From: "Fred Cisin (XenoSoft)"
<cisin(a)xenosoft.com>
Another minor gotcha: machines that used WDC179x disk controller chips
were capable of starting their first sector sooner after the index pulse
than those using NEC 765 series. Reading those with a 765 required
disabling ther index pulse.
Hi
I always wondered why some PC's didn't care if the drive had a
index hole or not to read the disk. It would care for formatting
but not for read/write.
Dwight