ahh, the HP 9133A - the largest and heaviest external 3 1/2" floppy drive ever built. let's get it working! 🧵

whoops, surprise hard drive inside!

this one is a Seagate ST-506, a MFM drive with a whopping 5MB capacity!

after taking out 894375037 screws, the actual drive reveals itself.
oh yeah, the hard drive has a controller board on top of it. and on the controller board is this super weird potted electronics module. i'll have to look into that later.
the floppy drive is the extremely ancient Sony OA-D31V-1. it's not the first one to come out. more like the second one.
transmissive optical sensors hate dust bunnies. they'll produce false readings, so they must be cleaned!
a single-sided 3.5" drive head is something you don't see every day. they were never that common.
@tubetime Is that like… 360KB capacity?
@mwichary worse, it is 270K and it uses 256 byte sectors. it also runs at 600 rpm!
@tubetime You say “worse,” but all of this sounds awesome. 😀