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Model II disks

JonB

JonB

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Hi

Quick question (edit: "questions") here... I just took delivery of a box of 3M DS/DD 8" floppies for the Model II. They were sealed and rather expensive. But, rare enough so I paid up.

Now, on formatting I get a "Drive not ready" error. Odd, but then I noticed the index hole is not in the same place as the Tandy disks! Is this because Tandy made it so they could sell their own branded "certified" disks, or is it because I am using DD on a SD drive?

I suppose one could punch new holes? Any advice on how to do this? Perhaps using a leather punch (they are like pliers) I could do it without removing the disk from the envelope. It should slip in though the central hole. Anyone tried this? I really want to use these on the MII because they are almost completely silent in operation, whereas the Tandy ones which are old and very dirty are really noisy, and I expect they have very little life left in them after 35 years.

Thanks
JonB
 
I have dealt with precisely this problem. I wasn't able to figure out if the index hole was in a different location as a proprietary thing or because these are DS/DD rather than SS/DD, but it is a tricky issue.

What I did is make a jig that I can put the floppy into and carefully cut an index hole on each side. This may sound harder than it needs to be, but in fact it needs to be this hard. The problem is that there is already an index hole in the floppy itself, it's just the hole in the outer media that is the problem. If you just punch a hole clear through you will likely create a hole that is too large -and- will now have two index holes.

Another option is to slice open the edge of the outer shell and slip the media out first. Then a simple hole punch will do. If you go this route you could also slice the end of a non-working SS/DD floppy that you have and slip the media into it using it as a sort of "caddy' for your floppies.

JonB said:
Hi

Quick question (edit: "questions") here... I just took delivery of a box of 3M DS/DD 8" floppies for the Model II. They were sealed and rather expensive. But, rare enough so I paid up.

Now, on formatting I get a "Drive not ready" error. Odd, but then I noticed the index hole is not in the same place as the Tandy disks! Is this because Tandy made it so they could sell their own branded "certified" disks, or is it because I am using DD on a SD drive?

I suppose one could punch new holes? Any advice on how to do this? Perhaps using a leather punch (they are like pliers) I could do it without removing the disk from the envelope. It should slip in though the central hole. Anyone tried this? I really want to use these on the MII because they are almost completely silent in operation, whereas the Tandy ones which are old and very dirty are really noisy, and I expect they have very little life left in them after 35 years.

Thanks
JonB
Click to expand...
 
Most people just marked the location of the index aperture in the jacket on both sides and then, using a hand punch (like a conductor's ticket punch; available at most office supplies store very inexpensively), slipped the punch around each side of the jacket and punched a hole. All that's needed is for the jacket holes and the "cookie" index hole to line up. No need for jigs or to disassemble the floppy.

Alternatively, the drive, if it has an index sensor in the proper location, can be jumpered to use either placement and no modifications need be done.
 
Chuck, that's what I was suggesting. Slip the bottom jaw of a hole punch into the big central hole, with care. Both sides. Might need a template to make sure the new holes are matched perfectly. Nice to know it is possible, thanks. :)

It is an old Shugart drive. But if it is jumpered (assuming it has 2 index sensors) I won't be able to copy from the Tandy disk to the 3M, which I need to do. There is only a single drive and I doubt resetting the jumpers at the disk swap prompt is going to work. I'll need to try something, though..
 
On the Qume drives that I have, the sensors are OR-ed, so either type of disk works. Every once in awhile, I get some of the "hole added" disks and have to cover over the appropriate hole (I don't want to change the jumpers on the drive). The side benefit is that I can use either type of disk (SS vs. DS) with no added hole-punching.

Which Shugart drive do you have?
 
I don't know the drive type. They are standard early Model II. I've been looking online and so far I haven't found the model number (away from home now so can't look)..
 
Punching the SS index hole would be just like what I used to do on my Color Computer to make flippable disks (I had a DS drive and controller, but flippable disks were still a money-saver when using the regular Radio Shack SS formats). I cut out two items from a manilla file folder:

1) A template to let me mark the index hole and write enable notch locations.

2) A strip, just a bit narrower than the hub opening in the jacket, which I would slip between the jacket and media to protect the media from scratches while I punched the new index hole (on both sides, one at a time) with a plain old single-hole punch.

I must have read how to do that in a magazine, because I don't think I was creative enough to come up with it on my own. :)

I believe that the slimline DS drives in my 12 and 6000 can use either kind of disk, but the II's drive will naturally need the index hole in the SS position. I think you should also be able to make those DS disks into flippies for your II, as long as there's no crud on the felt pressure pad that will scratch the back side of the media.

BTW, the Apple II folks had it easier. Since their drives didn't use the index hole, they just needed to add new write enable notches to flip their SS disks.
 
Some remarks about modifying the 8" diskettes.

To make a new index hole without damaging the disk I use a template to mark the new holes.
I use a small metal ruler and protect the backside and the left, right and frontside with a few layers of tape.
Now I can easy insert the ruler in the jacket and with a very sharp hobby knife I cut a square that has the outer size
of an index hole in each side of the jacket.

To make a flippable disk you can use the same technic, but there are 2 reasons not to use
flippable disks.

Mostly factories use double sided media with one bad side for making single sided disks.
So you can expect sooner or later error on the backside.
But more serious is the way a disk works. In the inside of the jacket is a layer of a hairy material.
This is done the reduce the friction of the disk. But it is mostly there to catch dust and
other material to prevent damaging disk and the head.
Each time you flip the disk it is turning the other way around and all the dust is getting free and could seriously damage
the disk and drive.
 
@NF6X: That's exactly what I had in mind. So SS/DS is the reason why the index hole location differs; thought so. Making a flippy is an interesting idea as these floppies were expensive and it would be nice to get more out of them. Ha, it'll feel a bit like using a single sided Amstrad floppy (horrid little 3" hard cased media).

@Hans01: I did wonder whether rotating the disks in both directions would lead to problems with the liner, but these are brand new (old stock, sealed in the box) disks, so there won't be any muck in the jackets yet. Since they are DS, there shouldn't be any problem flipping them (from the errors perspective), but I will probably only try it when I've used all but the last disk. Since they hold about 500K each I will probably not run out too soon. I imagine making backups of the old media's going to eat most of them.

However it will all have to wait until I refurbish the keyboard (which I must say has a most agreeable tactile response). Got keys dropping like flies, and every time I swap one out for a lesser used one, I get another "death". So it's out with the q-tips, alchohol, replacement foam pads (when they arrive) and a shed load of patience.. :roll:

I suppose the refurbishment of retro computers is part of the fun. Sigh.
 
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"Flippies" were certainly made commercially in the 8" size--I have several of them--so they weren't strictly hobbyist projects. In the beginning, 8" floppies were expensive.
 
I'll add that it's also possible to use hard-sectored (i.e. 32-sector) floppies as soft-sector ones on some drives. Simply jumpering for hard-sector use allows the drive to detect the index pulse--one just sets up for hard-sector use and ignores the output of the SECTOR line.
 
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