Ken Shirriff

@kenshirriff

Restoring a Xerox Alto. Reverse-engineering old chips. Added ₿ to Unicode. Fractals on a punch card computer. Charger teardowns.

Silicon Valley
যোগদান করেছেন মে ২০১০

টুইট

আপনি @kenshirriff-কে ব্লক করেছেন

আপনি কি এই টুইটগুলি দেখতে চাওয়ার বিষয়ে নিশ্চিত? টুইটগুলি দেখা হলে @kenshirriff অবরোধ মুক্ত হবে না।

  1. ২৫ জুন

    Not my most successful decap: tried to knock the lid off this CD4015 shift register chip from the 1970s with a chisel and the chip snapped in half. The round lid looks cool but doesn't come off cleanly like square ones. I put the pieces together to get a partial die photo.

    An old integrated circuit, accidentally snapped in half while trying to remove the circular lid to view the silicon die.
    An old integrated circuit with 16 pins and an unusual circular metal lid in the middle. The chip is labeled "RCA CD4015A".
    A die photo of the CD4015 shift register chip, showing the silicon chip and the metal traces on it. The die is cracked and missing a piece.
    পূর্বাবস্থায়
  2. ২৩ জুন

    Interesting "butterfly" patterns inside a chip from . These designs are balanced JFET transistors providing high-impedance inputs to this TL084 quad op amp. My detailed die analysis, along with an interactive chip explorer:

    পূর্বাবস্থায়
  3. ২১ জুন

    I used toggle switches to enter a prime-number program into a vintage IBM 1401 mainframe. Punch cards are the sensible way to load a program, but I did this for the /r/retrobattlestations Flippy Switch Week. Video is somewhat tedious:

    পূর্বাবস্থায়
  4. ৫ জুন

    Ever want to rate something 3 1/2 stars in Unicode? Now includes the half-stars that and I proposed almost two years ago.

    পূর্বাবস্থায়
  5. ১৯ মে

    The TI 76477 sound chip was popular with hobbyists in the late 1970s and used in Space Invaders. I reverse engineered it from die photos and explain how it works. It uses unusual digital logic called I2L, much denser than TTL. Details in my blog post.

    পূর্বাবস্থায়
  6. ১৯ মে
    পূর্বাবস্থায়
  7. ১৮ মে

    I'll be at this weekend along with and , using my microscope to explain what's inside chips. Stop by our booth and say hi if you're there!

    পূর্বাবস্থায়
  8. ৯ মে

    I'm giving a talk tonight about how to reverse engineer the first chip from die photos: how it is implemented in silicon and how to interpret the bitstream.

    পূর্বাবস্থায়
  9. ৯ এপ্রিল

    I implemented FizzBuzz the hard way, using an to generate raw video output. Got a bit carried away and added gratuitous rainbows and animation.

    পূর্বাবস্থায়
  10. ৬ এপ্রিল

    Gizmodo released a short video about 's computer collection: "Meet the Relentless Engineer Who Brings Vintage Computers Back From the Dead." Watch for our Xerox Alto, as well as me doing restoring stuff in the background.

    পূর্বাবস্থায়
  11. ৩১ মার্চ

    The disk drive failed on our vintage Alto. After extensive debugging of the drive controller (3 boards full of obsolete chips), we track down the problem: a loose wire on a motor.

    পূর্বাবস্থায়
  12. ২৬ মার্চ

    Ever wonder how your computer knows the name and resolution of your monitor? I use a board and the protocol to extract this data from a VGA monitor.

    পূর্বাবস্থায়
  13. ১৩ মার্চ

    I implemented FizzBuzz in digital logic using an . FizzBuzz is supposed to be a trivial programming problem, but implementing it in hardware is a different story. Using the Mojo dev board, I learned a lot about FPGA programming.

    পূর্বাবস্থায়
  14. ৭ ফেব

    Electric cars in space... Over 46 years ago the battery-powered lunar rover provided live video from the moon, viewable on a portable device. (Apollo 15, July 1971)

    পূর্বাবস্থায়
  15. ৭ ফেব

    The card reader for a 1960s IBM was a maze of gears and belts controlled by electro-mechanical relays. Debugging a malfunction was an adventure but we got it working.

    পূর্বাবস্থায়
  16. ৩১ জানু

    Quine scarves: the code on the scarf generates the scarf's design. I made the one on the right in Python.

    পূর্বাবস্থায়
  17. ১৪ জানু

    I took a vacuum tube module from a 1950s IBM , powered it up, and got it to operate. This 8-tube module from an IBM 705 business computer debounced keypresses from the console. Vacuum tubes = multiple high voltages = stack of power supplies.

    পূর্বাবস্থায়
  18. ১১ জানু

    Interesting component: "indicating fuse" from an IBM 1402 card reader (1959). When a fuse blows, the pin pops out, contacting a metal plate and lighting up the "Fuse" error light on the console. Also makes it obvious which fuse is bad.

    পূর্বাবস্থায়
  19. ৯ জানু

    Ethernet was invented for the Xerox Alto in 1974, but its original 3 Mb/s Ethernet is incompatible with modern Ethernet. I built a gateway using a to connect the Alto's Ethernet to the outside world.

    পূর্বাবস্থায়
  20. ৬ জানু

    I examined an IBM tube module from 1954. It implements five key debouncer circuits, cleaning up signals from console buttons. Built from eight dual triode vacuum tubes, it was part of the IBM 705 mainframe computer for business applications.

    পূর্বাবস্থায়

লোড হতে বেশ কিছুক্ষণ সময় নিচ্ছে।

টুইটার তার ক্ষমতার বাইরে চলে গেছে বা কোনো সাময়িক সমস্যার সম্মুখীন হয়েছে আবার চেষ্টা করুন বা আরও তথ্যের জন্য টুইটারের স্থিতি দেখুন।

    আপনিও পছন্দ করতে পারেন

    ·