Osborne-1 SD format

From: Randy McLaughlin <cctalk_at_randy482.com>
Date: Mon Feb 21 15:28:11 2005

From: "Dave Dunfield" <dave04a_at_dunfield.com>
Sent: Monday, February 21, 2005 12:38 PM
> Hi Dwight,
> In my original posting, DD means "360k" - I've been testing with both
> kinds of drives.
> It's interesting with the Cromemco CDOS disk - the DD area is formatted
> to 10 512 byte sectors/track, and in the DD(360k) drive, I can't read
> them at all - For this test, I pulled the actual Teac drive that I have
> been using on the System-3 (which reads it fine) - it looks like the PC
> controller has touble with the tightly spaced sectors.
> It (the DD drive) can however read all of the SD sectors in track-0
> just fine!
> The HD drive reads the entire disk perfectly, EXCEPT for Sector-1 of
> Track-0 (the SD track) - it quite reliably refuses to read the first
> sector of the SD track. The remaining sectors of the SD track and all
> of the DD tracks read OK.
> So - I can read the entire disk, however I have to do it on two separate
> drives - Unless I can reliably resolve these problems, I think I will
> make an option in my disk imager to merge images read of different
> drives - In some cases (like this one), it may allow a complete image
> to be constructed where it otherwise might not be.
> The :-( for the day is that it appears that NONE of the PC controllers
> that I have will format a single-density track - I can recreate the DD
> tracks just fine (Even with 10 sectors/track), but so far no joy on
> formatting and writing that SD system track.
> Regards,
> Dave
> --
> dave04a (at) Dave Dunfield
> dunfield (dot) Firmware development services & tools: www.dunfield.com
> com Collector of vintage computing equipment:
> http://www.parse.com/~ddunfield/museum/index.html


I found it easy to use 3.5" drives (DD media or HD media with media hole
taped over).

Luckily I have a 3.5" drives with DS jumpers but a modified PC cable works
just fine.

Received on Mon Feb 21 2005 - 15:28:11 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:37:39 BST