Hi Folks,
I'm having difficulty in being able to read my double sided 720K msx formatted discs on PC or mac.
However it reads fine on the MSX itself. I used _FORMAT in the msx basic screen and also successfully saved an read a small file.
Any ideas why this won't work on the PC or MAC? (Both seem to support FAT12, which i assume msx discs are).
Windows does not read fat12. not native. if you wanna read msx disks on a pc easy way is using linux. but 360k disks in a hd drive is somtimes read only. it says it can write but will do it ad 720k
I'm not sure if the issue is related but in old days when MSX disk formatted from BASIC with CALL FORMAT needs to be read under MS-DOS on IBM compatible computers, we were changing one byte in boot sector and after that you could use in on both computers. Don't remember any details on the byte position and values though...
Other issue is that modern drives often don't support 720K format at hardware level.
The Drive I'm using on PC/MAC is BXXU0130 - IOmega Floppy drive which can read/write both 1.44MB and 720K discs.
The original drive in MSX I'm using supports 720K double sided.
It appears PC/MAC and MSX machines can create their 720K FAT12 discs but each have trouble reading the other despite having formatted in FAT12 and 720K, thinking there might be a subtle difference.
I'm curious re the boot sector. would this affect readability or just affect whether or not we can boot the machine from the disk?
Maybe your drive driver is no longer supported by your systems. A generic driver controls the drive instead and it doesn't support 2DD. Try your drive on an older system with Virtual Box.
I'm curious re the boot sector. would this affect readability or just affect whether or not we can boot the machine from the disk?
I don't remember much, i googled a little to maybe refresh some memories and i think it was the byte with offset $15 (0x15, &h15, etc) aka media descriptor byte, i think that MSX just used it differently (for clarity - computer was YIS805R/128) and the value which were at this byte if formatted by MSX was misunderstood by DOS 5.x making disk unreadable, so i'm not sure if that is really revelant for moder OS-es...
I tried to find the disk which appeared to have formatted to 720K, turns out its probably a quirk of the disk manager software I'm using which seemingly writes as normal 2HD but sets the capacity to what it wants, in this case its a 730K capacity with an unusual 49.7MB available, which is clearly not possible. I used the iomega usb-floppy BXXU0130 (windows citizen floppy disk driver installed).
So to clarify to create a 720KB formatted disk, I need to run the FORMAT A: /N:9 /S: 80 in the command line on windows based systems, this doesn't work for my usb-drive but does work for an old PC with built in drive. I believe it will work for later versions of windows provided the drive is built in and the disk controller chip has the ability.
I assume that the usb-drive has no way of reading 720KB disks either, based on the fact its having trouble with msx formatted disk.
