User`s guide

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012- What does it mean to "Boot" a disk?
BOOT comes from the idea of 'pulling yourself up by your bootstraps'. The
Apple II disk controller ROM has just enough smarts to load-in DOS's Bootstrap
Loader from Track 0, Sector 0 (it comes in at address $800 ...).
The Loader loads in a still smarter, bigger routine from several sectors of
Track 0. This routine is the one which loads in the rest of DOS, moves it to the
proper place in memory, and ends up going to DOS's Cold Start routine. Finally,
the hello program is loaded and executed.
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013- What file types does DOS 3.3 have and how is file
type information saved in the Catalog?
In a DOS 3.3 Catalog sector, the third byte in each file's entry tells the
type of the file:
Byte Value* File Type
00 Text
01 Integer BASIC
02 AppleSoft BASIC
04 Binary
08 S type
10 R: Relocatable object module
20 new A type
40 new B type
*DOS 3.3 sets bit 7 of the byte if the file is locked. (e.g. 84 --> a locked
Binary file)
Type R files show up in just a few applications. An R file begins with 6
bytes which a "loader" routine can use to tell the Target location of file
contents, How many bytes to move, and Source location to move from.
Although S, new A, and new B are included, no official application was
defined for them and no DOS commands were created to make any special use of
these files.
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from David Empson
There was an "R" type relocating loader included with the toolkit for use
with BASIC programs and relocatable routines being loaded into upper memory.
"S" was used by some programs for a generic image file, or something that was
not likely to be touchable with normal code.
The LISA assembler used the second "B" type for its source files. It had a
patched version of DOS that changed the file type list to read "LARSBAIT", so