Struggling to get my 'new' Apple Lisa 2/10 to boot from an external ESProfile

[Huxley]

Hi all!

My wife and I visited VCF West a few months ago, and came home with a lovely Apple Lisa 2/10. The machine is in good shape overall, including a functional internal 10MB Widget drive with MacWorks XL installed. The only real issue with the machine that I'm aware of is that the upper Parallel port doesn't work properly (according to the previous owner).

I also bought an ESProfile (external hard drive emulator), which I have attached to the lower Parallel port. However, when I power on the Lisa and get to the boot select menu, pressing Apple-4 to select the lower Parallel port (where the ESProfile is attached) causes the ESProfile to blink twice, and then the Lisa emits three loud beeps and asks if I want to try again or just restart.

I've done the following troubleshooting steps:

• Made sure the ESProfile is getting good power via a known-good Micro USB cable and known good wall charger
• Tested the ESProfile on both the upper and lower Parallel ports (same behavior either way)
• Flashed / updated the firmware on the ESP32 module according to the steps on the GitHub page
• Tried with a wide variety of bootable Lisa image files, each placed in the root of the microSD card and renamed "profile.image"
• Downloaded and tried to use the "Selector" bootable image
• Reformatted the microSD card and reinstalled various bootable images, each renamed "profile.image"
• Moved the Parallel card from Slot 1 to Slot 2 (no change in behavior, other than the boot device numbers changing appropriately in the boot selection menu)

What am I missing here? Any suggestions would be much appreciated! Maybe @AlexTheCat123 might have an idea?

 

[Huxley]

Update:

I'd already been tinkering with it for hours by the time I posted and my brain was turning into mush... so I kept going for another 2-3 hours. Here are some more details and updates:

• I get the same response whether I use the keyboard shortcut or manually click the icon for the lower Parallel port
• The screen shows an icon of a ProFile drive with an X through it and the code "85" below
  • From what I can tell after poking around in some old Lisa docs, error code 85 seems to indicate that the external drive "can't keep up" - what does that mean in this context?
• I also installed everything onto a different known-good microSD card but got the same results
• I did a complete low-level (aka not "quick") format on both microSD cards and reinstalled the boot images, no change in results
• I'm not actually sure if my external-style ESProfile will work internally or not. The Parallel cable is detachable and it looks like the same type of cable that connects the internal Widget drive to the system, but I've read at least one other thread from someone who destroyed their ESProfile and badly damaged their Lisa by getting the un-keyed internal cable plugged in correctly, so I'm a bit nervous to try that option...
• Early in the evening, I shot a short video of what I'm getting when I try to boot from the ESProfile (including the beeps):
• I signed up for the LisaList2 last night, still waiting for an acceptance email

Grateful for any tips or suggestions!