DiskFace USING [Label, PageNumber, Type],

PrincOps USING [GlobalFrameHandle, PsbIndex, PsbNull, StateVector, SVPointer],

Basics USING [BITXOR, HighHalf, LowHalf];

IMPORTS Basics =

(this is the actual usage of PrincOps.PDA.available.)

availableA: UNSPECIFIED,

externalStateVector: LONG POINTER TO ExternalStateVector,

availableB: ARRAY [0..2) OF UNSPECIFIED ];

state: SVPointer, -- client's higher level state. (a short pointer

reason: SwapReason,

level: [0..3777B],

parameter: POINTER TO DebugParameter,

versionident: CARDINAL,

loadstatepage: CARDINAL,

spare: CARDINAL,

vmRunTable: LONG POINTER TO VMRunTable,

mds: CARDINAL, -- MDS of *all* processes.

filler: [0..100B) ← 0,

psb: PrincOps.PsbIndex ← PrincOps.PsbNull, -- PrincOps of current process.

fill: ARRAY [10..19) OF WORD];

handled by user's nub

proceed(0), -- THIS MUST BE FIRST !!

start(1),

call(2),

resume(3),

quit(4),

showscreen(5),

kill(6),

handled by debugger

breakpoint(8),

worrybreak(9),

worrycall(10),

uncaughtsignal(11),

explicitcall(12),

return(13),

returnAborted(24),

(31)

};

spare: POINTER,

body: SELECT OVERLAID SwapReason FROM

nRuns: CARDINAL,

runs: SEQUENCE length: CARDINAL OF Run];

page: INT -- VM.PageNumber--,

count: CARDINAL, -- number of pages in this contiguous run --

Description of the first page of the run:

deviceType: DiskFace.Type,

deviceOrdinal: CARDINAL,

diskPage: DiskFace.PageNumber, -- physical page number relative to [type,ordinal]

labelCheck: CARDINAL -- compact approximation to the label of first page of run

];

BEGIN

OPEN fID: LOOPHOLE[label.fileID, MACHINE DEPENDENT RECORD[a,b,c,d,e: CARDINAL]];

adj: INT = label.filePage - offset;

RETURN[ Basics.BITXOR[

END;