Hi, this site is both a living notebook and a place to share my projects. These projects include computers built from scratch out of TTL logic chips, earlier machines built around the RCA 1802, other builds, the tools and techniques I use to make things, and the reading list I keep for entrepreneurship and product development.
An 8-bit computer built from 74-series TTL chips on a backplane of cards, run entirely by microcode, with a monitor, BASIC, a disk operating system and a C compiler.
Project site · The cards · Posts · Source
A hand-built 8-bit microcoded CPU: TTL cards designed in KiCad, and the same machine running on an FPGA with a graphics engine, its own operating system, BASIC and C compilers.
Project site · Source
Computers and cards built around the RCA COSMAC 1802 (2011–2014): systems running ELF/OS, memory, video, IDE and front-panel cards, and the bus that ties them together.
Project page
1802 projects designed by others: the MicroELF, ELF2K and EELF boards I built, with more to come.
Project page
The Heathkit ET-3400 Microcomputer Learning System, a Motorola 6800 trainer, with its ETA-3400 accessory, here running BASIC on a video terminal.
Project page
Projects with the DEC PDP‑8. Write-up coming soon.
Project page
A clock that shows the hours, minutes and seconds on three analog panel meters.
The clock story
Builds that don’t fit anywhere else, such as an Altairduino, an Altair 8800 replica.
Altairduino · All posts
How I make things, starting with milling circuit boards on an Othermill.
Othermill notes
