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Move Over, Arduino: Here Comes the Cosmac Elf

A modern version of a 1976 computer may be surprisingly useful

5 min read
Move Over, Arduino: Here Comes the Cosmac Elf
Photo: Randi Klett

Regular readers of this column may have noticed that I have a fondness for  newtakesonold technologies. So you won’t be surprised that when I came across Lee Hart’s Membership Card kit, I leapt at the chance to build it. The Membership Card is a modern version of the 1976 Cosmac Elf. The Elf was an influential early microcomputer built around RCA’s CDP1802 processor. What may be more surprising is that the Membership Card might be just the ticket for modern makers looking to build microcontroller-based devices that can run for a year on a few AA batteries.

The original Elf dates from the heroic age of personal micros, a time before QWERTY keyboards and bitmapped displays became standard and made us all soft. Input was via a set of toggle switches, hand-setting each bit in a byte. You wrote programs in pure machine code. You read the output via a two-digit LED display capable of showing one hexadecimal digit apiece, plus one additional so-called Q LED. The Membership Card is even more severe on the output front than the original: “Numeric” output is via a row of eight LEDs that display a byte in binary. You can’t get closer to raw computation without an erasable marker and a really long piece of tape.

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From WinZips to Cat GIFs, Jacob Ziv’s Algorithms Have Powered Decades of Compression

The lossless-compression pioneer received the 2021 IEEE Medal of Honor

11 min read
Photo of Jacob Ziv
Photo: Rami Shlush

Lossless data compression seems a bit like a magic trick. Its cousin, lossy compression, is easier to comprehend. Lossy algorithms are used to get music into the popular MP3 format and turn a digital image into a standard JPEG file. They do this by selectively removing bits, taking what scientists know about the way we see and hear to determine which bits we'd least miss. But no one can make the case that the resulting file is a perfect replica of the original.

Not so with lossless data compression. Bits do disappear, making the data file dramatically smaller and thus easier to store and transmit. The important difference is that the bits reappear on command. It's as if the bits are rabbits in a magician's act, disappearing and then reappearing from inside a hat at the wave of a wand.

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