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February 26, 2021 Archives
Friday, February 26, 2021
CONTINUITY: 1959—IBM 1401 Product Announcement
The IBM 1401 was a small (for the time) transistorised computer intended for business applications, where it would replace punched card machinery. It also served as an input/output processor for larger systems, offloading the overhead of directly driving card readers, punches, and line printers. More than 12,000 1400 series computers were sold, and the system remained in production until 1971.
This is a film recording of a nationwide closed circuit television product announcement from IBM, introducing the 1401 and its peripheral devices, including the IBM 305 RAMAC disc storage device.
Posted at
16:30
CONTEXT: Fusion and Magnetic Reconnection Propulsion
A plasma thruster, which can be powered by any source of electrical energy, exploits the same electromagnetic field configuration which causes solar flares to create substantial thrust with exhaust velocities between 20 and 500 km/sec (the best chemical rockets produce around 4 km/sec). Here is the paper describing the thruster: “An Alfvenic reconnecting plasmoid thruster”.
Face it: “Alfvenic reconnecting plasmoid thruster” sounds like something right out of Doc Smith!
Posted at
12:57
TRACKING WITH CLOSEUPS: Top Ten Craziest x86 Instructions
The Intel x86 “architecture” (if you can call it that) is the most amazing collection of bags hanging on the side of bags bulging with kludges hacked over a long history of providing absurdly complicated instructions almost nobody uses lest their code not run on older processors that don't implement them. Here are some of the most egregious examples.
I have actually used one of these instructions: can you guess which? I remember giggling when I learned the Univac 1107 had an instruction called “Magnitude of Characteristic Difference to Upper”. Imagine the progress that fifty years would bring!
Posted at
12:19