August 16th, 2008
I always have time to think while mowing the lawn. And today while mowing the lawn, I got the notion that it would be great fun to play Colossal Cave and other early text adventure games on a teletype. And, of course, since Linux has teletype support in its genes, if I played my cards right, I could probably get a login prompt to my workstation with the teletype, too.
Now, at this point, I am compelled to take a small diversion and explain just what a teletype is — for those of you, like me, who are too young to remember them. (I will graciously omit comment on those of you too old to remember them!) Teletypes have been around since about the 1930s or so, but the ones I have in mind are the ones that were used to interact with computers in the 1960s and 1970s. Instead of a keyboard and monitor, you’d have a keyboard and printer. Believe it or not, surplus teletypes were the interface of choice for teletypes even in the later years because they were so much cheaper than video terminals.
So anyhow, back to the plot. Teletypes operated at speeds ranging from about 40bps to 110bps, but it seems that the most common protocol was Baudot-coded 50cps 5N2 serial format — that is, 5 data bits, 2 stop bits. Amazingly, the serial UART in modern PCs is still capable of communicating with these devices (though it may take some circuitry to tweak the voltages), and at least one person has made it work with Linux.
So I zip on over to eBay to look for teletypes. What do I find? NOT A ONE! A few manuals, and apparently there is a GPS named the teletype. And some company that has something they think *might* be compatible with a teletype, but they don’t know.
eBay has sorely let me down. An antique geeky item should be right up their alley, and zilch. They can sell everything from cars to advertisements on some guy’s bald head, but not a teletype? C’mon!
So anyhow, I am afraid I will have to improvise. Perhaps I can find a dot-matrix printer with a serial port (or, I guess, a parallel port would do too) and an unbuffered printing mode. Then the trick would be getting keyboard input. Perhaps I could rig up a pty to do this, input from /dev/console, output to /dev/ttyS0. It would still be old, but not quite the real deal.
So if any of you have a working teletype you’d like to get rid of, do please let me know. I’ll send you a photo of the printout of me getting lost in Colossal Cave.
Oh, and for those keeping track at home, I guess you can add this to the list of old technologies I’m interested in: Gopher, typewriters, teletypes… they’re all alike, right?