On 07/28/2011 03:21 AM, lynchaj wrote:
It is always a signal from the drive to the controller. It used to be defined as RDY, but was later designated as /DSKCHG, meaning the drive door had been opened; hence the disk has possibly been changed and all cached information should be invalidated.Hi! As I understand it, the floppy drive interface pin 34 can be either an input or an output depending on the drive. --John Older drives used READY as an output to tell the controller the drive was ready. Other newer drives use DSKCHNG as an input for when the controller tells the drive to eject media. It is one of the many issues which makes floppy drive controllers difficult to design. Thanks and have a nice day! Andrew Lynch On Jul 28, 5:54 am, Douglas Goodall <dougla...@mac.com> wrote:The disk change line was a signal from the drive to the operating system that the media may have been changed since the door had been opened. In CP/M, this would trigger a "drive reset" invalidating the allocation vector. (kind of like a control-c) Douglas On Jul 27, 2011, at 11:51 PM, Sergey wrote:Hi,Can some please enlighten me about the purpose of pin 34 of floppy interface? This pin is named "Disk Change" on newer drives, and apparently it was "Ready" on older drives. In both cases it is an output (from floppy to FDC). But the default setting of DiskIO board uses it as an input to floppy (controlled by bit 7 of the latch), which presumably would allow ejecting the disk by sending "Disk Change". I guess it is just an incorrect interpretation of the "Disk Change"... it actually means that media was changed since the last operation. But maybe I am mistaken...Thanks, Sergey-- You received this message because you are subscribed to the Google Groups "N8VEM" group. To post to this group, send email to n8...@googlegroups.com. To unsubscribe from this group, send email to n8vem+un...@googlegroups.com. For more options, visit this group athttp://groups.google.com/group/n8vem?hl=en.---  ‎//* * \\ (/(_•_)\) _/''*''\_ (/_)^(_\) Douglas Goodall douglas_good...@me.comhttp://www.goodall.comhttp://www.linkedin.com/in/douglasgoodall "Did Goloka think the Ulus were too ugly to save?"- Hide quoted text - - Show quoted text - |