Midwest (eBay) Memory Punch II - "Speed Shift 3.5" Diskettes 720k to 1.44 Meg"

[nullvalue]

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Spotted this unusual diskette device on eBay and thought I'd share.. https://www.ebay.com/itm/304687458492

I've heard of notching devices for 5.25" disks, but never seen one for 3.5" disks before.. I'm so tempted to buy this just for the novelty of it.

 

[Timo W.]

Given that it does not really work that way, no wonder that these appear only rarely. Reminds me of SoftRAM somehow.

 

[tofro]

Well, of course you can format a punched 3.5" DD disk to HD. It will appear to work, because the traits of the magnetic media on these disks is close enough (much closer than DD and HD are in the 5.25" realm). But not close enough to work reliably.

 

[Caluser2000]

A soldering iron does a better job....

 

[Timo W.]

Punching the hole is not the problem with this...

 

[Caluser2000]

It makes me happy....

 

[SomeGuy]

A lot of people did that. Around 1990 or so one could buy huge no-name bulk packages of "720k" 3.5" floppy disks at Microcenter and then punch a density notch in them - and they would usually work fine. I've still got a lot of them that were formatted high density back then and are still readable.

The catch is that pedantically the magnetic material differs between 720k and 1.44mb disks. A proper 720k disk shouldn't be reliable as 1.44mb or vice versa. But in practice, it often works well enough.

One theory is that towards the end of the 720k era, manufacturers may have reformulated the magnetic oxide material to sort of fall between the two specifications. I can easily imagine a low-end product manufacturer packing the same material tested high-yield as 1.44mb and the rest as 720k.

 

[Plasma]

These days DD disks go for about 2x the price of HD disks, so you'd be punching yourself in the wallet by using this contraption...

 

[krebizfan]

Those were somewhat necessary for disks that had been created on a PS/2. Most of the floppy drives used on PS/2s did not check the media hole so many DD disks were inadvertently formatted as high density. Other systems wouldn't read the wrong format without the extra hole.

I have my doubts that any punch would have completely removed all excess plastic remnants. It does not take very much to damage the coating on a cookie.

 

[Chuck(G)]

Back when HD 3.5" disks made their first appearance, they were considerably more expensive than the DD variety--and a bit harder to come by at your local computer store.
I confess to having done maybe a dozen disks this way--I had a jig for my drill press. A 1/8" bit made short work of the perforating.
Now, this is worth knowing--not one of those disks survived intact--and the customer disks that I've received over the years have suffered a similar fate.

Sure, they'd hold data for a few months or even a few years. But eventually, they'll all fail. 3M and other manufacturers warned us.

People often point to the similarity in coercivity of the coatings of HD and DD disks--but they miss the bigger picture--particle size and coating thickness.
Eventually the price of HD 3.5" disks came down to the level of DD. ED ones never, in my experience, did however.

 

[nullvalue]

I find it more amusing that this is the "Memory Punch II".. like, is there a "Memory Punch I" revision out there somewhere?

 

[Plasma]

I'm willing to bet the Memory Punch I was for 5.25" floppies. Either way it's not great marketing, but maybe unintentionally honest. Nobody ever got punched and had their memory improve... 🥴

 

[nullvalue]

I'm willing to bet the Memory Punch I was for 5.25" floppies. Either way it's not great marketing, but maybe unintentionally honest. Nobody ever got punched and had their memory improve... 🥴

Yeah but how's this for marketing: "Powder Painted (Baked on Finish)" - just in case you were eyeing a competitor that used traditional paints or dyes, I think this would all but force you to make the purchase. That's the clincher, right there.

 

[Chuck(G)]

Make my chrome-plated or stainless steel. Of course, today, everything but the punch die would be plastic.

 

[nullvalue]

doh! someone snagged it.. seller wasn't accepting any of my offers.. hope one of you got it