The Newclock-80 was a clock/calendar add-on for the TRS‑80 released by Alpha Products in 1983. It replaced their TIMEDATE 80 clock/calendar but remained software compatible with it.
The Newclock-80 plugged into the expansion bus and required no hardware modifications. The price was $59.95 for both the Model I and Model III versions, a significant reduction from the $95 price of the TIMEDATE 80. The Model III version also worked on the Model 4. In 1985, the price of the Model I version was reduced to $39.95.
The Newclock-80 preserved the date and time, even when the computer was off. It featured a MSM5832 clock chip with a lithium battery backup which was said to last for two years. That battery, a CR2032, can still be purchased today. As an Alpha Products advertisement stated:
Wouldn’t it be nice if your computer could always boot up with the right time and date and then stay accurate? Newclock-80 will enhance your Model I or III systems with powerful clock/calendar/timer functions.
Both Model I TRSDOS Disk BASIC and Model III cassette BASIC contained a TIME$ command which displayed the time and date. But without a clock/calendar, that time tended to drift during disk access and it was lost whenever the computer was shut off.
The Newclock-80 boasted compatibility with all major TRS‑80 operating systems. It came with a program that could set the clock and another that patched the BASIC TIME$ command to read the Newclock-80. Third-party programmers also wrote programs and patches which supported the Newclock-80.