DD Disk on a HD Drive ?

[THX1138]

My A4000 has 2 high density drives (1.76),if i have a game on
a DD disk would these drives read it or not ?

Also,is an Amiga high density drive the same as a pc one ?

[Severin]

The drives will read DD disks with no problems (unless the disk or drive is faulty) and no Amiga HD floppy drives are not the same as PC ones, they work by spinning the disk at half the speed of DD and writing 22 blocks per track instead of 11, iirc PC's don't change the speed.

Somewhere I have the schematics for a small board that a m8 did to convert pc HD floppies to Amiga, Problem is I don't think he ever got it working properly

[THX1138]

Well my 1200 reads the disks fine......but neither of my disk
drives in my 4000 will read these disks !

Can't believe both of my disk drives are knackered !

If a game says its for the 1200,shouldn't this work on the 4000
as well ?

[jmmijo]

Originally posted by THX1138
Well my 1200 reads the disks fine......but neither of my disk
drives in my 4000 will read these disks !

Can't believe both of my disk drives are knackered !

If a game says its for the 1200,shouldn't this work on the 4000
as well ?

Try this out, take a blank or any DS/DD floppy and format it in one of the A4000 drives then copy a file or two onto this disk. Now insert the disk onto your A1200 and see if you can read it or not.

If not then I'd say that there is something wrong with the A4000 drives or your A1200 drive, i.e., out of alignment.

Also get a blank DS/HD floppy and try the same thing out only this time see if the other A4000 drive can read the disk formatted on the first drive and vice-versa.

[THX1138]

Good idea !

I conducted various tests but only using HD disks,and came to the conclusion that if you formatted a disk in a DD drive,only DD drives could read this & if you formatted a disk in a HD drive,only HD drives could read these.

If i formatted a DS disk in a HD drive,wouldn't the DD drive be able to read this as well ?

If this is correct then the problem is sorted,but if not........

[jmmijo]

Originally posted by THX1138

If i formatted a DS disk in a HD drive,wouldn't the DD drive be able to read this as well ?

If this is correct then the problem is sorted,but if not........

Yes, remember that a HD drive can read/write to both types of media, DD and HD, where as a DD drive can only read/write to one type of media

[Unknown_K]

Im not sure how 3.5" drives do the data. I know the magnetic medium is different so that HD disks can store 2x the data on the same media. Changing the magnetics means the write head must have different magnetic properties.

I do know old 5.25" disk drives have different size heads for 360k and 1.2m. A disk formatted on the 1.2mb drive cant be read on the 360k drive reliably because the data track is narower or something to that effect.

Maybe the DD HD 3.5 drive is the same way?

Dont think I have ever seen a real 720K drive on a PC, since they pretty much started using the 1.44 HD drives from the start.

[THX1138]

I understand fully....but i do have one nagging problem...

Using my 1200's DD drive i copied a game onto HD media and this works fine ?

[jmmijo]

Originally posted by THX1138

Using my 1200's DD drive i copied a game onto HD media and this works fine ?

Clarify please, are you asking if this will work or are you stating that it does

Here's the skinny on using HD media on a DD drive, some say there isn't a problem and it works for them and others have had problem, i.e., the disks will not format or if they do the format degrades so fast that it's not usable!!!

One thing that everyone seems to agree on and it should be noted here is that if you plan on using a HD floppy disk on your A1200 to copy files over to it then use this same disk on your HD A4000 drive then please cover the HD hole with a piece of tape or a write protect tab like from the old 5.25" floppy disk days This way the A4000 HD disk will not detect this as a HD disk and treat it as a DD disk, got it

[Severin]

yes it will work fine in a DD drive but a HD drive will not recognise it unless you cover the HD hole (the other side from the write protect hole) with a bit of tape on the bottom side...

if the games you tried on the 4000 were on HD disks written on your 1200 there is no way they will work until you cover the HD hole...

basically HD drives have an extra switch that is pressed down by DD floppies, so cover the hole to convert HD floppies to DD. Though this is not a really good idea as the media is different and you will get more errors on DD drives using HD disks

[THX1138]

Thanks Severin & Jmmijo for that crash course in DD & HD drives and media.....thanks a lot !

[jmmijo]

Glad I could help