Bill, I am assuming you have done all the usual after a physical move of the system - reseated all the boards and whatever we called those green blocks on top of the board pairs, and cables - both ends. If not, that might be the hint the system is giving you.
That is about all I can think of something more than 40 years since I trouble shot an /e/ bob On Sun, Dec 15, 2019 at 12:10 PM Bill Degnan via cctech <cct...@classiccmp.org> wrote: > > Hi - I am looking for some help. > > I have had a PDP 8e with RK05 drives that has run pretty reliably for many > years, but after moving it a strange symptom has come up, preventing it > from operating correctly. I am hoping someone can advise. > > Here is an example > > 1. Power up drives and PDP 8e > 2. Load OS/8 > 3. Load ADVENT > 4. Program loads, asks if I want instructions. I can enter Y or N and the > system responds. The familiar scrolling light pattern appears on the front > panel to indicate awaiting input > 5. As soon as I attempt an action such as "S" (with no quotes) the front > panel freezes and I have to CTRL+C to exit ADVENT, dumping me to the dot > prompt. > > Similar issue when running the MUSIC.SV program. I can load the program and > get up to the point of entering a song, but when I enter a song name the > system freezes on the first note. > > BASIC works fine however. Which tells me that I have a CPU problem, not a > RAM problem but this is just my hunch. > > Any ideas how to diagnose this? Running MAINDEC programs is always > frustrating. I am attempting to load the main DECX8 SYSTEM EXERCISER to see > if there are any clues from this as to the cause of the freezing system. > . > https://www.pdp8online.com/os/os8/os8_cmd.shtml#DECX8 > > Thanks > > Bill
