Earlier this year, programmer Justin Ouellette picked up an 11-inch 1983 VT220 terminal and, after a little bit of wrangling, got it to display the command line for his 2010 Mac Pro, running 2011 OS X Lion.
If you are of a certain age, you might remember banks of these glowing amber text terminals in your university’s computer lab. If you worked in the right kind of office, you might have had one on your desk. These were dumb terminals, effectively teletype machines that communicated with a hulking central mainframe that lived in some isolated server room somewhere. That back room beast did all of the work, and it was running UNIX.
Today, UNIX is everywhere. Most web servers run on it. On the desktop it is the basis for Linux and OS X. On phones, it’s at the heart of iOS and Android. There is an unbroken chain of evolution that connects these modern devices to the first UNIX implementation, released in 1969. Back then, the machine was programmed using punchcards. In the early '70s we’d switched to teletype machines which printed the output on paper. As applications became more interactive, it became clear that video terminals (which could display faster and didn’t generate reams of waste paper) would be superior. The VT100 was released in 1978 and Ouellette’s VT220 was released in 1983. When you run the command line, you are running software emulation of those terminals.
With a little bit of work, Ouellette managed to get his tiny CRT running without any emulation at all.
"I think it’s cool when hardware still works perfectly decades after it’s introduced, even if it’s not quite as practical as a virtual window on your screen. I actually like switching over to a completely different device when it’s time to do some low-level textual interaction," says Ouellette.
He continues to use the terminal, mostly for grabbing or committing code on git and subversion. He says he’s heard from six people who have managed to replicate the setup and he has a standing offer to help anyone else who wants to dabble in the roots of modern computing.
"We didn’t get to where we are overnight, user interfaces and software development have been evolving in an unbroken chain for a long time and some of the old ideas are so solid that they persist 30 years later," Ouellette says.
Indeed, they persist for longer, still. The VT220 runs with 80 columns of text per line. That width is a legacy of the punchcard programming that came before. The format for those cards was designed by IBM in 1928.