Well, the boards had a pretty glaring error when they came in: My MAX232 chips are DIP-16, and I had defined a DIP-14 package. (KiCAD & gerbers in project source have been fixed)

I thought that KiCAD would raise a warning for this, it turns out that's not the case! Serves me right for relying on automated checks instead of checking carefully myself. Anyway, as part of this I had searched Google for 'MAX232 DIP-14 variant', because I thought that perhaps I had designed with some other chip by accident, and could just order it.

No such luck! Google's AI spewed out something to the effect that no such variant exists, and moreover it's impossible because (blah blah blah). Well, it underestimates what I spiteful miser I am (15$ for new boards? Bah, humbug.). So we should go ahead and prove it wrong.

Pins 8 & 9, which don't fit in my board, are for R2IN and R2OUT, which I don't use. Optimally, one of those should be grounded, but I could live without that. So logically, I could just cut two pins off the IC. Then it would be all lopsided though, can't have that!

The MAX232 isn't a particularly complex chip, so I reasoned even on old fab processes, the silicon die would be pretty small. It would be also very likely be positioned optimally within the chip package to save on (probably gold) bonding wire. So I could just... cut off the rest of the chip.

Then pins 1-7 on the new chip would already be connected correctly, and pins 8-14 would need to be offset by 2 positions by cutting any connections & making new ones with bodge wires.

That leaves the following sequence of operations for me to follow on the new chip:

• Pin 8: No change required
• Pin 9: Bodge wire to pin 1 of ESP32S3
• Pin 10: Cut connection to GND around pin, then bodge wire to pin 2 of ESP32S3
• Pin 11: Cut connection to trace, bodge wire to serial port pin 3
• Pin 12: Cut connection to trace, bodge wire to serial port pin 2
• Pin 13: Cut connection to trace, bodge wire to GND
• Pin 14: Cut connection to trace, bodge wire to VCC

This took about 20 minutes of surgery, I checked connections, powered it on, and it was fine. Before and after surgery image below for your possible amusement and edification. Pins 11,12,13 connected on verso.