The Return of the VT100

Alasdair Allan
2 min readNov 24, 2017

From the mid-seventies all the way through until late-eighties, or perhaps even the early-nineties, if you walked into a computer lab you’d come across a VT100 terminal. Towards the end there might have only been one or two wedged quietly in a corner, but they were there.

These beige boxes were ubiquitous, and they survive today, at least in a way. Every time you open a terminal window on your laptop, you’re using a piece of software that emulates the extended set commands that originated with the VT100 hardware. Go ahead and enable the serial console on your Raspberry Pi, and you’re talking these protocols over an RS-232 serial connection—yet another protocol that has survived from the dark ages of computing more or less intact.

Enter the diy-VT100 terminal coming soon to Crowd Supply.

The diy-VT100. (📷: Mad Resistor)

The diy-VT100 is compatible with the VT100 and VT102 standard protocols, emulating a lot of the original features of the terminal including the seven LEDS that used to sit just above the keyboard—ONLINE, LOCAL, KBD LOCKED, L1, L2, L3, L4—and the original 800Hz BELL sound. Just like the original VT100, and the Terminal window on your laptop, it has a 80×24 character display.

The diy-VT100. (📷: Mad Resistor)

However unlike the original VT100 it’s built around an ARM Cortex M7 microcontroller, a STM32F767. It’s small, portable, and supports both USB and PS/2 keyboards, and the UART connection can operate at both 3.3V and 5V allowing you to connect it to pretty much any modern single board computer or microcontroller—from the Raspberry Pi, to the BeagleBone, or even an Arduino.

The anatomy of the diy-VT100. (📷: Mad Resistor)

Both the hardware design and the firmware are open source and are released under a GNU GPLv3 license. You can learn more about the project on its Hackster.io page, and will soon be able to pick one up on Crowd Supply.

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