did you know that just 5 miles from the shining skyscrapers, the overpriced single family homes, and the congested freeways of Silicon Valley is a real, bona-fide 19th century ghost town? 🧵
it's called Drawbridge, California, and it was built around a railroad drawbridge located in wetlands out in the middle of the San Francisco bay.
it all started when the original drawbridge was built in the 1880s. in the days before remote control, a tender had to live onsite and operate the bridge, opening it for ships and closing it for trains.
the wetlands were home to countless waterfowl and became a popular hunting spot, and since the railroad had a stop next to the tender's house, it became a convenient place for hunters to embark. entrepreneurs began to build hunting lodges and gun clubs, and the town was born!
because the town was never formally incorporated, it never had police. it was like the wild west! in the 1920s, lots of illegal activities happened here in broad daylight.
the town was right on the county line, so Santa Clara county sheriffs didn't want to deal with it, but neither did Alameda county! it didn't help that the residents were armed to the teeth (for hunting purposes, naturally).
in the '30s and '40s people started to leave the town because...of the smell. at that time the city of San Jose was dumping raw, untreated sewage into the bay, and it stank! it also didn't help that the houses, which had to be built on stilts, were slowly sinking into the muck.
but the town didn't die right away--the last resident left in 1979!
if you want to read more stories about Drawbridge and see some neat old pictures, check out "The Soft Underbelly of San Jose" at sanjose.com/underbelly/unb…
someone else found an excellent video about it, with interviews and some great drone shots.
a short but highly technical history of DRAM - dynamic random access memory! 🧵
but first: dynamic?
static - a logic circuit that operates down to 0Hz clock.
dynamic - a logic circuit with a minimum clock frequency.
static RAM is made of two cross-connected inverters along with two pass gate transistors that connect and disconnect the memory cell to the bit lines. you need 6 transistors to make a cell that can store one bit of information.
it's Black history month! this is Dr. Mark Dean, who worked on the design team of the original IBM PC. he worked on the design of the CGA card--his name is on two patents around generating composite video.
he was at the start of his career, in his early 20s, when he did this. later, he studied at Stanford University and received his PhD, then did more amazing work at IBM, ending up with the prestigious title of IBM Fellow!
i have a theory about the name of the iconic Roland TR-808 drum machine. the "TR" part stands for Transistor Rhythm but where does the 808 part come from? 🧵
but before we get to that, we need to talk about the Hammond Organ.
the Hammond Organ was a very unique instrument invented in the 1930s, and it was one of the first instruments you could call a synthesizer.