Sony Model Numbers

I have bought a Sony CRX230ED. Both the …ED and …A (sometimes called …AU or …A/U) models are sold 'round the 'net.

I’m wondering if anyone has decoded the Sony model numbering scheme.

My theory is that the Sony CRX230ED is the OEM version (…E…) of the retail EIDE/ATA (…A…) model, and that any firmware updates for the latter would work on the former.

Sony provides firmware update for the CRX230A at
but I’m wary about applying that update until I know that the internal electronics of the …E… and …A… part numbered models are identical.

So, in addition to asking that specific question, I’m also wondering if anybody has worked with Sony drives enough to know whether we can make a general statement about those model-number suffixes.

–Carol Anne