Re-using ADM3A with Raspberry Pi

ADM3A is a dumb terminal with discreet logic chips and no major integrated circuits. In this post, an anonymous blogger has made an attempt to put this terminal online to snag a picture of it on retro.hackaday.com but unfortunately, it didn’t work out. After sneaking parsley to the parts of this device, he discovered that a big clunking mechanical power switch has failed to work. The 37-year-old electronics switch had gotten dirty and corroded, therefore, he cleaned it out and luckily, now it is working again.

He made a MAX232 serial adapter for a raspberry pi and then hooked the Pi up to the terminal. The adopted serial adapter here is just a typical MAX232 circuit and one can purchase them online. After figuring out that the header for the pi can be put right on the board to replace the headache of making an adapter cable, he concentrated to hook up the tx and rx lines. Then, he skipped DTR and CTR and used a standard serial port header for the serial connection. This enabled him to comfortably swap between 25 pin serial and 9 pin serial.

In the software section, the Pi is running Wheezy. It is a serial terminal that runs at a maximum speed of 19200 baud. Further, the Pi is already equipped with many configurations that can use a serial terminal at 115200 baud. Finally, with some adjustments and a reboot, the pi will print its console correctly to the terminal.

In further observation, it was found that some programs were not compatible with the terminal and hence don’t run easily. Further, various adjustments and modifications are required in color section where anyone who tries to color, all of its control characters are displayed on the screen. And also don’t go with lynx, as it is unusable without the correct terminal definition.