Continuing the debugging of my recently acquired PDP-8/E, I wrote an address test that's easy to enter from the front panel: --- # PDP8 Quick Address Test # Pass 1: Loads locations 23-7777 with their own address. # Pass 2: Tests each location for the correct address. If # it fails (address does not equal it's own address) then # the diagnostic halts with the error location in 22. # The contents of that location displays the error. # By Lyle Bickley # 0000 7600 CLA 0001 1021 TAD 21 0002 3022 DCA 22 0003 1022 TAD 22 0004 3422 DCA I 22 0005 2022 ISZ 22 0006 5003 JMP 3 0007 1021 TAD 21 0010 3022 DCA 22 0011 1022 TAD 22 0012 7041 CMA IAC 0013 1422 TAD I 22 0014 7440 SZA 0015 7402 HLT (ERROR!) 0016 2022 ISZ 22 0017 5011 JMP 11 0020 5000 JMP 0 (START OVER) 0021 0023 0022 0000 --- Cheers, Lyle -- 73 NM6Y Bickley Consulting West https://bickleywest.com "Black holes are where God is dividing by zero"