Simon Owen schrieb:
Thomas Harte wrote:
Although I'm aware that my USB drive may be hard coded somehow not to
support anything other than the PC layout
That's pretty much it I'm afraid! USB floppy drives are seen as
simple block devices, and the linear->CHS mapping is done inside the
unit. I believe DD disks will always be treated as 9-sector 720K (and
HD as 18-sector 1.44M), so be missing the 10th sector of each SAM track.
I have heard rumours of USB drives with an unofficial way to change
the geometry mapping in the drive, but I've yet to find one myself.
Until someone creates something like a USB CatWeasel, you'll be unable
to access 10-sector disks on a Mac.
If I remember correctly, RealSpectrum Emulator was working with my disc
Drive on Parallel port (under Win98), so USB is a step backward.
You coded the fdrawcmd.sys? It should work with onboard floppy connector
under Win2K. I currently try to build RealDisc support into the disc
manager of Retro-X (The picture converter PC->ZX, SAM, QL, MSX, CPC,
C64, ...). I changed the code from example
HANDLE h = CreateFile("\\\\.\\fdraw0", GENERIC_READ|GENERIC_WRITE, 0,
NULL, OPEN_EXISTING, 0, NULL)
to PureBasic syntax:
Handle.l=CreateFile_("\\\\.\\fdraw0",#GENERIC_READ|#GENERIC_WRITE,0,#Null,#OPEN_EXISTING,0,#Null)
but Handle returns always -1. I guess, that's not correct. SimCoupe on
the other side works fine with real Discs.
Any idea what -1 means (long is signed in PureBasic, so it returns
$ffffffff in fact). If it would return 0, this means surely that
fdrawcmd.sys was not installed.
Even if I can't image original disks, is there any way I could use
this drive for some sort of data transfer?
You'd be much better off with an Atom Lite board in the drive 2 slot,
so you can share a Compact Flash card between SAM and SimCoupe. It's
faster, easier and more reliable than dealing with floppies. Edwin
can provide them if you're interested.
The USB drive situation could be improved, with specially crafted
disks that lock out the 10th sector on each track. SimCoupe could
assist by returning matching dummy contents for the inaccessible
directory and data sectors. You still wouldn't be able to use
existing 10-sector SAM disks, but 90% of the space would be usable on
new ones.
Si
Great idea! But maybe it could be easier to use a standard SAM Disc, and
create a dummy file, which has a Sector bitmap that reserves all sectors
nr 10 on the whole disc. I think, such a program could be easy coded on
SAM. A Image of 256 Bytes of the last directory entry, which is
precalculated and could be written on any disc, reserving sectors that
are not accessable from PC. Any files saved after that on this disc,
would be avoid writing these sectors, so no need to change SimCoupe.
LCD
