[Coco] large HD in OS9/68K

David Hazelton davehazelton at access-4-free.com
Thu Nov 13 21:04:00 EST 2003


Dave Kelly wrote:

> On Thursday 13 November 2003 02:44 pm, you wrote:
> 
> 
>>>My MM1 drive is set to 33 spt starting with sector 0. So that's 0 - 32.
> 
> Are you sure that the 33 is not hex. So that  should be 0 - 33 = 1 - 34.
> 
>>I wonder if there's any valid reason for starting with sector 0?  It's
>>apparently an odd setup.
> 
> 
> Zero is the first number.
> It is my understanding that machine language and the C language uses 0 as the 
> first number.  OS9 follows this convention.
> 
> Or am I getting this CRAFT virus that seems to be spreading across this 
> newsgroup.
> 
> Dave
> 
> 
I thought that Microware used the Universal disk format that started at 
track 0, sector 0 single density. but later modified this due to some 
Disk controllers could not do this, thus the Sector/Track offset in the 
descriptors.  Which I would believe those offsets would both be set at 1 
by default, so every controller could deal with it.  Maybe this was 
after done after the original MM1 version of the OS.  I have not looked 
at the settings on the AT306, but on a VME machine running V2.4 I did 
look at this as more of a confirmation of what I was reading.

~David Hazelton







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