JWZ documents his adventures in bringing a 1982/3 vintage Ann Arbor Ambassador 60 terminal (a rare portrait-orientation terminal) back into service -- fitting it with a Raspberry Pi and a new power-supply and getting it to boot its beautiful green-screen.
I don't remember how I ended up with it -- I probably liberated it from work some time in the late 80s. But it served me well.
At one point, I built a 50' serial cable so that I could drag the terminal out onto the back deck and work outside. I remember also routing audio for a headphone jack over some of the unused lines inside that cable, since I didn't have speakers outside.
An elegant cable, from a simpler age.
Here's the problem with this device, as you can see in the video: the character buffer on the serial port is not large. I'm guessing it is dozens of bytes deep. Dozens. And the CPU that moves those bytes from the serial port into display memory is... not fast. So it keeps up pretty well at 4800 baud, but at 9600, or when you light up the afterburners and go for the full 19,200, it falls behind.
The way terminals deal with this is flow control: either end can say, "Hold up, I am suffering" and data transmission stops until the other side is ready. The proper way to do this over a serial connection is with DSR/DTR lines, which are extra copper on the RS-232 cable, one for each side, that signal when we're ready to go. But as noted, the not-quite-a-serial-port that Pis have doesn't have that. Which leaves you with inline flow control, XON and XOFF, typically the ASCII bytes ^S to stop and ^Q to resume.
You guys, I got my Ono-Sendai working again!
[JWZ]
There’s still magic in the world, as evidenced by this fairy’s-eye view of Children’s Fairyland, that charming 70-year-old storybook theme park in Oakland, California. You might remember that when I’m not blogging, I work with Fairyland. WELL… months before we were mandated to shelter in place, a local photographer, Stephen Loewinsohn, contacted our team at […]
We’ve been writing about Lea Redmond since 2009 here on Boing Boing. She’s just one of those kind of people who consistently makes neat things — a real Happy Mutant! Well, her latest creative venture is Home Sweet Home, an activity deck for kids (and the young at heart). It offers inspiring prompts for whimsical, […]
Listed at $159,900 this 1,075 square-foot home in Pittsburgh, Pennsylvania is bland on the outside but features rooms with outer space, submarine, tropical island, and moonbase motifs. The owners put a lot of work into it!
Apple AirPods have become the default earbuds beloved by millions. Unfortunately, they also cost $159, so it’s no surprise that since they were first introduced in 2016, companies have battled to produce comparable headphones at a lower price. The UK-designed and engineered Veho STIX true wireless earphones may have cracked that particular problem, striking a […]
Instagram isn’t just for tweens and foodies. In fact, the image-heavy platform not only wants to mint new Instagram influencers — it also wants to make them rich. In the last few weeks, the company announced ad revenue sharing on IGTV videos, special badges you can buy from your favorite accounts through Instagram Live, merchandise […]
There’s a case to be made that animation might be the most labor-intensive storytelling method out there. For every second of finished film, animators have to create 12 different moving character images, each minutely adjusted to give the illusion of fluid motion. And that’s in addition to the background drawings and any other elements needed […]
