Sony Magneto Optical Drive
Mini teardown thread

This is not a minidisc player

Might be confusing to ya'll westerners (myself included) what this actually is. TLDR; Japan lived in the C Y B E R future in the 90s and we didn't.

This drive uses 3.5" MO disks.

Lets dig in! Oooooh, hey wait? This seems kinda not what I was expecting.

Is that a 3.5" standard drive in a chonky enclosure??

I'm gonna go with yes. Also this is a SCSI drive!

Have a ribbon cable out to the external scsi ports. Molex power from the power supply. And another ribbon cable that turns the scsi id pins into a dipswitch.

There's our mini-scsi? connectors and scsi id dipswitch.

Lets flip that drive over and reveal its secrets.
Its screaming at us

Sony SMO-F331-99. Cool.

And yep, here's what one looks like as an internal drive bay. (Mine has an entirely different faceplate for the external enclosure)

OK I cant resist, lets pop the cover on the drive!
An NEC μPD70320 V25 cool! x86 based microcontroller!

Under the ribbon. uPD72050gm.. hmm few references, but one reference to "NEC SEMICONDUCTOR SELECTION GUIDE 1995" In we go.

There it is A MO disk controller! 230mb max size disc for 3.5" drives. Sourced pdf from Elektrotanya. Now at https://archive.org/details/nec_semiconductor_selection_guide_1995

M A G N E T O - O P T I C A L

MB86311A is a 16bit DSP
CXD8133R is an Automatic Laser Power Control
TLS1022 from TI, CXA8033N, etc are unknown at first pass.

Thats a wrap, we'll get some MO discs and try it out eventually! Please retweet and share the love

BONUS: Weird flex Sony, but ok.