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View Full Version : Kodak 5.25" drives -- QNX had a driver for it



krebizfan
February 1st, 2012, 09:19 PM
Several years ago, there were several threads regarding the higher capacity (about 3MB) Kodak 5.25" disks. While looking for other things, I happened on a link to a 1985 driver for handling these drives. It probably isn't too much interest but increased my knowledge about the drive. So I'm placing this post here and if someone else comes looking maybe finding that driver might help a little.

ftp://ftp.qnx.com/usr/free2/disk/drivers/kodak.c

Chuck(G)
February 1st, 2012, 09:42 PM
Interesting--I've got the 3 and 6MB drives, along with a couple of blank preformatted floppies for them.

The 3MB drives were used in the Kaypro Robie.

There's not much special about the controller--it's basically a high-density controller (before high-density PC controllers were available). Most of the smarts are on the drive (usues a Moto 68xxx MCU). The Kodak/Drivetek (Kodak bought them after Drivetek went bankrupt) drives have a standard 34-line floppy interface. It spins 360K floppies at double speed and the special high-density floppies at normal speed and packs the tracks at 192tpi.

The 3MB drives use a two-stepper positioner--one stepper turns the leadscrew and is the "coarse" positioner; the other uses a cam-and-lever arrangement to get "fine" positioning. The high-density floppies themselves use an embedded servo scheme. You had to buy preformatted floppies--you could not format blanks yourself.