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- Newsgroups: comp.sys.apple2
- Path: sparky!uunet!munnari.oz.au!labtam!labtam!philip
- From: philip@labtam.labtam.oz.au (Philip Stephens)
- Subject: Re: Apple II RWTS codes.
- Organization: Labtam Australia Pty. Ltd., Melbourne, Australia
- Date: Thu, 27 Aug 1992 22:55:59 GMT
- Message-ID: <philip.714956159@labtam>
- References: <1992Aug25.073024.13293@ausom.oz.au> <1992Aug26.112324.6256@iscsvax.uni.edu> <philip.714873752@labtam> <1992Aug27.062300.4071@ee.rochester.edu>
- Lines: 17
-
- David Seah writes:
-
- >I was under the impression that the Locksmith fast 16 sector copier didn't do
- >any denibblizing of the raw disk data...
-
- In fact, it does! I disassembled the code once, and was quite amazed to see
- that it performed both read and write conversions on the fly. I don't remember
- the full details now, but when reading it converts the 6-and-2 encoding back
- into 256 bytes of data that is still partially encoded, but which can then be
- converted back into 6-and-2 encoding on the fly. Pretty interesting stuff.
- The upshot of which is that Locksmith can read many more sectors into
- available memory than it could if it did not denibblize the raw data. The
- authors of Locksmith were obviously very clever programmers.
-
- Philip Stephens
- Labtam Australia Pty Ldt
- philip@labtam.labtam.oz.au
-