DIY VT100 terminal
In August 1978, Digital Equipment Corporation (DEC) introduced the VT100 video terminal and was one of the first terminals to provide ANSI escape codes for cursor control and other tasks. DEC itself added some more elaborate codes for special functions and soon the (ANSI standard) became the standard for video terminals in the form of the VT100 terminal. The VT100 series was replaced by the VT200 series by DEC from 1983, which offers an even more extensive control code set and which also became a great success. The VT100 terminal was a logical successor to the VT52 that came out in 1975 and which text display of 80 columns and 24 rows. Other improvements of the VT100 over the VT52 included a 132 column mode and the ability for flashing, bold, inverse, and underlined letters on the screen. Also, the VT100 had some character patterns in the ROM to do very limited graphics. The terminals were connected via a cheap serial cable which also contributed to their popularity.
In my first job as a programmer I worked with a Zilog development system, which was actually a large CP/M machine, on which a serial (RS232) cable was connected to a VT100 terminal. In the morning first boot with an 8 inch CP/M disk, then put the data disk in and I could write my programs, compile and link and then test. Later when modems and BBS systems became popular, the VT100 / ANSI terminals resurfaced, but this time in emulation programs on the various home computers. At that time I wrote the MightCom communication program myself for my then employer Micro Technology which also contained a number of different terminal emulations, including of course VT100. Later when I started working with DEC systems I also have this emulator made it right down to the last detail so that I could use it on the VAX 11-750.
When dealing with retro computers, a good VT100 terminal is quite important. Many old computer systems, but also the newer ones like the single board computers sold as kit still use a VT100 terminal as input/output. Now it is quite possible to do this with a terminal emulation on a PC or laptop, but I found this a bit cumbersome. And it didn't feel quite real, I felt like I was working on a modern computer. That's why I took an old VGA monitor (who doesn't have one from old times, or you can buy one at thrift stores for ten euros) and a small VT100 card I soldered together myself. This is now in my workshop with the retro and SBC systems and when I want to use one is this only takes the rewiring of a serial cable. I use a standard USB keyboard with a PS/2 adapter and always have a complete VT100 terminal at my disposal. I use this for my Z80-MBC2 CP/M board and my Appla-1 replica board
DIY VT100 terminal
There are several kits of simple VT100 terminals on the market, often based on a PIC microcontroller. The problem is often to buy a complete the kit or to buy the PCB separately. I'm not going to start building the terminal on a PCB experiment board. I have no stock or any relationship with this company but order regularly and they have a nice and complete DIY kit for a VT100 terminal, for a reasonable price and delivered from the Netherlands. The package consists of easy components (no SMD luckily) and is easy to assemble. It has a VGA output in a composite video output and a PS/2 keyboard input. The whole can be powered via a USB connection and the print also has a 5 Volt pin to supply voltage to, for example, a singleboard computer can be powered by the terminal board. So you can turn everything on with one switch. The terminal supports both VT100 and VT52. The serial input is both TTL and RS232, baud rates are adjustable from 40 to 1,000,000 bits per second with odd, even or no parity and one or two stop bits. The terminal can be configured via an extensive menu and has three built-in fonts. This is the terminal I use myself and which is installed next to an old VGA monitor.
Last update: 21-05-2022