ahh, the HP 9133A - the largest and heaviest external 3 1/2" floppy drive ever built.
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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?
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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.
@tomjennings @tubetime Oh my god, FAT IDs!
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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.
@tubetime I've only ever seen those on arcade boards and cryptographic equipment....
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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! 🧵
Does that have HP-IB interface?
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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.
@tubetime I was gonna say, that looks a lot like an OA-D3X drive!
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@mwichary worse, it is 270K and it uses 256 byte sectors. it also runs at 600 rpm!
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@tubetime Does it take “common” 3,5” disks?
Or were there disks you could flip over?@nblr @tubetime Probably regular disks? But the earliest ones (I think just the OA-D30V but I’m not sure) used disks with a latching shutter. https://www.jamiecraig.com/early-floppy-disks/
I’m pretty sure there was never a flippable 3.5” disk.
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and it tests good! the weird 26-pin HP interface is natively supported by my Floppy Exerciser board (https://github.com/schlae/FloppyExerciser)
@tubetime I think the 26-pin interface is actually just Sony’s original interface. It’s also on the D30/32’s used on the ACT Apricot.
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and it tests good! the weird 26-pin HP interface is natively supported by my Floppy Exerciser board (https://github.com/schlae/FloppyExerciser)
@tubetime Neat seems HP was a fan of Sony drives, My HP1653B logic analyzer also has a Sony drive with HP specific interface though that one is 3.5 inch
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@FurryBeta @tubetime 20MB, sister to the 40MB ST-251. I really liked them though the bearings certainly got noisy over time.
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@FurryBeta @tubetime 20MB, sister to the 40MB ST-251. I really liked them though the bearings certainly got noisy over time.
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Does that have HP-IB interface?
@vk3kri yes
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and it tests good! the weird 26-pin HP interface is natively supported by my Floppy Exerciser board (https://github.com/schlae/FloppyExerciser)
on to the surprise hard drive. but, no surprise, it won't spin up and pulls a bunch of current on 12v. hmmm.
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on to the surprise hard drive. but, no surprise, it won't spin up and pulls a bunch of current on 12v. hmmm.
the motor won't move. I think it is stiction. ugh.
