A Hazeltine 1420 Lives Again

The Hazeltine 1420, a well-known brand capable of emulating other terminals, was brought back to life by The Byte Attic. The device had been sitting unused for a long time, and the team finally got around to restoring it.

The restoration process revealed a number of issues. The old terminal was full of suspect capacitors, and a power transistor was missing, indicating that someone had previously stripped the unit to fix another.

The team's plan was to improve the device by replacing the old, heat-generating linear regulators with modern switching regulators. This was a common issue with these types of devices, and scorch marks under the bridge rectifiers were a common sign of the problem.

Another major concern was the unobtainable chips that held the character sets and other logic. If these chips were dead, there would be virtually no way to replace them. The team's plan was to read them, if possible, and design replacements for the day they did fail.

The restoration was a long process, and the team documented several early decisions that came back to bite them later. The ROMs did work, but because they are so prone to failure and so hard to replace, they went into storage and were replaced with an adapter using modern components.