Re: How many variations of Dos 3.3 RWTS are there?

[BLuRry <brendan.robert@gmail.com>]

On Friday, March 15, 2013 3:45:37 AM UTC-5, gid...@sasktel.net wrote:
> On Thursday, March 14, 2013 1:28:39 PM UTC-6, BLuRry wrote:
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> > On Thursday, March 14, 2013 12:13:24 PM UTC-5, schmidtd wrote:
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> > > On 3/14/2013 12:51 PM, BLuRry wrote:
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> > > > I wonder, in order for disks to be normalized to DSK/DO and by extension PO formats, how many variations of RWTS actually exist?  It would be logical to assume the number is rather small since something running from a DSK implies it was already cracked to a 6-by-2 nibble format.
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> > > There were lots and lots of RWTS variants from third parties, ISVs, 
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> > > crackers, and pirates alike.  There were a few that came from Apple. 
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> > > All of the ones that don't have copy protection as their primary use 
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> > > case use similar entry points in memory and work on the exact same 
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> > > logical/physical structures on the disk itself.  To veer off that course 
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> > > made them incompatible with one another (which of course was the very 
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> > > point of copy protection).
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> > Yes, I get that but I was talking about the deprotected games that are stored in DOS-order (DO/DSK) images.  Those surely are not as varied I would imagine.  I am trying to see if there is a deterministic way of detecting an 6-by-2 RWTS in a more generic fashion than my previous attempt used in Apple Game Server.
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> It sounds like, Brendan, you are looking for different ways to decode the 6x2 and not so much the different RWTS routines.  Because the only real differences in the RWTS is, it still has 16 sectors per track, but some people found a way to program the RWTS to allow one to read more sectors per revolution of the disk.
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> Or am I misunderstanding?
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> Rob

No, I'm only interested in the standard track encoding -- what I'm trying to do is seek and modify all possible iterations of DOS 3.3 (or compatible) RWTS routines and replace them with serial-based transfer routines.  Some titles such as Fishies and Chipwits already work in Apple Game Server -- meaning you can boot these games without a disk drive via a serial cable.  Other titles however do not work because the RWTS entry points work a little differently so 'm trying to decipher them.

-B