The satisfying shutter on an old-school optical disk cartridge

A most satisfying “sliding shut” sound.

This morning, I noticed that this blog has been getting hundreds of additional pageviews coming from a Reddit post, and they’ve all been going to an article of mine from 2014: Old tech of the day: Optical disk cartridge and friends. In honor of the renewed interest in old removable storage tech, I present you with the video above, showing an optical disk cartridge’s shutter in action. Enjoy!

My 2014 article features pictures from an eBay listing for a 2.52 GB optical disk cartridge, which featured these photos:

These were mostly used in enterprise computing in the mid- to late-1990s, around the time when external storage technologies were exploding. Back then, I lived in Toronto and was a regular customer at CCBC — short for Computer Consumables Buyer’s Club — where I’d drop money on SyQuest cartridges (44 MB and 88 MB), Zip disks, Jaz disks, and CD-Rs, and look with curiosity at Bernoulli disks, EZ disks, and SparQ disks.

Do you have any online photos of old storage tech? Send me a link in the comments, and I’ll update this post and credit you.

Humor Programming

The real reason programmers prefer dark themes

Comic by monstika. Click to see the source.

R.I.P. David Boggs, co-creator of Ethernet

Let’s all take a moment to pay tribute to David Boggs, the electrical engineer and Xerox PARCer who co-created the local networking technology that we all know, love, and probably still use: Ethernet. He died at Stanford Hospital of heart failure on February 19th; he was 71.

Boggs’ replica of Bob Metcalfe’s concept drawing for what would become Ethernet. Source: IEEE 802.3 Working Group.

When Boggs joined Xerox PARC in 1973, he noticed a techie attempting to network their computers. That techie was Bob Metcalfe, whose name you might know from Metcalfe’s Law (“The value of a communications network is proportional to the number of network users, squared”) or from the company he co-founded (3Com). Together, over the next two years, they would create Ethernet, with Metcalfe being the concept person of the duo, and Boggs turning those concepts into working hardware.

Xerox PARC’s display of some of the original Ethernet gear.

The original Ethernet network was built in 1975 using coaxial cable and could transmit data at 2.94 Mbps. Ethernet has evolved since then, but the underlying principle is still the same:

  • Messages on the network are broken into packets, which are the unit of transmission on the network.
  • Packets are tagged with the ID of the destination computer.
  • Computers on the network on constantly “listening” to the network for packets tagged with their ID.
  • If a computer “A” on the network wants to send a message to another computer on the same network, “B”, it first checks the network to see if any other computer on the network is currently transmitting anything:
    • If another computer is currently transmitting something, wait a little bit (where “a little bit” is on the order of milliseconds).
    • If no other computer is transmitting anything, send a packet that’s marked with the destination computer, “B”.

When you say “Ethernet”, people usually think of this:

But that’s not Ethernet — that’s an CAT-n cable (it could be CAT-5 or CAT-6) with an RJ45 connector. You can also run an Ethernet network on a different cable, such as coax, or even using radio waves. You know radio-wave Ethernet by another name: Wifi.

Thank you, David Boggs, and requiescat in pace.