[Coco] CoCo SDC Harddrive Mode

[Barry Nelson]

> Allen Huffman alsplace at pobox.com  <mailto:coco%40maltedmedia.com?Subject=Re%3A%20%5BCoco%5D%20CoCo%20SDC%20Harddrive%20Mode&In-Reply-To=%3C1E247ECE-0BCB-4540-BFF8-5C24BEDA6385%40pobox.com%3E>
> Wed Mar 29 11:07:04 EDT 2017
> 
> On Mar 28, 2017, at 10:33 PM, Dave Philipsen <dave at davebiz.com <https://pairlist5.pair.net/mailman/listinfo/coco>> wrote:
> > 
> > Allen Huffman has a nice write-up about getting NitrOS9 up and running on the CoCoSDC and it involves using an image file that is 'hard drive' size.  In fact, if my memory serves me correctly, it's pretty much done automatically when the CoCoSDC see a large image file.
> > 
> > Take a look here: https://subethasoftware.com/2015/02/02/manually-making-a-bootable-nitros9-hard-drive-image-part-1/ <https://subethasoftware.com/2015/02/02/manually-making-a-bootable-nitros9-hard-drive-image-part-1/>
> 
> Thanks for the plug, Dave!
> 
> My brute force way of moving the bootfile over to the image needs to be fixed. Cobbler and os9gen have some quirks with large images since they were only designed with floppy drives in mind.
> 
> Kwikgen supposedly does it, and if true, I need to update my instructions with using that.

The commands cobbler and os9gen work much better on images that are single sided and have 18 sectors per track. I use the format below with my CoCo SDC for the OS9 “hard disk", it has 20480 tracks:

LSN0 Information:
  Total sectors   :   368640
  Track size      :   18
  Bytes in bitmap :   46080
  Sectors/Cluster :   1
  Root dir sector :   181
  Disk owner      :   0.0  
  Disk attributes :   dsewrewr
  Disk ID         :   $73DF
  Disk format     :   $0 (48 TPI, Single Density, Single Sided)
  Sectors/track   :   18
  Boot sector     :   36483
  Bootfile size   :   31850
  Creation date   :   11/12/2015 22:26
  Disk name       :   NitrOS-9/6809 Level 2
  Bytes/Sector    :   256