Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!gem.mps.ohio-state.edu!ginosko!xanth!mcnc!rti!sunpix!matthew
From: matthew@sunpix.UUCP ( Sun Visualization Products)
Newsgroups: comp.sys.apple
Subject: Re: Rwts and the like...help!
Message-ID: <930@friar-taac.UUCP>
Date: 17 Oct 89 17:00:00 GMT
References: <8910160302.AA02096@trout.nosc.mil>
Reply-To: matthew@friar-taac.UUCP (Matthew Stier - Sun Visualization Products)
Organization: Sun Microsystems, RTP, NC
Lines: 44

In article <8910160302.AA02096@trout.nosc.mil> alank@pro-beagle.cts.com (Alan Krause) writes:
}
}  Ok, here's the situation:
}
}  I want to modify some things in ProDos 8's RWTS, so that when I format a
}disk, it will be 'different' than normal...  For example, I'd like to be able
}to change the address headers, epilog bytes, sector numbering, and the like.. 
}I do not have Beneath Apple ProDos (Unfortunately) so I cant refer to that...
}  My question is, how can I modify the RWTS in memory to do the above things,
}and then format a disk so that it contains this information?
}    Thanx,
}      Alan Krause
}      (@pro-beagle)

First off, the only internal ProDOS drivers are the Clock driver and the Disk ][
(5.25") driver, and the /RAM drive driver.

Secondly, the only device that support formatting is the /RAM driver. The Disk ][ 
driver only understands status, read and write calls (early versions of ProDOS8 
would do a write when a format call was requested, there by destroying the disk.
If this is fixed, I don't know.)

Third, if you REALLY need to do what your requesting, your going to have to write
a disk driver to read and write to you modified disk, so you might as well go all 
the way and write a complete driver to do all read/write/status/format requests.

Finally, Beneath Apple DOS and Beneath Apple ProDOS are invalueable tools for the
work ahead of you.  I'd try getting my hands on some copies.


(I once needed to include a DISK ][ formatter in a program I was writing.  I ended
up analyzing the DOS 3.3 RWTS code and optimized the heck out of the format routines.
If you really want to understand DISK ][ driver code, I'd suggest a good study of
the DOS 3.3 RWTS code.)





-- 
Matthew Lee Stier                            |
Sun Microsystems ---  RTP, NC  27709-3447    |     "Wisconsin   Escapee"
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