Michael Doornbos

OffGlobe LLC

My company. Service-disabled veteran-owned (SDVOSB). Building products at the intersection of security, accessibility, and independent technology.

Assistive Technology

Spatial audio, real-time object detection, and head-tracked 3D sound for blind and visually impaired users. Working prototype built, pilot study in planning.

Also building one-off devices for users with special needs. Buttons, switches, sensors, and interfaces shaped around what a specific person actually needs, not a one-size-fits-all product. Some of this is hardware. Some is firmware on small microcontrollers. All of it is the kind of thing that doesn’t exist on a store shelf.

HP-16C Calculator (iOS)

A faithful recreation of the HP-16C programmer’s calculator for iPhone. RPN, base conversions, bit manipulation, all the original functions plus a second display line for the Y register and full 32-bit binary without scrolling. 200+ unit tests. Free on the App Store.

LoreKeeper

Helping families capture and preserve their stories before they’re lost. Voice capture, guided prompts, photo-prompted memories, and printed story books.

Writing

I write across three sites:

Fiction

Three completed novels. The most recent finished in March 2026.

OT Security

Built an OT/IT security practice from scratch at Assurance Data, Inc., deployed across 100+ solar facilities. SCADA, Modbus, zero-trust architecture.

Apollo Guidance Computer

Block II AGC emulator written from scratch in Python. Reference implementation with a Textual TUI, ASCII DSKY, rope loader, real-time register and memory visualization, single-step and breakpoints, live disassembly, closed-loop lunar lander dynamics. Seven years in. A learning project. Not released.

CROSSWOZ

A cross-CPU emulator in the spirit of Grant Searle’s Multicomp and the Cerberus 2080. One shared 64K memory bus, one WOZMON-style monitor, swap the CPU underneath. Eight cores written from scratch: 6502, 65C02, Z80, 8080, 8085, 6809, 1802, TMS9900. Mini-assembler per CPU, paper-tape I/O, full Textual TUI. MiSTer FPGA core and a discrete PCB are planned.

Electronics and PCB Design

KiCad schematic capture and board layout. The biggest one is VICsRevenge, an FPGA-based drop-in replacement for the MOS 6560-1 VIC chip — resistor-ladder color palette, composite video synthesis, the whole thing. Plenty of smaller boards along the way: video mods, paper-tape readers and punches, adapter boards, and breakout PCBs for the vintage machines I keep alive.

Hardware

Vintage computer restoration, circuit board design, and the occasional LFSR shadow box. HAM radio operator (N4LNX).

Past Work