![]() ![]() A 1.44M disk has a different magnetic surface to a 720K disk, and if you want to push out 1.44M of data you have to write it to a 1.44M disk. But then I read several posts online where people say they have done it. The presense or absense of the second hole determines the magnetic strength used by the drive head. 20 Ive read many times that USB floppy drives will not format (or read/write) 720K disks. The BBC cannot push data out fast enough to write 1.44M data (though there have been successes with hardware tinkering and self-interupting interupt routines - there was a detailed thread some years ago with loads of fancy cycle counting and osciloscope traces). It is the floppy controller in the computer that determines the data rate, not the drive. What about the drive itself does this need to be an early 720k PC drive or will a 1.44MB drive work (but just with DD disks)?Ī 3.5" drive is a 3.5" drive is a 3.5" drive. Please excuse the dumb question, so we can only use DD/blue 3.5" disks. They *MUST* be DD/blue/single-hole disks. two second wait, the loop terminates and returns a general error which is returned by the floppy handler as CF=1, AH=80h, ' Drive timed out, assumed not ready'.As per comments above, you *CANNOT* use HD/black/two-hole disks with 8-bit Acorn machines. If there is no FD interrupt within the ca. Good or bad, either way (CF=0 if good, or CF=1 when bad). When the interrupt occures, the interrupt routine sets the flag, which again breaks the wait loop. If youre formatting a floppy disc, ensure that it is formatted and not write-protected before you insert it into. The only interrupts possible here hit when the drive has found the desired track (or track 0). Click Menu over the disc icon on the icon bar. Whenever a Seek or Recalibrate/Reset is issued, the 8088 goes into an active wait loop, looking for a flag which is set whenever a disk interrupt occures. My bet would be on a missing track 0 signal. ![]() So I say the FDC doesn't return from whatever command (usually Seek) is issued. INT 13h timeout ( 80h) occures whenever the 'Wait for Interrupt' BOIS routine doesn't detect an interrupt within 2 seconds. ( Caveat: The following information is strictly only true for the XT BIOS, not 100% sure about the XT286, but I'd say it is as compatible here as the AT is) Conclusion from above messages: ![]()
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