Loading ...
Sorry, an error occurred while loading the content.

26231Re: Booting a NorthStar Horizon

Expand Messages
  • s100doctor
    Jun 13, 2012
      "wb4jfi" <wb4jfi@...> wrote:
      > Herb:
      > I will contact you separately as well, but I can report that I have very successfully punched both 5-1/4 N* and regular 8-inch CP/M floppy disks and used both sides (single density). There were brands that this was a good practice with, and brands that were bad. Memorex were bad, 3M and Verbatim were OK, for example.
      > One issue was that you needed to make sure that the felt pad opposite the head was clean and in good shape. Otherwise, you ended up with scratches which did not affect the "main" side, but could cause severe problems when flipped to the head.
      > Kyle

      Kyle contacted me, and we discussed what he's talking about. Turns out, he's talking about "flippy disk" technology. In the old OLD days, floppy drives were single sided. But most diskettes and all double-sided disks, have magnetic coatings on BOTH sides of the "cookie". Punching a hole through the ENVELOPE on the "opposite side" where the index hole is punched, lets you "flip" the disk over and use either side on a single sided drive. On a double sided drive this is moot.

      What is in discussion in this thread, is 10-sector HARD SECTORED diskettes. The holes are sector holes in the "cookie", not a access hole in the envelope. Very different. Now I have to add "flippy disks" to my online collection of floppy information; another "lost art" of 20th century computing.

      Herb Johnson
    • Show all 21 messages in this topic