Robbert Haarman



One of the great things about the Internet is the vast amount of tutorials and HOWTOs it harbors. In the spirit of Free1 sharing of information, I provide some of my own knowledge in the tutorials hosted here.

CCD Mirroring HOWTO

This HOWTO describes how to set up partition mirroring on OpenBSD, using the concatenated disk driver, ccd(4). This is like RAID Level 1, but does not require special hardware or recompiling the kernel, and it works on individual partitions, not just on whole disks.

Installing Mac OS

This document describes how I installed System 7.5.3 on an old Powermac 6100. It can be used as a tutorial for installing Mac OS on Macintoshes that don't have a working operating system with Stuffit Expander installed.

Linux File System Drivers

As part of the netfs project, I wanted to write a filesystem driver for Linux, so that files shared through netfs could be accessed like any other file. However, I had a hard time finding good documentation, and did not find a good overview of what functions need to be provided and how, nor a good step by step guide. That step by step guide is what I intend to provide here.


Scheme is an elegant LISP dialect with a clean syntax. The language is easy to learn, yet very flexible and powerful. One noteworthy property of Scheme is that it supports tail call elimination, which allows the execution of many recursive algorithms in constant space.

x86 OS Development

I have always been fascinated by low-level programming. I enjoy starting at a very basic level and making the system work from there. In other words, I like to write operating systems! This is a tutorial for others who would like to experiment with writing their own operating system, but don't know where to start.

1 ‘Free’ as in ‘freedom’