[Coco] Drive info

Bruce W. Calkins brucewcalkins at charter.net
Fri Sep 6 21:43:13 EDT 2013



----- Original Message ----- 

From: "Bill"

> Isn't there a way I can check a set of drives to see if they are 35 or 40
> track, single or double sided. Some kind of PEEK or POKE?
>
> Thanks



=============================



There were very few 35 track drives packaged for use with the CoCo.  There 
were none or close to none 35 track half height drives.


Extended Color Disk Basic (ECDB) does not support 40 tracks and will trash 
the extra tracks should it encounter one.  You WILL need to keep your 40 
disks away from a normal ECDB system.


This is not an issue with OS-9/Nitros9 as the description of the individual 
disk is on the disk.  The descriptor in the booted OS-9/Nitros9 however must 
support the disk's described size or larger.  That means that you can read 
and write a 35 track disk on a system set up for 40 track disks, but not 
read a 40 track disk on a system using a 35 track descriptor.  Formatting a 
disk as 40 tracks with OS-9/Nitros9 would, after much clicking, return an 
error in the rare cases where one actually has a 35 track drive.  The 
descriptor is loaded during the boot process, and can be changed on the fly.


Single or double sided; open it up and look for cables to the heads on both 
sides, or look up the model number for the specifications.


Bruce W.




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