5,25" Floppy Disk drive working under Win 7

[drussell]

This American laughs at your mention of insulated pins and 10A ratings.

I've shoved decent loads though the cheap chineese cables fairly fine, but most of mine are nice and beefy cables.

Insulated pins, perhaps, but, while you can still find cords with 14ga or more often 16ga wires, most of them are supposedly 18ga... and many are not even close to that.

That is fine for a couple hundred watts into a typical desktop computer or a DVD player or something but is totally inadequate for many purposes, and if it was made in China any time recently, you can't come anywhere close to relying on the "14/16/18ga" or xx mm² numbers on them.  They are often a complete lie, and anything less than 18ga is always completely invalid for mains unless it is "tinsel cord" for Christmas lights.

They shouldn't even be let into the country in case someone who doesn't know how dangerous they are uses one improperly.  I've seen many, many very scary ones!

[Halcyon]

This American laughs at your mention of insulated pins and 10A ratings.

Even decent consumer cables running 10A @ 240v is enough to make them noticeably warm. Connect a kettle or a decent toaster here and they pretty much draw 2400 watts and the cord is warm to the touch. Try that with thin, shitty cord from China and you'll have yourself a fire.

[Ampera]

This is where my EE skills devolve a bit. My current working theory on the principle of cable gauge is that the larger the current passing through the wire, the larger the gauge needed to support the current, and possibly the resistance of the wire increases proportionately to the current, but disproportionately to the gauge of the wire? To further, is it true that voltage doesn't affect any of this?

I never went to school for this (yet) so I am working on extrapolated knowledge here.

In terms of total power, US 120V 15A sockets are limited to 1650W (if W = V*A, apparently there's something to do with resistance or load, or batteries, idk, if I actually was properly on topic in this forum, I would be a total idiot with what I say).

We actually own a kettle which (claims) to draw 1600W. I think it's closer to 1200W, but either way, is nothing like the snap instant kettles I've seen in Germany (where I believe most circuits are rated for 230V 16A?). It's faster than using a stove kettle (which is what most Americans use, or a microwave). People get really confused that we don't have many electric kettles, and I personally don't use it for anything but heating up my noodles, as tea isn't massively popular here. It's still drunk, and people use different sorts of methods for hot water, but we don't actually tend to have a need for a massively dedicated solution.

We do have egg plates, though, which go unused because whenever we eat eggs they are almost always fried, and soft boiled eggs haven't been made in this house for years. We also just eat hard boiled eggs on a regular plate (or in a salad).

Man, I'm bad at moving off topic. Let me fix that. I actually use floppies quite a lot, as they are easy to move over things like drivers and really small files, especially when the only other alternative is burning a CD (some of my machines don't have DVD rewriters, and CD-RWs are painful to use). I have a 5.25 inch drive for IBM compatibles, but I never use it because it's in a combo drive which for whatever reason is always configured to use the 5.25 inch drive as drive A.  I don't have any real diskettes with anything on them to use on it anyways.

[ebastler]

This is where my EE skills devolve a bit. [...]

So, is that a long way of saying that your earlier post about the worthlessness of NEMA ratings and other standards was, perhaps, a bit misguided? 

[Ampera]

This is where my EE skills devolve a bit. [...]

So, is that a long way of saying that your earlier post about the worthlessness of NEMA ratings and other standards was, perhaps, a bit misguided? 

I've gotten very good at insulting things I know almost nothing about. What do you think I do here? 

I know enough general knowledge (and have overheard enough EE debates) to make different forms of conclusions. Most of the standards are mechanical anyways, and that's what I was mostly getting at, as I can understand the mechanics of the designs a bit better than I can the electrics of it. Flimsy contacts, little to no safety features (I have never seen a shuttered NEMA 5-15 outlet in my life despite living in the US, and them being mandatory on all new installations) with stuff like insulated connectors, any sort of electrocution protection of any sort (Even I have shocked myself on an outlet once) and the most significant safety feature being that our 2 prong connectors have a bit of molding around the edge to prevent your fingers from slipping.

[djos]

Hi,

recently I was thinking about what to do with my old Shuttle barebone. Model SK41G with Athlon XP on board.
Then I noticed the headers for the ribbon cable for the floppy disk drives and remembered the lot of 5.25" floppy drives, laying somewhere in a box.
Some time later, I got the system running: "SSD" with 16 gigabytes on an IDE/PATA adapter, 3.5" and 5.25" floppy drives. First boot: all drives detected by the BIOS, the drives performed the typical "floppy seek" sound (how long was it, having heard it last time?).
Then - within a short attack of mental derangement - I installed Windows 7 on that system. And it works. Remarkable: Win7 has a dedicated black disk icon for 5.25 floppies. They can be read and written. Only drawback is formatting, which is not supported.
Performance of the PC is not that bad due to the flash disk, 2 gigs of RAM and the Athlon running at 2 GHz.

This machine is now my "old floppy disk to USB stick converter".

Tom

You should be able to format disks from the Command line in Windows 7 - even 720kb disks need you to specify the Tracks etc to format under windows 7.

Here's the info you need:

720kb 3.5" = FORMAT A: /T:80 /N:9
360kb 5.25" = FORMAT A: /T:40 /N:9

1.44MB 3.5" = FORMAT A: /T:80 /N:18
1.2MB 5.25" = FORMAT A: /T:80 /N:15

/T = Tracks, /N = Sectors per track

be aware that 5.25" disks formatted and written to with a HD drive, wont work in an old machine with a 360kb drive as the bit density is too different.

[james_s]

be aware that 5.25" disks formatted and written to with a HD drive, wont work in an old machine with a 360kb drive as the bit density is too different.

IIRC the reason is that the 1.2MB drives have a narrower track, and double the step resolution of the head positioner. This means that the head of a 1.2MB drive cannot be placed directly in the center of a 360k track and the track it writes is not wide enough or centered under the head of a 360k drive.

[drussell]

be aware that 5.25" disks formatted and written to with a HD drive, wont work in an old machine with a 360kb drive as the bit density is too different.

A double density disk will read fine in a properly adjusted 360k DD drive if it is written in a 1.2 meg HD drive if the disk was first formatted from new or from being bulk-erased in a properly adjusted 1.2 meg HD drive.  It is when you start writing over the stuff written in the HD drive with the SD drive, then write again with the HD drive that you will usually start to have problems because the HD drive won't completely write over anything written in an SD drive. 

Something written over a real, full DD track with an HD drive will usually read fine in the HD but not in an SD drive.

[james_s]

I remember having a lot of trouble trying to read a disk in a 360k XT drive that had been written in a newer PC. It may vary from drive to drive or from one disk to another though.

[drussell]

It absolutely varies from drive to drive and with the accuracy of the drive alignment but the biggest problem reading something from a HD drive in a DD drive is always disks that were not written exclusively on the HD drive.  As soon as you write over a sector using the wider head on a DD drive, even if the (DD) disk was formatted and used exclusively on an HD drive before, you've now messed up that sector's ability to be written reliably on an HD drive.  You need to start again on the HD drive or write only on a DD drive.  Having a 360k drive around just for writing SD/DD disks is very handy since you know it will always read correctly.  (Assuming the drive is good and in proper alignment, of course!  )

As long as you have only ever written to the disk in an HD drive, it should always READ fine in a DD drive.  As soon as you write to an area, you won't be able to reliably write OVER that part using an HD drive, (though it often still works... sometimes... at least with a good drive...  )