[Coco] EZGen on NitrOS9 level 1

[Gene Heskett]

On Saturday 24 November 2012 09:35:49 Chester A Patterson did opine:

> Hi. Level 1 OS9Boot has 4 "lost" bytes that are not part of any OS9
> module tacked onto the end of one of the bona fide modules, I don't
> recall now if REL or BOOT or which exactly. What they are I do not
> know, but they are needed. If you make a new bootfile, EZGen will not
> add those bytes and OS9 L.1.xx will not boot. If all you do is edit
> modules, there may be safer (and easier) ways, like DED. If you plan on
> replacing entire modules, be careful. Replace them ONLY from disk
> files, not RAM! I personally love EZGen's versatility but for L1 you
> gotta watch out for those 4 bytes.
> 
This could be something that my 'vfy' can handle, particularly since you 
are dealing not with the os9boot file, but with the contents of the 
boottrack itself.

There is extra data on each end of the track 34 image.  If a directory 
entry is constucted for the boottrack so that it is no longer hidden from 
view, then vfy -sk will split that track into its 5 parts as seperate 
files.  Work in an empty directory so they don't get lost in the noise.  
And, once that directory name has been made with KRNL_to_DIR, DON'T EVER 
DELETE IT as that will also free the boottrack area of the disk for other 
uses.

It can however make it easy to generate a new boottrack by opening it for 
update in basic09, and writing a newly merged, must be $1200 bytes long, 
'bttemp' file to it.

Back to vfy -sk

The first file generated will be the header bytes that identify it as OS 
(two bytes) its size and execution address (4 bytes) then the three modules 
will be identified and saved as separate files.  Anything left over, which 
is actually the IRQ jump table, will then be saved as the filler data.

You can, because the 3 modules in the middle are padded to be a fixed size, 
write a merge list that could have the boot module that boots from a 
floppy, replaced by a boot module that boots from a hard drive for 
instance.  Or the os9p1 module could be replaced with a newer one but be 
aware that the os9p2, because some functions have been moved from one to 
the other to balance the os9p1 used space, that the corresponding os9p2 
build would have to be used in the OS9Boot.  Since rel also has a 
simplified screen driver, I've not tried to ever change that on an L1 
system.

ISTR I wrote a utility that made that boottrack directory entry way back in 
the mists of time.  I haven't used it in yonks, I hope its not been lost, 
but that can also be done with dEd.  Yup, found it, I'll put a copy in 
Genes-os9-stf of my web page shortly.  It is called KRNL_to_DIR.  The .B09 
version is loadable into basic09, the plain version is packed b09 code and 
if your runb doesn't have the usual utils attached, it may not run.  The 
runb I used back in the day had inkey, syscall, and gfx2 merged to it.  So 
I also put that 'runb' on that page, but ISTR there is a patch, a 1 byter 
IIRC, that has not been done to that runb that I can recall doing, and I 
don't believe its a show stopper.

> -----Original Message-----
> From: Bill Pierce [mailto:ooogalapasooo at aol.com]
> Sent: Friday, November 23, 2012 5:23 PM
> To: coco at maltedmedia.com
> Subject: [Coco] EZGen on NitrOS9 level 1
> 
> 
> Hi Guys,
> Is it safe to run EZGen from a level 2 system to work on a level 1
> bootfile? I'm trying to build a special level 1 v2 boot and would like
> to use EZGen. I just don't whether it will mess up the level 1
> bootfile.
 
Ezgen should work on the bootfile, but not on the boottrack Bill.  Disks 
that don't have enough contiguous free space to construct a copy of the 
modified OS9Boot file are its major problem.  You can make it throw a non-
destructive error a lot faster by using dmode to set the sas of that drive 
to about 98 before sending ezgen into the lions den. That will make it 
search for a bit less than 40k of contiguous space, and when it can't 
allocate that much it will bail out before any damage has been done.

> Any help appreciated

I hope this helps.

> Bill P
> 
> Music from the Tandy/Radio Shack Color Computer 2 & 3
> https://sites.google.com/site/dabarnstudio/
> Bill Pierce
> ooogalapasooo at aol.com
> 
> 
> 
> 
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Cheers, Gene
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