AMIGA 3.5's <-> IBM?????
7 messages in this thread
The Amiga low level disk format is one that the MS-DOS machines cannot
emulate. The Amiga, however, can emulate the MS-DOS format as in the
Consultron CrossDos product.
{@_@}
Why is that, in technical detail? I'm only vaguely familiar with disk
formats, but I didn't think the Amiga did anything particularly strange,
ala the Mac for example. And once upon a time, I saw an MS-DOS program
that purported to be able to read Amiga disk sectors in raw data (not file)
format. It was not a hoax "Amiga emulator" or any such thing, it was a
rather honest looking effort from someone in Germany. I tried it, I
couldn't get it to work.
The Amiga format has more sectors per track than the IBM format. The IBM
systems have the routines for reading disk in ROM, and only know a very few
track formats, and none of them match the Amiga format. Without modifying
the BIOS, or replacing it, the IBM machine cannot read any disk not known.
The second problem is the nature of the file structure of the Amiga. There
is no DOS like FAT, the directory entries are 512 bytes each, and include
many fields wich DOS does not know. In theory, a DOS machine could be
programed to read Amiga format disk. In practice, there is very little
demand, and a larger portion of Amiga users wish to exchange data with IBM
manchines than IBM users wishing to exchange data with Amigas. As a
result, the program gets higher priority in the Amiga community.
Gary Dunlap : Wyrd Software
: It just works like magic!
Modifying the BIOS for non-standard sectors per track isn't that
far-fetched, you can buy BIOS source from a dozen places in the back of any
PC magazine. Of course the directory structure is different, but I don't
think it's beyond the ken of Amiga-PC programmers. Doing anything under DOS
is never easy.
Admitedly it can be done, but what is the level of demand for DOS machines
to read Amiga disk? Can you imagin a company trying to sell a BIOS which
has as its primary extra the ability to read and write AmigaDOS disk? They
might be able to sell a few thousand! Of course they could just clame the
ability to format the disk at 880k density 😉
Gary Dunlap : Wyrd Software
: It just works like magic!
Careful, or the next thing you know, you'll realize that there ain't many
Amigas in the world, period. 🙂 Instead, turn your question around: of
all the Amigoids you know, how many would like a program on their PC, so it
could read Amiga disks? That's the size of the market. It wouldn't require
a new BIOS for the PC. It might require some alternate disk-reading and
decoding software, but I doubt it would require a new BIOS.
Heck, why not go even one more step further and design a Amiga emulator
board for the PC. To make it *really* hot, make it a LocalBus card. After
all, if CBM can make a Brideboard and Readysoft can do the Mac, why not put
the shoe on the other foot.
Oh well, just a stupid idea. 😉
Richard