5 1/4" hard-sectored disk..

From: Dwight K. Elvey <dwight.elvey_at_amd.com>
Date: Thu Oct 21 16:13:29 2004

Hi Jim
 It might be a good idea to check the clock rate of the
data from the disk. If it is that standard 2 uS, per pulse,
one can read it with most any hard sectored controller.
( Heathkit H89 comes to mind )
 Getting the data from the disk is the first step. Most
everything after that is just choice of implementation.
Dwight

>From: "Jim Donoghue" <jim_at_smithy.com>
>
>I have some 5 1/4" hard-sectored disks that contain CPU microcode. They
>aren't 'formatted' with a filesystem, but are read with a simple board
>that contains some 9602's, a shift register, and a Z80. A dilemma:
>should I try to intercept the data from the board, write it to flash
>memory, and build a board to replace the whole Z80/hard-sectored disk
>thing, *or* try to build something to write the data stream out to
>another 5 1/4" disk. The Z80 doesn't care about the sector pulses - only
>the index pulse. So I could get away with a standard floppy instead of a
>hard-sectored one.
>
>The disk thing would allow me to keep using the original hardware, which
>would be nice, but I don't know the first thing about attempting to
>write the data stream back to the disk.
>
>I have no backups of the microcode disk, and no way to replace it when
>it dies. Every time I fire the thing up I feel I'm getting a little
>closer to it's death...
>
>Jim
>
>
>
Received on Thu Oct 21 2004 - 16:13:29 BST