// ISF.D -- definitions for ISF and ISFINIT
// Copyright Xerox Corporation 1979

// last modified by Butterfield, March 9, 1979  1:01 PM

	get "altofilesys.d"
	get "disks.d"

structure FM0:	// filemap structure prefix
[	fp @FP	// fp for file
	DAs word 3 =	// first 3 page DAs
	 [ DA0 word
	   DA1 word
	   DA2 word
	 ]
	seal word	// for checking map
	disk word	// points to DSK structure for file
	zone word	// allocation zone for temporary page buffers
	last word	// index of last word (a da)
	end word	// index of end of available space
	onern word	// last rn added
	oneda word	// corresponding da
	rewrite bit	// if true, rewrite index
	blank bit 7
	extendmap byte	// extend map in zone by this amount
	extend word	// extend file in chunks of this many pages
	fmap word	// point this elsewhere to extend the map
]
structure FM:	// full filemap structure
[	@FM0
	blank word (size FM0/16)&1	// padding to ensure map is even
	map word 0	// beginning of map
]
manifest mapoffset = (offset FM.map)/16
manifest checksize = (offset FM.seal)/16+1  //number of leading words to check
manifest lenMapEntry = 2

manifest
[	ppc = 10		// max pages per BFS call
	version = 3 lshift 12 + 9 lshift 7 + 79	// month, day, year
]