ahh, the HP 9133A - the largest and heaviest external 3 1/2" floppy drive ever built.
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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!
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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.
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whoops, surprise hard drive inside!
this one is a Seagate ST-506, a MFM drive with a whopping 5MB capacity!
@tubetime it's MFM Monday!
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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.
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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.
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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!
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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.
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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?
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a single-sided 3.5" drive head is something you don't see every day. they were never that common.
i'm taking it apart this far because the drive mech needs to be cleaned and relubricated. the old grease hardens and makes the mechanism go sticky, so you'll be able to insert a disk, but when you try to remove it, it'll tear the head right off!
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@tubetime Is that like… 360KB capacity?
@mwichary worse, it is 270K and it uses 256 byte sectors. it also runs at 600 rpm!
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a single-sided 3.5" drive head is something you don't see every day. they were never that common.
@tubetime Does it take “common” 3,5” disks?
Or were there disks you could flip over? -
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.
it was made by an OEM that spun off xebec
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it was made by an OEM that spun off xebec
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i'm taking it apart this far because the drive mech needs to be cleaned and relubricated. the old grease hardens and makes the mechanism go sticky, so you'll be able to insert a disk, but when you try to remove it, it'll tear the head right off!
and it tests good! the weird 26-pin HP interface is natively supported by my Floppy Exerciser board (https://github.com/schlae/FloppyExerciser)
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ahh, the HP 9133A - the largest and heaviest external 3 1/2" floppy drive ever built. let's get it working! 🧵
@tubetime That layout of the floppy and hard drive recalls the drive assembly I saw when I worked at Westinghouse, except it was a seagate ST-220 and a 1.2MB 5.25” floppy. Controller board was in a separate Intel Muktibus style chassis tho
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@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.
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it was made by an OEM that spun off xebec
@bitsavers that's wild
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@tubetime That layout of the floppy and hard drive recalls the drive assembly I saw when I worked at Westinghouse, except it was a seagate ST-220 and a 1.2MB 5.25” floppy. Controller board was in a separate Intel Muktibus style chassis tho
@FurryBeta @tubetime ST-225?
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@tubetime Is that like… 360KB capacity?
Single sided single density 5 and a quarter drives were like 85kbytes i think. Even at that time it was miserable. And slow.
Ibm pc single sided were originally 160k, later 180k, as they fitted another sector per track.
In a couple of hours my brain will involuntarily regurgitate the FAT IDs for them.
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@FurryBeta @tubetime ST-225?
