The "Time Machines"

From the 4000-series to Embedded Systems

It all started when I got a photocopy of a Motorola 4000-series data book from my mentor in high school. My first electronics project was building a digital clock, pictured below (the big transparent box):

With the soldering practice gained building the first one, a "desktop" version was made (the small black one on top). Even the size of clocks follows Moore's Law.


As soon as I learned about microcontrollers, I made a clock with an AT89C2051 using assembly language.

The chip was obsolete even back then, but it was everywhere in the stores I frequented. They supply repair parts for industrial equipment and household appliances.

Update 2013

The clock I built in 2006 has been running on my wall for over six years now. Recently I noticed some LEDs on the segment display do not fully turn off.

I can no longer buy replacement for the microcontroller, and Windows 7 has no driver for my parallel programmer for the chip. So I rebuilt the circuit for an Attiny2313 and rewrote the program in C. Here's a video of it under test:

It has followed me from Macau to Toronto to Los Angeles to Honolulu and is still running on my wall as of 2022 (hello COVID19).