A Love Letter To My Lost Amiga

My first love was a black wedge. It was 1982, and I had saved up to buy a Sinclair ZX81. That little computer remains the only one of the huge number that I have owned over the years about which I can truly say that I understood its workings completely; while I know how the i7 laptop on which this is being written works I can only say so in a loose way as it is an immensely complex device.

Computing allegiance is fickle, and while I never lost an affection for the little Sinclair I would meet my true electronic soulmate around eight years later as an electronic engineering student. It no longer graces my bench, but this was the computer against which all subsequent machines I have owned would be measured, the one which I wish had not been taken from me before its time, and with which I wish I could have grown old together. That machine was a Commodore Amiga, and this is part love letter, part wistful musing about what could have been, and part rant about what went wrong for the best desktop computer platform ever made. Continue reading “A Love Letter To My Lost Amiga”

The Physics Behind The Collapse Of A Huge Aquarium

At the end of last week Aquadom, the world’s largest cylindrical aquarium, unexpectedly shattered and caused an emergency as it flooded both the Berlin hotel that housed it and the surrounding streets. From an engineering perspective it’s a fascinating story, because its construction was such that this shouldn’t have happened. We have an analysis of what might have gone wrong from [Luis Batalha] (Nitter), and from it we can learn a little about the properties of the plastic used.

The aquarium was made of an acrylic polymer which has an interesting property — at a certain temperature it transitions between a glass-like state and a rubber-like one. Even at room temperature the acrylic is well below the transition temperature, but as the temperature drops the acrylic becomes exponentially more brittle. When the outside temperature dropped to well below zero the temperature also dropped in the foyer, and the high water pressure became enough to shatter the acrylic.

Sadly few of the fish from the aquarium survived, but fortunately nobody was killed in the incident. News coverage shows how the force of the water destroyed the doors and brought wreckage into the street, and we’re guessing that it will be a while before any other hotel considers such a project as an attraction. Meanwhile we’ve gained a little bit of knowledge about the properties of acrylic, which might come in handy some day.

Header: Chrissie Sternschuppe, CC BY-SA 2.0.

See The ATARI GEM Desktop Running On A Portable Word Processor… Thing

Get ready for vintage computing aplenty in [David Given]’s project to port EmuTOS to the AlphaSmart Dana. He’s got it all on video, too. All 38 hours of it over 13 episodes!

The GEM desktop, as seen on the Atari ST line of computers.

[David]’s fork of EmuTOS is an open source version of the Atari TOS, which is itself the 68000-based OS for the Atari ST line of computers.

As for the AlphaSmart Dana, it is a roughly twenty-year-old portable word processor thing with pen input which runs a version of PalmOS. It’s a slightly oddball piece of hardware, but quite capable in its own way. A match obviously made in heaven? It is if you have [David]’s skill and drive!

To get EmuTOS working on the Dana, the first step was figuring out how to find and work with the Dana’s debug port, using it to get direct access to the CPU while bypassing the boot ROM. Turns out that the Dana’s 68000-compatible processor has a handy feature: by manipulating the right pin, one can remote-control the CPU (to a certain extent) via the UARTs. That’s the entry point for a whole lot of hacking that ultimately results in firing up the GEM desktop on the Dana, and being able to run (some) original Atari ST software. Probably the biggest issue is that the screen size isn’t a great match for what the OS expects, but it works.

Continue reading “See The ATARI GEM Desktop Running On A Portable Word Processor… Thing”