/*	SCSIEMDV.c 	Copyright (C) 2004 Philip Cummins, Paul C. Pratt 	You can redistribute this file and/or modify it under the terms	of version 2 of the GNU General Public License as published by	the Free Software Foundation.  You should have received a copy	of the license along with this file; see the file COPYING. 	This file is distributed in the hope that it will be useful,	but WITHOUT ANY WARRANTY; without even the implied warranty of	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the	license for more details.*/ /*	Small Computer System Interface EMulated DeVice 	Emulates the SCSI found in the Mac Plus. 	This code adapted from "SCSI.c" in vMac by Philip Cummins.*/ /* NCR5380 chip emulation by Yoav Shadmi, 1998 */ #ifndef AllFiles#include "SYSDEPNS.h" #include "ENDIANAC.h"#include "MYOSGLUE.h"#include "EMCONFIG.h"#include "GLOBGLUE.h"#include "MINEM68K.h"#endif #include "SCSIEMDV.h" #define scsiRd   0x00#define scsiWr   0x01 #define sCDR     0x00 /* current scsi data register  (r/o) */#define sODR     0x00 /* output data register        (w/o) */#define sICR     0x02 /* initiator command register  (r/w) */#define sMR      0x04 /* mode register               (r/w) */#define sTCR     0x06 /* target command register     (r/w) */#define sCSR     0x08 /* current SCSI bus status     (r/o) */#define sSER     0x08 /* select enable register      (w/o) */#define sBSR     0x0A /* bus and status register     (r/o) */#define sDMAtx   0x0A /* start DMA send              (w/o) */#define sIDR     0x0C /* input data register         (r/o) */#define sTDMArx  0x0C /* start DMA target receive    (w/o) */#define sRESET   0x0E /* reset parity/interrupt      (r/o) */#define sIDMArx  0x0E /* start DMA initiator receive (w/o) */ #define kSCSI_Size 0x00010 LOCALVAR ui3b SCSI[kSCSI_Size]; GLOBALPROC SCSI_Reset(void){	int i; 	for (i = 0; i < kSCSI_Size; i++) {		SCSI[i] = 0;	}} LOCALPROC SCSI_BusReset(void){	SCSI[scsiRd + sCDR] = 0;	SCSI[scsiWr + sODR] = 0;	SCSI[scsiRd + sICR] = 0x80;	SCSI[scsiWr + sICR] &= 0x80;	SCSI[scsiRd + sMR] &= 0x40;	SCSI[scsiWr + sMR] &= 0x40;	SCSI[scsiRd + sTCR] = 0;	SCSI[scsiWr + sTCR] = 0;	SCSI[scsiRd + sCSR] = 0x80;	SCSI[scsiWr + sSER] = 0;	SCSI[scsiRd + sBSR] = 0x10;	SCSI[scsiWr + sDMAtx] = 0;	SCSI[scsiRd + sIDR] = 0;	SCSI[scsiWr + sTDMArx] = 0;	SCSI[scsiRd + sRESET] = 0;	SCSI[scsiWr + sIDMArx] = 0;#if 0	SCSI[scsiRd + sODR + dackWr] = 0;	SCSI[scsiWr + sIDR + dackRd] = 0;#endif 	/* The missing piece of the puzzle.. :) */	put_ram_word(0xb22, get_ram_word(0xb22) | 0x8000);} LOCALPROC SCSI_Check(void){	/*		The arbitration select/reselect scenario		[stub.. doesn't really work...]	*/	if ((SCSI[scsiWr + sODR] >> 7) == 1) {		/* Check if the Mac tries to be an initiator */		if ((SCSI[scsiWr + sMR] & 1) == 1) {			/* the Mac set arbitration in progress */			/*				stub! tell the mac that there				is arbitration in progress...			*/			SCSI[scsiRd + sICR] |= 0x40;			/* ... that we didn't lose arbitration ... */			SCSI[scsiRd + sICR] &= ~ 0x20;			/*				... and that there isn't a higher priority ID present...			*/			SCSI[scsiRd + sCDR] = 0x00; 			/*				... the arbitration and selection/reselection is				complete. the initiator tries to connect to the SCSI				device, fails and returns after timeout.			*/		}	} 	/* check the chip registers, AS SET BY THE CPU */	if ((SCSI[scsiWr + sICR] >> 7) == 1) {		/* Check Assert RST */		SCSI_BusReset();	} else {		SCSI[scsiRd + sICR] &= ~ 0x80;		SCSI[scsiRd + sCSR] &= ~ 0x80;	} 	if ((SCSI[scsiWr + sICR] >> 2) == 1) {		/* Check Assert SEL */		SCSI[scsiRd + sCSR] |= 0x02;		SCSI[scsiRd + sBSR] = 0x10;	} else {		SCSI[scsiRd + sCSR] &= ~ 0x02;	}} GLOBALFUNC ui5b SCSI_Access(ui5b Data, blnr WriteMem, CPTR addr){	if (addr < (kSCSI_Size / 2)) {		addr *= 2;		if (WriteMem) {			SCSI[addr + 1] = Data;			SCSI_Check();		} else {			Data = SCSI[addr];		}	}	return Data;}