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8" Flippie disk

Lorne

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For those that haven’t seen a flippie before, here’s a photo of a manufactured 8” flippie disk.

Flippie disk.JPG

Note the label:
Single head, double side,
Soft sector, single density

It had me stumped when I first read it – single head but double side? Huh?

Before double sided drives became popular, flippies were used to double the capacity of the disk.
Both sides of the disk were good, so an extra index hole was punched allowing you to use both sides by flipping them over.

In case you notice the lack of a write protect notch:
Unlike a 5 ¼” disk where you need to cover a notch with a piece of tape to write protect it, it’s the opposite with something like an 8”Shugart 800 drive.
This disk does not have a notch, so it is not write protected – if you want to write protect this disk, you need to cut a notch in the disk.

The flippie is ideal for my Altos 8000, as on their early models Altos mounted the drives upside down (there were apparently no standards on how to mount the drives back then), so I have to insert the disk label side down (the opposite of most drives) and it’s easy to forget that. Now I can make both sides bootable, and I won’t have to worry about which side goes up or down.

(I wonder how long it’ll take GanjaTron to ask if he can get one of these disks for his Altos). ;)
 

Lou - N2MIY

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I make these myself to use as dec RX01 or RX02 media. I have an old jacket (media removed) that I use as a marking template and use a fine point Sharpie to trace the sector hole location on the back and front of the jacket of the disk being made into a flippy. Then, I protect the media surface with a business card and use a hand hole punch through the spindle hole to punch out at the locations marked. It works fine!

This method can also be used to make double sided disks into single sided (since the sector index holes are in different places for SS and DS.)

Lou
 

Elvi

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I said similair not a direct thing heh and i know about the index hole.
Think i'll have to see what my 8" look like one of these days, i have have a 10pack of unused ones lol but i have no 8" drive nor any computer that could handle a drive like that :(
 

Lou - N2MIY

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Terry,

The double sided disks I have seen do not have the hole in the right place to satisfy a single sided drive. The single sided sector hole is closer to (but not at) the 12:00 position, while the double sided hole is closer to 1:00.

Put a double sided disk in an SA800 and you will see that the sector hole in the disk does not line up with the sensor in the drive.

Lou
 

MikeS

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I think there's some confusion here about 8" 'flippies' and single/double-sided disks (as there often is ).

As Lou says, on a 'normal' (non-flippy) disk the location of the index hole in the jacket is different for single-sided disks vs. double-sided disks; of course the location of the index sensor was correspondingly different in the single vs. double-sided drives as well, although many double-sided drives had two sensors and could use either type.

However, as Terry says, you could get double-sided disks with both holes that you could use in either type of drive; you just covered the unused hole with a sticker if you were using the disk in a double-sided drive that had two index sensors. Here's one with the sticker removed to show the holes:
8index.JPG

Note that both holes are on the same side of the centre line; a 'flippy' would need the SS hole duplicated symmetrically on the other side of the centre line as in Lorne's picture.

So, 8" diskettes could have four different hole locations.

In systems that could use 5 1/4" 'flippies' (Commodore, Apple etc.) the index hole was irrelevant because those systems did not use an index sensor at all; as mentioned above, there you had to duplicate the write-enable notch on the opposite edge of the disk in order to be able to write.
 
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Lorne

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However, as Terry says, you could get double-sided disks with both holes that you could use in either type of drive; you just covered the unused hole with a sticker if you were using the disk in a double-sided drive that had two index sensors. Here's one with the sticker removed to show the holes:
View attachment 7835


MikeS - you're making my head hurt !

If the idea was to use both sides of a single sided disk, why would you ever need two holes for a double sided disk? Wouldn't you just use it in a double sided drive?

a. SS disk with one hole = use one side in a SS drive
b. SS disk with two holes = use both sides ina a SS drive
c. DS disk with one hole = use both sides in a DS drive, and use 0 sides in a SS drive
d. DS disk with two holes = why? (maybe use both sides in a DS drive and one side in a SS drive? To use two sides in a SS drive wouldn't you need three holes?)

Edit: OK, I just re-read it - the disk you show could be used in a DS or a SS drive, but it couldn't be flipped over to use both sides in a SS drive, correct?
 

MikeS

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Ouch! Now you're making my head hurt ;-)
If the idea was to use both sides of a single sided disk, why would you ever need two holes for a double sided disk? Wouldn't you just use it in a double sided drive?
Yes, but unlike your flippy the idea here is to make a double-sided disk that can be used in either a single or a double-sided drive; you shouldn't use both sides of a single-sided disk but obviously you can use only one side of a double-sided disk, but the index hole sensor is in the wrong location in the SS drive.

The disk in the picture is a software update disk that has to be usable in both types of systems, those with SS drives and also those with DS drives; otherwise you'd have to make, track and distribute two separate versions. Similarly, if you were selling 8" diskettes you'd have to keep both types in stock instead of just the one-type-fits-all with a sticker.

Edit (replying to your edit):
Edit: OK, I just re-read it - the disk you show could be used in a DS or a SS drive, but it couldn't be flipped over to use both sides in a SS drive, correct?
Correct; to use both sides of a DS disk in a single-sided drive you'd have to make a hole symmetrically opposite the SS hole as in your picture, whether there's an extra DS hole or not (the second side would of course be completely incompatible with a DS drive unless it had dual sensors or you made a fourth hole ;-) ).

I was just throwing in my .02 because it looked like Lou was not aware that disks were available with both SS and DS holes, and Terry on the other hand seemed to assume that all DS disks had both holes.
 
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Terry Yager

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Fortunately, I already had a headache before hitting this thread. Yeah, I was kinda thinking of, f'rinstance, Trash-80 media which had to be distributed in a form usable in both the Mod II and the 16-series (but not as flippies).

--T
 
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Chuck(G)

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For those of you with older Altos systems that use "upside down" floppy drives, this can be confusing. My Memorex flippies have a label on both sides--one says "Side 1", the other, "Side 2". Altos would put their disk labels on the "up" side, so that the first side label appeared on the side labeled "Side 2".

Now, if that doesn't give you a headache, I don't know what will...
 
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