UNIX Fourth Edition
UNIX Fourth Edition (often referred to as UNIX V4 or V4 UNIX - 'Unix' was still normally given in all capital letters at this point in time) was an important early version of UNIX. It was the first version in which the kernel was written in C. It also had minor changes to the UNIX file system (such as the ability of any inode to hold a device 'special file'), which left it in the form it retained until the BSD Fast File System.
Apparently, the only model of PDP-11 supported was the PDP-11/45.
A complete copy of Fourth Edition does not seem to be extant. TUHS has a copy of the 'UNIX Programmer's Manual' and the source for what would become the V4 kernel. The main differences in this 'nsys' kernel compared to the later V4 kernel are the earlier V3 way of registering signal handlers, and a few not yet implemented system calls. Most importantly pipes had not yet been implemented, making this kernel not fully functional even on a V3 system.
- nsys - complete kernel source
- UNIX Programmer's Manual Fourth Edition - Introduction
- File system
- UNIX Programmer's Manual: Fourth Edition
|v • d • e UNIX Versions, Vendors and Related
| Research Unix PDP-7 UNIX • UNIX First Edition • UNIX Second Edition • UNIX Third Edition
UNIX Fourth Edition • UNIX Fifth Edition • UNIX Sixth Edition • Unix Seventh Edition
Unix Eighth Edition • Unix Ninth Edition • Unix Tenth Edition
LSX • MINI-UNIX • Unix/32V