Unix V6 on the RL02

Sixth Edition Unix (1975), Tim Shoppa's rescued RL02 pack, booting straight from DL0. The smallest real Unix — kernel, C compiler and the classic userland on one ten-megabyte cartridge.

Bus	QBUS · QBone
Needs	Any Q-bus PDP-11 with memory management — 11/23 upward — and 256 KB of memory. The line clock (BEVNT) must tick, or time stands still.
Guest	Unix V6
Cards	RLV12 · RL02
Download	3 MB
Added	2026-08-31
Maintainer	QUniLator project — contact

Why it exists

The Unix that Lions annotated: a complete timesharing system small enough to read. This pack carries the source tree, so the system on the screen and the code in /usr/src are the same thing.

Using it

• Switch the machine on and boot DL0 from the bootstrap prompt.
• At the '!' prompt type: unix
• The system comes up as a root shell. The console is upper-case until you say so - the first command is 'STTY -LCASE'.
• Type 'sync' twice before switching off; V6 has no shutdown command.

Known problems

• The clock needs the line-time interrupt; without BEVNT on the bus, 'date' stands still.
• This build was modified to run without an FPP; '!unix-fpp' boots Shoppa's original floating-point kernel instead.

Links

• Tim Shoppa's V6 rescue at TUHS, the source of this pack
• The Caldera license covering V1-V7 and 32V

Getting it onto a board

The board imports this itself once it subscribes to the catalogue — it fetches, verifies the checksum and imports, which is the route to prefer for a bundle this size.

To download it by hand and use the import dialog instead:

• unixv6.qcfg.zip — 3 MB

sha256 690cb84e5cd629aacf09624206304fa6773feaccc457117b668d17bb2ad0513d