LisaList2

That could be interesting! I'm sure there's a way to do it with enough ingenuity, even if it's not immediately obvious.

Quote from: berskyboy on September 19, 2026, 03:04:53 PM

Quote from: sigma7 on September 19, 2026, 02:57:02 PMTest CR18 on the component side (one end still disconnected from the board) in both directions using the diode test mode.

CR18 in diode mode
OL, OL

Did you see the edit I made that says "Note the manual says on page 17 that to enter Diode Test mode, you have to press the "Func" button after rotating the switch to the diode test/continuity position. When in that mode, the diode symbol will be shown in the display."?

If not, try the test again in diode test mode.

Hmm, that's quite a restriction! I guess one workaround might be to try and write a device driver for a kind of virtual disk. A program could make a new file appear on a volume that gets mounted, and then you can copy the file onto a real drive.

Quote from: sigma7 on September 19, 2026, 02:57:02 PMTest CR18 on the component side (one end still disconnected from the board) in both directions using the diode test mode.

CR18 in diode mode
OL, OL

CR18 in resistance ohm mode
33.4, 0.45

Quote from: berskyboy on September 19, 2026, 02:52:45 PMHere's a photo of it. ASTrOAI CM2KOR
https://www.dropbox.com/scl/fi/2giwzufwhe0l051stcxix/ASTrOAI.HEIC?rlkey=b7got1wh776cwtdchmoxarybb&st=i8ld7461&dl=0

that was in diode mode.

Test CR18 on the component side (one end still disconnected from the board) in both directions using the diode test mode.

Note the manual says on page 17 that to enter Diode Test mode, you have to press the "Func" button after rotating the switch to the diode test/continuity position. When in that mode, the diode symbol will be shown in the display.

Quote from: sigma7 on September 19, 2026, 01:33:42 PMAre those measurements using a "diode test" function? From the readings I'd guess it was a resistance mode.

So I can peruse the manual, what is the brand and model of DMM you are using now?

Here's a photo of it. ASTrOAI CM2KOR
https://www.dropbox.com/scl/fi/2giwzufwhe0l051stcxix/ASTrOAI.HEIC?rlkey=b7got1wh776cwtdchmoxarybb&st=i8ld7461&dl=0

that was in diode mode.

Yeah, I believe the Desktop Manager is the only thing that can do this under stock LOS. I'm sure you could write a program that runs under LOS and modifies the catalog file in real-time to make things appear and disappear, but that's not a bare LOS install anymore. And that may not even work anyway if the Desktop Manager keeps the catalog open at all times (preventing our program from opening it) instead of only opening it when necessary.

Quote from: stepleton on September 19, 2026, 07:19:27 AMIf I make a Lisa program, I want to run into those frictions that come from 40 years of divergent history and not being on the same wavelength. I want to try to get into its designers' heads. I want to have those moments of "so that's why it's this way". I think this kind of understanding is really helpful to trying to make something that would be a convincing "what if" Lisa program from, say, 1985. Could I do this kind of exploration by using AI to code? I actually think I could! But I'd have to be pretty careful to rein in the AI and keep it patient and "true" to the feel of the experience, and to allow me to discover along with it. AI coding agents are not made for patience --- they are built to go relentlessly and just get it done, no matter what "it" is. So you need to do work if you want to ride along with them on the scenic route.

I generally agree with this sentiment. It can be fun to mess around with AI to make Lisa programs just to see what it's capable of, but I much prefer actually writing the stuff myself and keeping it true to the history of the original machine if it's something that I actually care about. I'm not trying to take anything away from the AI-generated apps that are out there right now when I say this; it's just my personal preference for the stuff that I actually produce myself.

Quote from: berskyboy on September 19, 2026, 12:04:22 PM

Quote from: sigma7 on September 19, 2026, 05:20:40 AMExcellent; to see how it behaves compared to the other one, try these measurements again using the diode test mode:

I stopped because should I put Q1 and Q2 back into the PSU?

No, make these measurements with Q1 and Q2 removed, but that is a good question.

QuoteDiodes  Fwd, Rev            Description      Measurement
{BA, BB}  0.13, inf  CR20a, CR20b      BA: 0, OL BB: 0,OL
{DA, DB}  0.30, 0.37  CR25, CR23        DA: OL,OL DB:

And for each of Q1 and Q2 now out of circuit, also measure
Q1
Red to Black         
Lead 1 to Lead 2.      0       
Lead 2 to Lead 1        0.1

Q2
Red to Black         
Lead 1 to Lead 2        0.8
Lead 2 to Lead 1        0.6

Are those measurements using a "diode test" function? From the readings I'd guess it was a resistance mode.

So I can peruse the manual, what is the brand and model of DMM you are using now?

Quote from: sigma7 on September 19, 2026, 05:20:40 AMExcellent; to see how it behaves compared to the other one, try these measurements again using the diode test mode:

Diodes   Fwd, Rev            Description       Measurement
{BA, BB}   0.13, inf   CR20a, CR20b      BA: 0, OL BB: 0,OL
{DA, DB}   0.30, 0.37   CR25, CR23        DA: OL,OL DB:
.
I stopped because should I put Q1 and Q2 back into the PSU?

And for each of Q1 and Q2 now out of circuit, also measure

Q1
Red to Black         
Lead 1 to Lead 2.       0       
Lead 2 to Lead 1        0.1

Q2
Red to Black         
Lead 1 to Lead 2        0.8
Lead 2 to Lead 1        0.6