[Piotr] was working on a recent Arduino project when he ran into a problem. He was having trouble getting his Arduino Pro Mini to communicate with an ESP8266 module. He needed a way to snoop on the back and forth serial communications. Since he didn’t have a specialized tool for this task, [Piotr] ended up building his own.
The setup is pretty simple. You start with a standard serial cable containing the TX, RX, DTR, and GND wires. This cable connects the Arduino to the ESP8266 WiFi module. The TX and RX lines are then tapped into. Each wire is routed to the RX pin of two different serial to USB adapters. This way, the data being sent from the Arduino shows up on one COM port and the data being transmitted from the module shows up on the other.
The next piece of the puzzle was coming up with a way to see the data more clearly. [Piotr] could have opened two serial terminals simultaneously, but this wasn’t ideal because it would be difficult to compare the timing of the data. Instead, [Piotr] spent less than an hour writing his own simple serial terminal. This one connects to two COM ports at the same time and prints the data on the same screen. The data from each COM port is displayed in a separate color to make it easy to differentiate. The schematic and source code to this project can be found on [Piotr’s] website.
We’ve all seen the cheesy hacker scenes in movies and on TV. Three dimensional file system browsers, computer chip cityscapes, and other ridiculous visualizations to make the dull act of sitting at a keyboard look pretty on the silver screen. While real hackers know those things are often silly and impractical, sometimes we do go out of our way to pretty things up a bit.
Hollywood might be able to learn a thing or two from this latest hack. [Yuri] modified his Linux terminal to change the color of the back lights on his laptop’s keyboard. It’s the kind of thing that actually would look good in a modern hacker movie, and [Yuri] is living proof that it’s something that a real-life hacker would actually use!
[Yuri] has been running Simple Terminal. The Simple Terminal project aims to build a replacement for the default xterm program that removes all of the unnecessary features and simplifies the source code. It also aims to make your terminal experience prettier. Part of making things prettier means that you can choose the font color for your terminals, and of course each terminal window can have its own color if you so choose.
[Yuri] happens to own an Alienware laptop. This laptop comes with RGB LEDs behind the keyboard, allowing you to light them up just about any color you could ever want. [Yuri] thought it would be cool if his keyboard color matched the font color of his terminal windows. Thanks to AlienFX, he was able to write a simple patch for Simple Terminal that does exactly this. Now whenever he selects a terminal window, the keyboard automatically switches colors to match the text in that window. Be sure to check out the video below. Continue reading “Simple Terminal Hack is Fit For Hollywood”
From time to time we realize that sayings which make sense to us probably will have no meaning for future generations. Two of the examples that spring to mind are “hang up the phone” or in a vehicle you might “roll down the window”. And so is the case for today’s Retrotechtacular. Linux users surely know about TTY, but if you look up the term you actually get references to “Teletypewriter”. What’s that all about?
[Linus Akesson] wrote a fantastic essay on the subject called The TTY Demystified. We often feature old video as the subject of this column, but we think you’ll agree that [Linus’] article is worth its weight in film (if that can be possible). The TTY system in Linux is a throwback to when computers first because interactive in real-time. They were connected to the typewriter-mutant of the day known as a teletype machine and basically shot off your keystrokes over a wire to the computer the terminal was controlling.
This copper pipeline to the processor is still basically how the terminal emulators function today. They just don’t require any more hardware than a monitor and keyboard. We consider ourselves fairly advanced Linux users, but the noob and expert alike will find nuggets and tidbits which are sure to switch on the lightbulb in your mind.
Retrotechtacular is a weekly column featuring hacks, technology, and kitsch from ages of yore. Help keep it fresh by sending in your ideas for future installments.
Ah, the VT100, the first dumb terminal that was controlled with a microprocessor. This ancient beast from the late 70s is quite unlike the terminals you’d find from even five years after its vintage – the keyboard connects via a TRS quarter-inch jack – the electronic and code design of this terminal is a bit weird. [Seth] was up to the challenge of making this mechanical keyboard work as a standard USB device, so he created his own USB adapter.
On the little quarter-inch to USB adapter, [Seth] included an HD 6402 UART to talk to the keyboard, along with a Teensy dev board and a few bits of circuits stolen from DEC engineers. The protocol between the keyboard and terminal is a little weird – first the terminal sets a bit in a status word, then the keyboard scans all the key rows and columns in sequence before telling the terminal it’s done. Yes, this gives the VT100 full n-key rollover, but it’s just weird compared to even an IBM Model M keyboard that’s just a few years younger.
[Seth] finally completed his circuit and wired it up on a perfboard. Everything works just as it should, although a little key remapping was done to keep this keyboard adapter useful for Mac and Windows computers. It’s a wonderful bit of kit, and any insight we can get into the old DEC engineers is a wonderful read in any event.
Continue reading “USB adapter for an old VT100 keyboard”
For how awesome Google Voice is, we’re surprised we haven’t seen this before. [Steve] is using Google Voice to run commands on just about any Linux box.
Google Voice doesn’t have an official API, and existing unofficial APIs weren’t up to snuff for [Steve]’s project. He ended up writing his own that checks his unread message inbox every minute and looks for new text messages beginning with the phrase, ‘Cmd’. If a series of checks pass – the text coming from a known phone number and a proper terminal command – the command runs and sends the a text back indicating success or failure.
While [Steve] probably won’t be playing nethack or Zork via SMS anytime soon, we can see this being very useful for a Raspi home automation task. Just send a text message and a properly configured Linux box can open your garage door, turn on the lights, or even start a webcam.
For a long time now, [Morgan] has been wanting an old serial terminal. In a stroke of luck, one of his pals at the Quelab hackerspace scored an awesome ADM-3A terminal from a collector. It’s a historically significant piece of computing and UNIX history, so obviously [Morgan] needed to get it working.
The ADM-3A terminal pre-dates the famous DEC VT-100 terminal, but since [Morgan]’s new acquisition speaks RS-232, he had a good shot at getting it to work with one of his more modern boxes. He’s using a Windows laptop loaded up with FreeBSD in a VM to talk to the terminal. Surprisingly, the only additional hardware required was a USB to serial cable and a DE9-DB25 serial adapter.
It may not be as cool (or as loud) as Quelab’s Teletype ASR-35 they have set up for Zork sessions, but it’s great to see ancient hardware have some
use. Right now, [Morgan] is editing files with vi and of course playing Zork. Seems like there’s plenty of life left in this old dumb terminal. After looking for an old VT-100 for a while now, I’ve got to say I’m pretty jealous.
Get serious about your shell scripting skills and maybe you can pull this one off. It’s a game of snake played in a BASH shell. It seems like a coding nightmare, but the final product turns out to be organized well enough for us to understand and took less than 250 lines of code.
[Martin Bruchanov] started on the project after pining for an old DOS game called Housenka. It’s another version of the classic Snake game which we’ve coded ourselves and seen in several projects including this head-to-head version using musical recorders as controllers. When using a terminal emulator capable of ANSI sequences the game is displayed in color using extended characters.
We give [Martin] bonus points for the way he wrote about his project. It describes the mechanics most would be interested in, like how the user input is captured and what drives the update function and food generation. The rest of the details can be gleaned by reading through the code itself.