Nice progress - but 2 peculiarities / queries

[Charles Ess]

I've gotten my S/N 248 started (thanks again, José, Oscar & Co: terrific kit in so many ways) - to the point that I could run the test program for the lights and switches.

(Running trixie on a Pi5. I've used the Pi5 for months to run the virtual panel, etc., as well as to shunt the P7 display over to an Elecrow 7" display - eventually destined for the rack version: I had major fits when the OS upgrade came, but those were sorted out some time ago, so far as I can tell.)

All the lights work as they should, but I have one dead switch on the bottom row of the main panel.(taped in blue in the image below): signalled by a "2" in the series of numbers for the switches that doesn't change, no matter what. The toggle itself feels unusually loose: I very likely killed it when soldering. Having made plenty of mistakes with previous builds, I optimistic that I can desolder and then resolder in a replacement: a pain but not a major one (I hope).

The lower panel switches also work - not as expected from the building instructions (push up) but exactly as described by sunnyboy010101 in a recent post (thanks for that: no small relief!). 

I can also load and then run a program (e.g., snowflake) using the sense switches to set the boot number,  then the read in switch to read the paper tape, and then the start switch to get the program going. But ...

Peculiarities / queries:

1) Unlike when running the program in virtual mode, the program stops after ca. 5 seconds (as do the other one or two I tested). Oddly, without having toggled on the Sing. step switch, pressing the Start switch increments the program one step (if I'm reading the lights properly) as does the Cont switch. But the display has died, FWIW. Perhaps just a configuration issue - or perhaps an odd artifact of the dead switch - or?

2) when booting up the Pi, but before starting the pdp1 - and after stopping it - several of the LEDs on the 2nd row are lit up:

Is this more or less normal - e.g., similar to the dim lights that would show up on the PiDP-10 early on? Or is this also, e.g., an artifact of the bad switch (taped in blue, bottom) - or something else?  
As always, many thanks in advance for any help or advice.

- charles

[Charles Ess]

Answering my own questions ...
A replacement switch passed the switch test (whew!) - and now running, e.g., the snowflake program proceeds as expected.  So far, so good.
I still have the odd set of lights on the 2nd row (Extension / Memory Address) - but that seems harmless?
Many thanks for any further tips, tricks, etc.

- charles

[Jeremy Radwan]

For the LEDs on at boot, see here:  Power up LED row. But running the test program those LEDs go out and the test program runs fine. I didnt expect this. Any ideas?

[Charles Ess]

Perfect - thanks!