File: FILSIZ.RA of Tape: Various/ETH/fc-files

(Source file text) 

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	SECT8 FILSIZ	/FETCH SIZE OF SPECIFIED FILE
	BASE	0
	STARTD
	FLDA	0		/GET RETURN ADDRESS
	FSTA	ADCRET
	FADD	L2		/GET ADDR OF ARG POINTER
	FSTA	0
	FLDA%	0		/GET ADDR OF FILE NUMBER
	FSTA 0
	STARTF
	FLDA% 0
	JEQ  BADNR		/NUMBER <= 0
	FSUB  L9
	JGT  BADNR		/NUMBER>9
	FLDA%  0	/GET FILE NUMBER
	FMUL  L9		/9 ENTRIES PER DSRN NUMBER
	FADD DSRN
	ALN	0		/FIX IT
	FSTA	CHANEL		/STORE IT FOR FILE
	TRAP4	FILE		/GOTO TO PDP8 CODE 
	FLDA	FILNR
	FNORM			/GET THE SIZE AND NORMALIZE IT
	JGE ADCRET	/GUARD AGAINST NEG >4000
	FADD L4096
ADCRET,	JA	.
BADNR,	FCLA
	JA ADCRET	/RETURN WITH 0
L2,	0;2
L4096,	F 4096.
L9,	F	9.
DSRN,	F	2210.	/THIS IS TRICKY IT IS THE DSRN BASE ADRESS
/FROM FRTS IN DECIMAL -2
FILNR,	13;0;0
CHANEL,	0;0;0
FILE,	0	/FETCH THE FILE SIZE
	CDF 0
	TAD% CHANEL+2		/POINTER TO REQUIRED SIZE
	DCA FILNR+1
	CIF 0
	JMP% FILE

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