[Coco] [Color Computer] Re: setting up Nitros9 device descriptor for SCSI drive

[Gene Heskett]

On Thursday 14 September 2006 13:35, jlhickle wrote:
>Ah, and I was trying to have os9 start AFTER HDB-DOS.  I'll blame
>working late into the night for why it didn't occur to me that, if
>NitrOS-9 was at the end of the drive, the offset shouldn't be such a
>large number.
>
>I'm still not sure what to set the sectors per track at; the drive
>specs say "AVERAGE SECTORS PER TRACK = 107 rounded down".
>
The drive, I believe, expects an LSN as the address to seek to.  So it may 
be possible to just arbitrarily assign a spt value thats in that range.  

I'd choose a number thats easily divided for the trial, then set the size 
at some multiple of that which is just short of 524280 sectors, which is a 
full (65535 byte) FAT table*8.  That will allow 134,215,680 bytes of 
storage without going to multiple sector cluster setups. 524280 sectors 
divided by 102=5140 for the cyl value, and you have the full 134,215,680 
bytes available.  Thats decimal of course.  In hard drive 1024=1k speak, 
thats 131.070 megabytes. 

The next (/s1) descriptor could than start a new partition at LSN=524281, 
(cyl offset=5141) and repeat till out of drive or descriptors.

Theres probably a glaring error someplace above, but thats the general 
idea.

>Guess I'd better shrink that 3.9 Gigabyte os9 partition a bit ;)
>
>-jim
>
>> In general, NitrOS-9 works from the bottom of the drive and HDB-DOS
>> works from the top of the drive down. So in HDB-DOS you place an LSN
>> sector offset to the first drive, ie drive 0. NitrOS-9 only has to have
>> an entry only if you are using multiple NitrOS-9 partitions. The
>>
>>
>>
>>
>>
>> I don't recommend a NitrOS-9 partition >127MB because of this. 127MB is
>> HUGE!!!!!
>
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-- 
Cheers, Gene
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