a vertical integration approach. Although the ARM ISA is licensed to Apple by Arm Holdings, the ‘Apple Silicon’ design that is used in Apple’s ARM processors is their own, produced by Apple’s own engineers and produced by foundries at the behest of Apple.

In this article I would like to take a look back at Apple’s architectural decisions over the decades and how they made Apple’s move towards vertical integration practically a certainty.

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