Thomas Harte
Sun, 22 Jun 2008 05:06:19 -0700
What sort of floppy format were Apple using in 1997? Would obtaining one of the very original USB floppy drives that were intended for people moving to the iMac be of any advantage?
On 22 Jun 2008, at 11:38, Leszek Chmielewski wrote:
Simon Owen schrieb:Thanks, it now seems to work, the handle is now every time 892. I never used C before, so I did not knew that trick :-[ . Btw.: you wrote, RealSpectrum Emulator use Fdrawcmd to read discs. I tried to read +D discs under Win2K, but Sector 10 is bad on every disc (Directory sector 10 is corrupted), SimCoupe reads all directory entries correctly. I guess RealSpectrum use a older version of Fdrawcmd, because it works fine only under Windows 98SE or older. The newer RS32 has no ability to read real discs.Leszek Chmielewski wrote:You coded the fdrawcmd.sys? It should work with onboard floppy connector under Win2K.Yes, and yes :-)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.The actual path being opened is \\.\fdraw0, but the backslash charactersneed to be escaped in C by adding additional backslashes before each.Try changing "\\\\.\\fdraw0" to "\\.\fdraw0" and see if that works. Ifit doesn't, check GetLastError() to see what it returns. If you're still having trouble, e-mail me off the list and I'll look into it.I though, you want to modify SimCoupe to format and write discs with 9 sectors, that means, need to change the ROM, File Bitmap layout, etc.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 10on the whole disc.That's pretty much what I had in mind, but with additional dummy entries to reserve sector 10 on the directory tracks. 2 hidden entries can be added to each, to prevent the listing stopping so the remaining entrieswill be searched.When the image is used in the emulator, saving will not use sector 10 in the directory since it has hidden files in it. The dummy file preventssector 10 being used across the rest of the disk.Thats what I mean too.So you automaticaly can recognise USB Drives, I guess. I never used USB drives and have no Apple here, but Mac users have no other chance to connect a floppy drive, if they got no internal floppy connector.To write to a USB floppy drive would just need the 10th sector to bedropped, and the remaining 720K written to the raw device. When openingthe USB drive in SimCoupe, the emulator will need to provide suitable dummy details for every sector 10.Oh, I forgot about writting dummy sectors to directory sectors 10. So 8+1 Entrys needed, so this will reduce the number of saveable files to 71. But for data transfer needs it does not matter very much. The dummy entrys did not need to have a bitmap.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.If there are more than 17 files on the disk, getting a directory listingwould attempt to read track 0 sector 10. A SimCoupe change is stillneeded to return something for that read attempt. It would also be wiseto block attempts to write to sector 10, since it can't be saved.SiCheers! LCD