http://www.nondot.org/sabre/os/articles
The Operating System Resource Center has plenty of technical informations about both hardware specs (8259, 8042, ATA bus, etc) and software conventions (BIOS bootstrap format, etc).
Software
| The Boot Process |
|
|---|---|
| Partitions |
|
| File Systems |
|
| Memory Management |
|
| Protected Mode |
|
| Executable File Formats |
|
| Plug'n'Play Specs |
|
| Device Driver Interfaces |
|
| Miscellaneous Software |
|
Hardware
| Processor Architecture |
|
|---|---|
| Interconnect Buses |
|
| Disk and Disc Drives |
|
| Human Interface Devices |
|
| Sound Devices |
|
| Communication Devices |
|
| Networking Devices |
|
| Miscellaneous Devices |
|
| Other Hardware |
|