finally got one of these cool MFM hard drive emulator boards! it can pretend to be a hard drive or it can analyze one.
plugged into one of my ST-412 drives.
it works!
maybe I should use it to analyze the drive in this HP9133. yeah there's a hard drive inside it.
the drive uses HPIB to connect to the host computer, so it has a controller board built in.
told ya there's a hard drive inside. it even has a bezel.
it's an ST-419.
looks familiar. very much like the ST-412.
interesting, it detects the controller format.
archived! the drive is also running a lot quieter. i'm running it upside down like @WysWyg_Protogen suggested for my ST-412s. once the lubrication warms up, it can flow back down into the bearings.
the HP 9133 uses a weird early Sony floppy drive. they tend to get gummed up so I'll need to take it apart to check the grease. if you don't do this, the disk won't eject, and if you yank on it, it'll tear out the upper read/write head.
sure enough it was a bit sticky. I added some grease and freed it up.
well, the controller isn't happy. I think there were some bad sectors at the beginning of the drive, so that's probably why
the diagnostic test jumper was on. it's set to a floppy drive test, and there's no disk in the drive, which is probably why it failed.
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i printed a new panel insert that has two BNC sockets on it (the original probes would have had captive cables)
the tricky part is that this oscilloscope has a 333K ohm input impedance instead of 1M like umm every other scope on the planet. fortunately someone designed a little conversion circuit...
in honor of Sim Wong Hoo, here's a quick historical review of the Sound Blaster! 🧵
but first we have to go back to their first sound card, the Creative Music System from 1987. (image credit: Bratgoul on Wikipedia)
this card has some special "CMS-301" chips. if you peel back the sticker, they have had their top marks removed. they're actually SAA1099 synthesizer chips made by Philips. Creative wrote music composition software for musicians on the PC.