today on The Bench of Healing™ -- an original IBM 360K 5.25" drive.
it's very dusty
ooh there's a floppy disk still inside! it's also very dusty
IBM SOURCE INSPECTION. what does H/T mean 🤔
yep, dusty
this drive has two heads. the original IBM 5150 came with a single-sided drive at first, with a capacity of 160K (later versions of DOS extended this to 180K)
you can use a strobe light to adjust the motor speed.
if you look underneath the drive latch, you can tell that this is a 48 track per inch drive, double sided recording.
discovered that the plastic guide rails are just press fit into the metal casting. naturally the plastic tabs had broken off at some point. let's see if a little glue will hold.
hooked it up to my bench PC, let's see what it does.
the motor speed is dead on!
why won't it work, he asked stupidly, while holding the connectors from the rear/write head. 🤦♂️
much better
yeah this isn't great. I'm thinking about how to remove the plastic pegs
decided to drill into it and thread a screw in
snip
drilled holes in the other piece so they fit together
this provides a lot more surface area for the glue.
removing dust using my new favorite tool: ColorCoral.
here's another drive. someone's put a RAM chip in the socket meant for the terminator resistor array 😂
something is wrong with the belt. can't quite put my finger on it 🤔
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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.