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CPM OPERATING SYSTEMS/CPM 68K/1.0X SOURCES/v101/klib/blkio.c

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+/****************************************************************************/
+/*									    */
+/*			   _ b l k i o   F u n c t i o n		    */
+/*			   -----------------------------		    */
+/*									    */
+/*	The _blkio function is used to read / write a set of contiguous	    */
+/*	sectors in an open file.					    */
+/*									    */
+/*	Calling Sequence:						    */
+/*									    */
+/*		ret = _blkio(ccb,sector,buffer,count,bdosfunc);		    */
+/*									    */
+/*	Where:								    */
+/*		ccb	-> the open file channel control block		    */
+/*		sector	=  The desired starting sector number		    */
+/*		buffer  =  The memory address to begin transfer		    */
+/*		count	=  the number of sectors to read/write		    */
+/*		bdosfunc=  The BDOS function number (B_READ / B_WRITE)	    */
+/*									    */
+/*									    */
+/****************************************************************************/
+#include	"stdio.h"
+#include	"cpm.h"
+LONG	_blkio(ccb,sector,buffer,count,bdosfunc)
+						/****************************/
+	REG  FILE	*ccb;			/* open file pointer	    */
+	REG  LONG	sector;			/* Sector number	    */
+	REG  BYTE	*buffer;		/* User's buffer area	    */
+	REG  LONG	count;			/* # of sectors to do	    */
+	REG  int	bdosfunc;		/* BDOS function to use	    */
+						/****************************/
+
+{						/****************************/
+	REG  WORD	temp;			/* Temp return from BDOS    */
+	REG  LONG	seccnt;			/* # sectors processed	    */
+						/****************************/
+	seccnt = 0;				/* Zero count initally	    */
+						/*			    */
+	while (count > 0)			/* Until all sectors xferred*/
+	{					/*			    */
+		__BDOS(SETDMA,buffer);		/* Set new DMA address	    */
+		ccb->fcb.record = sector;	/* Set new record number    */
+		temp=__BDOS(bdosfunc,&(ccb->fcb));/* do the read	    */
+		if(temp != 0)			/* Check for errors	    */
+		{				/****************************/
+			return(seccnt);		/* Return nfg		    */
+		}				/****************************/
+						/*			    */
+		sector++;			/* Increment sector number  */
+		count--;			/* Down count		    */
+		buffer += SECSIZ;		/* Increment address	    */
+		seccnt++;			/* Bump sector count	    */
+	}					/****************************/
+	return(seccnt);				/* All is OK		    */
+}						/****************************/