[Coco] Nitr0S-9 question

L. Curtis Boyle curtisboyle at sasktel.net
Wed Aug 15 13:36:51 EDT 2007


On Tue, 14 Aug 2007 22:21:29 -0600, Robert Gault  
<robert.gault at worldnet.att.net> wrote:

> Becker, Gary wrote:
>> What I am saying is that OS9boot is being written correctly and the
>> hooks in LSN0 for this file (DD.BT and DD.BSZ) are correct. I am not
>> saying that these values are for the boot track.
>>  Also nothing is being written into the boot track and the boot track
>> bits in the bit map are unchanged. I believe this is the offending code
>> in os9gen.
>>           leax  sectbuff,u
>>          ldy   <lsn0+DD.MAP,u	get number of bytes in device's bitmap
>>          lda   <devpath
>>          os9   I$Read            lbcs  Bye
>>   If DD.MAP is greater than 1024 bytes, the read will overfill sectbuff.
>> This happens with a disk larger than 1024*8*DD.BIT*256 or 2Meg if DD.BIT
>> = 1. This is uncommon for floppies, bit not for hard disks.
>>  Someone must have run into this issue in the past.
>>
>
>   The value of DD.MAP for the default emulation hard drive is $B400,  
> many more sectors than 1024. The value for DD.BIT is $01. The result is  
> a large map which could be made more efficient on large drives by adding  
> code to permit Format to accept larger values of DD.BIT.
>   That doesn't address the issue of os9gen and hard drives. Why don't  
> you use the HDBDOS/RGBDOS system of placing the OS9 boot disk in a Disk  
> Basic partition further out on the hard drive. Then you can either  
> create 35track single sided boot disks and copy them to the hard drive  
> or modify hdrive or emudsk to create a new driver that can read a boot  
> disk in the Disk Basic portion of the hard drive. I've done this and it  
> works very well with the stock os9gen or cobbler.

Bruce Isted, for the Eliminator, created Kutil, butil, and I believe BtGen  
(or something like that) to handle and replace cobbler and os9gen. I never  
used os9gen on a hard drive., be it an Eliminator, B&B or Glenside IDE.  
Kutil was for the kernal track (he created it originally for the  
Eliminator's ability to partition single cylinders separately for multiple  
boot tracks, and you could just change the ptr on sector 0 to select which  
one was active... and since those tracks were separate partitions, you  
could (almost) never screw them up since you're regular hard drive access  
didn't know they existed. This is what gave me the idea for the partition  
offsets in my version of the Glenside IDE driver). Butil activated your  
OS9boot file to whichever one you wanted, similiar to kutil, except for  
the OS9Boot file.
    I usually used Gale Force's Kwikgen for bootfile building/modification,  
it is/was WAY faster to build and move things around (all done in RAM  
until the final write was done), and easier to use. One should get a hold  
of Wes Gale and see if he would be willing to release it for the Nitros9  
project - it worked for both stock and Nitros9. Maybe get Kwikzap (like  
DED, but with color and direct screen writes, and some other options)  
released as well.



-
L. Curtis Boyle



More information about the Coco mailing list