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70 lines
2.0 KiB
C
70 lines
2.0 KiB
C
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/****************************************************************
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* *
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* CP/M-68K BDOS Disk I/O System Module *
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* *
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* This module translates from the packet oriented I/O *
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* passed from the other BDOS modules into BIOS calls. *
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* *
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* It includes only one external entry point:
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* do_phio() - do physical i/o *
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* *
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* *
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* Configured for Alcyon C on the VAX *
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* *
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****************************************************************/
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#include "stdio.h" /* Standard I/O declarations */
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#include "bdosdef.h" /* Type and structure declarations for BDOS */
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#include "pktio.h" /* Packet I/O definitions */
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#include "biosdef.h" /* Declarations for BIOS entry points */
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EXTERN udiv(); /* Assembly language unsigned divide routine */
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/* in bdosif.s. It's used because Alcyon C */
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/* can't do / or % without an external */
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/************************
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* do_phio entry point *
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************************/
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UWORD do_phio(iop)
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REG struct iopb *iop; /* iop is a pointer to a i/o parameter block */
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{
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REG struct dph *hdrp; /* pointer to disk parameter header */
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REG struct dpb *dparmp; /* pointer to disk parameter block */
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struct
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{ /* structure for results of external divide */
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UWORD iotrk;
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UWORD iosect;
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} iopdiv;
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LOCK /* lock the disk system while doing physical i/o */
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switch (iop->iofcn)
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{
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case sel_info:
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iop->infop = bseldsk(iop->devnum, iop->ioflags);
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break;
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case read:
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hdrp = iop->infop;
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dparmp = hdrp->dpbp;
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udiv( iop->devadr, dparmp->spt, &iopdiv );
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bsettrk( iopdiv.iotrk + dparmp->trk_off );
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bsetsec( bsectrn( iopdiv.iosect, hdrp->xlt ) );
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bsetdma(iop->xferadr);
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return(bread());
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}
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UNLOCK
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return(0);
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}
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return(0);
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}
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