Parent Category: How-to's Category: DEC hardware errors, and how to repair them Written by Administrator

PDP-11/34 stops at UNIBUS timeout at random intervalls

Error: while booting XXDP, or other OSses, the PDP-11 stops at certain addresses. Stopping seems a bit random like, but the addresses are from a small pool.

Explanation: the serial console interface DL11-W M7856 was a little bad, and damaged the UNIBUS signals.

This can occur with any card, and at any time!

Repair: reduce the system to one UNIBUS backplane with Serial and RAM, and replace all remaining boards with known good ones.

Contact: Jörg Hoppe, Thomas Höffken