After reading what Robert Kahle had found I was inspired to write my own code to read the chip in dell power supplies. I happen to have a few power supplies so I read them all and came up with the following data:

Summery of strings from my power supplies:
MFG- ?? PS -W- -V- -A- --------SerialNumber-------- CRC-16
DELL 00 AC 150 195 077 CN-0J408P-48661-228-1U2D-A02 0x9447
DELL 00 AC 090 195 046 CN-0J62H3-71615-04N-49C3-A01 0xA76D
..... 00 AC 090 195 046 CN-0C2894-48661-475-6PD3-A02 0xD533
DELL 00 AC 090 195 046 CN-09T215-71615-41U-3355-L03 0x2564
DELL 00 AC 065 195 033 CN-05U092-71615-464-0220-A03 0xEF29
DELL 00 AC 065 195 033 CN-0F7970-71615-55G-02AB-A00 0x7DAB

Robert had it all right except for the last two digits which I have verified are a CRC16 of the previous 40 bytes.
Notes: The top supply above is 150 watts proving Robert right about the three digits. The third line is very interesting as the first four digits are nulls instead of "DELL". The CRC16 is either not valid or calculated different. But my laptops don't care!

Full read of device summarized on line 1 (150 Watt,DS2502 chip)
ROM data bytes a Family[1], Address[6], and CRC[1]
09 1A 3A 0B 38 00 00 0E CRC is valid.
Chip = DS2502, 1024b Add-Only Memory
EPROM Status bytes a
FF FF FF FF FF FF FF 00 CRC:9C is valid.
EPROM Data is:
0000: 44 45 4C 4C 30 30 41 43 31 35 30 31 39 35 30 37
D E L L 0 0 A C 1 5 0 1 9 5 0 7
0010: 37 43 4E 30 4A 34 30 38 50 34 38 36 36 31 32 32
7 C N 0 J 4 0 8 P 4 8 6 6 1 2 2
0020: 38 31 55 32 44 41 30 32 47 94 FF FF FF FF FF FF
8 1 U 2 D A 0 2 G . . . . . . .
0030: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
. . . . . . . . . . . . . . . .
0040: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
. . . . . . . . . . . . . . . .
0050: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
. . . . . . . . . . . . . . . .
0060: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
. . . . . . . . . . . . . . . .
0070: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
. . . . . . . . . . . . . . . .
Entire EEPROM CRC: 1B is valid.
Calculated CRC16: 9447 on first 40 bytes of EPROM is a match.

Full read of device summarized on line 3. 90 Watt, old DS2501 chip, ** invalid 16bit CRC **, first 4 bytes do not say "DELL"!:
ROM data bytes a Family[1], Address[6], and CRC[1]
11 54 DB 98 00 00 00 E7 CRC is valid.
Chip = DS2501, 512b Add-Only Memory
EPROM Status bytes a
F3 FF FF FF FF FF FF 00 CRC:9C is valid.
EPROM Data is:
0000: 00 00 00 00 30 30 41 43 30 39 30 31 39 35 30 34
. . . . 0 0 A C 0 9 0 1 9 5 0 4
0010: 36 43 4E 30 43 32 38 39 34 34 38 36 36 31 34 37
6 C N 0 C 2 8 9 4 4 8 6 6 1 4 7
0020: 35 36 50 44 33 41 30 32 33 D5 FF FF FF FF FF FF
5 6 P D 3 A 0 2 3 . . . . . . .
0030: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
. . . . . . . . . . . . . . . .
Invalid EPROM data CRC: FF Calculated CRC:57
Calculated CRC16: F3E4 on first 40 bytes of EPROM is NOT a match!

Hope this helps you.
I wrote the reader program for an arduino so it should be easy for anyone who wants to use it.