[Coco] Glenside IDE booting problems

[Don Johnson]

On 2010-12-03, at 8:41 PM, Willard Goosey wrote:

> On Fri, Dec 03, 2010 at 12:12:47PM -0800, Don Johnson wrote:
> 
>> Any suggestions on how I can modify the device descriptor?
> 
> You can use ezgen, but since it doesn't automaticly decode descriptor
> modules:
> name   offset size (bytes)
> IT.CYL  $17     2	Number of cylinders
> IT.SID  $19     1	number of sides (heads)
> IT.SCT  $1B     2	sectors/track
> IT.TOS  $1D	2	sectors/track on track 0
> IT.SAS  $20     1	number of sectors allocated at a time
> 
Okay, so the EZGen manual clearly states that to change a value in the module I can use the 'c' command like this;

"c x z, w	Change value of byte at offset 'x' in current module to 'z', and change value of byte at offset 'x+1' in the current module to 'w' "

or "c x z" for only one byte updated.

So I load up the OS9Boot file and link the H0 device descriptor.  I then run these commands without complaint from ezgen (believe me I tried a number of commands that it complained about)

c 17 40, 74		# set the cylinder count to 16500
c 19 10			# set the head count to 16
c 1B 00, 3F		# set the sectors / track to 32

I then correct the CRC and header parity with a 'v' command and quit.  EZGen saves the work directly to the OS9Boot file.  I reboot and I still get the same problem of the booting process failing if the hard drive is turned on.

So, first of all anybody think I used the wrong byte values?  Second, those cylinder/head/sector numbers were the values from the hard drive after I formatted it, but the original (physical) values were 8940/15/63 according to the detect_ide.b09 script I ran from the Glenside disk, and these new values, the ones I used, where listed as the logical current values.   Should the device descriptor have the physical or the logical values?


Of course this whole issue of resetting the device descriptor may not be relevant anyways because I seem to be able to use the hard drive as long as it is not powered up when I boot up.  This is only true if I have the interface plugged directly into my CoCo3 and not into a multipak.  I have yet to make any scenario work if the interface is plugged into the multipak, regardless of which address I am using for the interface, or whether the hard drive is turned on or not.

-Don



> Willard
> -- 
> Willard Goosey  goosey at sdc.org
> Socorro, New Mexico, USA
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