Google
 

Trailing-Edge - PDP-10 Archives - bb-jr93g-bb - 7,6/ap017/forio.c17
There are 10 other files named forio.c17 in the archive. Click here to see a list.
 REP 3/1	;17C1
		TV	FORIO	I/O ROUTINES,11(5014)
 WIT
		TV	FORIO	I/O ROUTINES,11(5033)
 INS 897/2	;17C2
	***** End V11 Development *****

	5031	MRB	9-Mar-87
		When using random files and the record number is such that
		when the page number is calculated (in routine RMAPW) it
		exceeds 512*512 pages (the operating system limit), give 
		an error message.

	5033	MRB	18-Mar-87
		Correction to edit 5031. When using RMS files WSIZ(D) may
		1)not be set-up yet or 2)will be set to the record size.
		In either case we will need to calc the number of bytes
		in a file page ourselves. (routine RMAPW)

 INS 31/47	;17C3

 REP 35/47	;17C4
		SUBI	T1,1		;GET # RECS BEFORE THIS ONE
		MOVEM	T1,CREC(D)	;STORE PREVIOUS RECORD NUMBER
		IMUL	T1,T2		;GET # BYTES BEFORE THIS ONE
		MOVEM	T1,BYTN(D)	;WHICH IS THE BYTE NUMBER OF REC BEG
		POPJ	P,
 WIT

		SUBI	T1,1		;GET # RECS BEFORE THIS ONE
		MOVEM	T1,CREC(D)	;STORE PREVIOUS RECORD NUMBER

		IMUL	T1,T2		;GET # BYTES BEFORE THIS ONE
		MOVEM	T1,BYTN(D)	;WHICH IS THE BYTE NUMBER OF REC BEG 
	;
	; [5031] Calculate the number of the file page where this record will end.
	;	 Check to see if the it is greater than the max page number (2^18)-1.
	;
		ADD	T2,T1		;[5031]#Bytes_in_rec + File_byte#  
		SKIPN	T1,BPW(D)	;[5033]Get number of bytes/word
		 POPJ	P,		;[5033]BPW(D) not set-up, Skip this test
		LSH	T1,^D9		;[5033]Calc number of bytes/file page
		IDIV	T2,T1		;[5033]Calc file page number
		MOVE	T1,@A.REC	;[5031]Get Rec# (for err message)
		CAILE	T2,777777	;[5031]Is this past the max page number?
		 $ACALL	IRN		;[5031]Yes "illegal record number"
		POPJ	P,		;[5031]No, it's ok!

 SUM 97599