I thought that I would finally add some content to this blog, so here are two ATTINY2313 based multiplexing Nixie clock designs. Source code, compiled hexfiles, and schematics are included in the zip (along with readme).
Brief summary: Mike Moorrees’ MC34063 MK1.5 high-voltage supply is used to drive the nixies. The nixies are multiplexed via MPSA42 & MPSA92 high-voltage transistors. The ATTINY2313 drives a single 74141 nixie driver IC, which is bussed to the entire array of nixie tubes. Additionally, a piezo alarm is added, as well as an AM/PM indicator, and an Alarm ON/OFF indicator (for the 4-digit version). This code is pretty tight. I think that to add more functonality (such as leading digit blanking, or optional 24hour clock mode) would really require a larger microcontroller at this point. You can find these at: