Robert Kahle's 2007 post was all I needed to hack the adapter. Using an
8 pin microchip 10f220, I wrote the following code. It's the .HEX If
you want the source PM me.

:020000040000FA
:0800080005281F28A300A40035
:100010000830A2002508A306A30C2508A300031C92
:1000200013281830A306A30C2308A5002408A30056
:100030000310A30C2308A400A20B0A280800A501A2
:10004000F0300620103006200000003006200000AE
:084000000100020003000400AE
:02400E00F93F78
:00000001FF

The code aint pretty, but it works.

This sends a fake 90W signal to the mobo to make it think a dell adapter
is connected. I needed it because I'm off grid and I only have 24VDC.
I step this down t 18V and use the PIC to fool the mobo. Been good for
9 months now.

You'll need an old plug to connect to the laptop and you'll need to
identify +, - and signal (centre) pin.
Connect 18V into the laptop. The centre pin of the goes to pin 3 of the
PIC.
Put a ge diode anode on pin 3, cathode k on pin 2.
Put 0v on pin 7. 330n cap pin 2 to pin 7. You get about 2.5V on pin 2,
which is just enough to power the PIC. The PIC waits about 200ms and
then sends the message when requested by the mobo. There is so little
current sent by the mobo that you can barely light a LED, so only use a
DVM and dont connect anything else!

I've tested it on 2 d610 and 1 d600. Flawless!

You'll need a good grasp of electronics to make sense of this, not to
mention programming PICs. I'm not selling these and dont intend to.

Usual disclaimers apply.