Adaptec 1480 vs. 1480A vs. 1480B SCSI PCMCIA Cards for T60/61

[dances_with_woof]

Does anyone know the difference between the three versions of the Adaptec SCSI 1480 PC-bus card? There's a "plain" version without a letter, then A, and finally, B. I currently own "A". There's also rumored to be a rare "X" version for Mac computers. Adaptec is mum on their website, and seems to list almost identical compatibility between the three. CNET lists "B" as being compatible with Windows XP. This is all rather confusing.

[jdrou]

Pretty sure those letters are just new hardware revisions of the same device. Older versions might have some minor bugs that couldn't be fixed in the driver or possibly just more expensive to manufacture. (I also have an 'A' version.)
Similarly, I have 1460, 1460A, and 1460D which are functionally the same.