[Coco] Re: problem with New NitrOS9

[John Donaldson]

Rodney,
   Your right. I forgot that the images are for real drives. What if I 
set up the disks as for a real coco3
and then set /d0 /dd to be the a: drive, which is a 80 track 3 inch. 
Would it boot from that??
    That is the other problem I am having with JC's emulator, I can not 
get eithr the 3 inch or the 5.25 inch 360K drive to read. All I get is 
Error #247 - Seek error. They both work under MSDOS and
with JC's DSKINI command.

John Donaldson


Rodney V Hamilton wrote:

>In article <40E88EEC.2090907 at charter.net>, 
>jadonaldson at charter.net says...
>  
>
>>  I just downloaded the lastest and greatest NitrOS9, dated May, 2004. 
>>I copied the
>>DSK's over to John's emulator, told it to use Dsik in drive 0 and Disk 2 
>>in drive 2. Rebooted
>>the emulator and the boot failed.
>>
>>What did I do wrong??
>>
>>John Donaldson
>>    
>>
>
>The NitrOS-9 distribution no longer supplies single-sided boot disk
>images, nor the front-side-only and back-side-only disk images that
>the JV and JC emulators both used to emulate double-sided boot disks.
>So how did you produce your /D0 and /D2 images?  The "ds40_[12].dsk"
>images are double-sided 40Trk disk images, used to create real disks.
>
>Actually, I find it very useful to patch the 720K 80Trk disk image
>to use as my /D0, with no /d2 needed.  If you look at the LSN0 byte
>at offset $0010 in the disk image, it will be set to $07 to indicate
>a double-sided 80trk disk, but if you CHANGE that byte to $06, the
>JV and JC emulators will be fooled into treating it as a single-sided
>disk with no need to split it into /d0 and /d2 pieces!
>
>However, the boot track will now be mapped to logical track #68 rather
>than #34 as the DOS command expects.  There are two solutions:
>
>[1] poke the new starting track number into the DOS command every time
>     eg:  POKE &HDF1C,68:DOS
>
>[2] patch the DOS command in the RSDOS rom image to automatically try
>    to boot from track #68 if the default track #34 fails
>
>If you use Jeff Vavasour's OS9BOOT instead of the BASIC ROM images,
>that can also be patched to auto-try tracks 34 and 68.  I posted both
>patches to this list on Oct 26 2003, (message ~#500 or so on GMANE or
>get it from the online maltedmedia COCO archives.)
>
>I hope this helps.
>
>  
>