Yeah very early on Apple referred to sliders as “dials” but it never really stuck. Where did you see that last paragraph you quoted? I don’t see it in my copy of Inside Macintosh. Anyway it’s wrong - the only “dial” defined in ROM is the standard-issue scroll bar, I promise.
Unfortunately, I only have a multimeter to check these lines at the moment.
I'll have to double-check the CPU-GLU address lines tomorrow to confirm that everything is working correctly, but no problems were detected on my first pass today.
I just picked up a non-working 128k as a project. When I turn it on there is no chime or video, but there is a repeating clicking sound coming from the speaker. I'd say about 2 clicks per second. I'm assuming it's an analog board issue, but I don't know where to start looking. None of the capacitors are swollen that I can see with a quick look from above, I haven't pulled the analog board out yet to take a closer look. A reddit user said it could be a HV diode, I haven't taken a look at that yet to see if it is visibly damaged, I'll be doing that tomorrow. If anyone has ideas for trouble
I'm thinking this as well. Looks like only half of the VRAM is available to the main bus, but all of it is being displayed. A stuck VADR line into the muxes can result in portions of the display repeating, but that's not what you have here. I'd look closely at the lower A lines.
Are you checking these with a scope or DMM? A continuity test won't tell you about a short to GND, etc.