[Coco] Glenside IDE booting problems

Robert Gault robert.gault at att.net
Fri Dec 3 19:53:02 EST 2010


Don Johnson wrote:

>
> Okay, latest update.  The new System Disk I created with the Hard Disk modules installed will boot up only if the Hard Drive is turned off during boot up.  I find this to be weird considering everything in the Glenside Documentation suggested that it needed to be on during boot up or else if would fail.  To add to the weirdness if I turn the hard drive on after the boot up process has completed I can still access the hard drive at /h0.
>
>
>> Any suggestions on how I can modify the device descriptor?
>>
>>
>> -Don

Well so far so good. You have found the cause of the boot failure to be the 
order of modules in OS9Boot. You almost have correct access to the hard drive. 
Now you need to be sure that H0 matches the hardware capabilities of your hard 
drive.

Gene mentioned the program dmode. I'm not sure that is part of the stock OS-9 
Level II package but probably anyone on this list can send you a copy by email. 
Dmode can alter the parameters of H0 and Cobbler will then save the changes to 
your OS9Boot file: dmode /h0     cobbler /h0
The problem will be knowing how to change H0. Here is a dmode output for a 
virtual hard drive used with MESS and VCC.

dmode /h0
nam=H0 mgr=RBF ddr=EmuDsk
hpn=07 hpa=ff80 drv=00 stp=00 typ=80 dns=01 cyl=005A sid=40
vfy=01 sct=0040 t0s=0040 ilv=03 sas=20 wpc= ofs= rwc=

There are several parameters crucial for correct hard drive operation, cyl 
(number of tracks per head/platter) sid (number of heads/platters) sct & t0s 
(sectors per track) sas (minimum number of sectors allocated at one time).
If you don't have a program that can read this information from the hard drive, 
you need written documentation. Go to the manufacturer's web site if you don't 
have the info. Tell us the specs of your drive.

OS-9 also has an issue with an allocation table where the system keeps track of 
free and used disk space. By default each bit in the map represents one sector 
which is fine for a floppy but won't work for a large hard drive as the map 
either can't get large enough or would be a great waste of space.
LSN0 (first sector on any disk/drive) has DD.BIT as a 2-byte entry at $06 
(base-0). This indicates how many sectors are represented by each bit in the 
allocation map. The value is 2^n or 1, 2, 4, 8, 16, etc.
Probably a good starting value for a hard drive would be at least 8 for DD.BIT 
but you can try 1. Unfortunately the stock Format module does not permit 
changing DD.BIT. I believe the NitrOS-9 format will accept a different value 
(cluster size).
Anyway this is not an immediate issue but one you may want to pursue after you 
get proper hard drive access.

There is a program dEd which will permit you to examine byte by byte the 
contents of LSN0 on your hard drive ( or any other sector);  ded /h0@  . It 
would be very helpful if you could post both the dmode and ded data for your H0.

Without more information, I can't think of good things to try.



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