146 lines
4.9 KiB
C
146 lines
4.9 KiB
C
/* m6810.c: Motorola m6810 RAM emulator
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Copyright (c) 2011, William A. Beech
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Permission is hereby granted, free of charge, to any person obtaining a
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copy of this software and associated documentation files (the "Software"),
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to deal in the Software without restriction, including without limitation
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the rights to use, copy, modify, merge, publish, distribute, sublicense,
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and/or sell copies of the Software, and to permit persons to whom the
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Software is furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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WILLIAM A. BEECH BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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Except as contained in this notice, the name of William A. Beech shall not be
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used in advertising or otherwise to promote the sale, use or other dealings
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in this Software without prior written authorization from William A. Beech.
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These functions support a simulated m6810 RAM device on a CPU board. The
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byte get and put routines use an offset into the RAM image to locate the
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proper byte. This allows another device to set the base address for the
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M6810.
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*/
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#include <stdio.h>
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#include "swtp_defs.h"
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/* function prototypes */
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t_stat m6810_reset (DEVICE *dptr);
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int32 m6810_get_mbyte(int32 offset);
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void m6810_put_mbyte(int32 offset, int32 val);
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/* SIMH RAM Standard I/O Data Structures */
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UNIT m6810_unit = { UDATA (NULL, UNIT_BINK, 128),
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0 };
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MTAB m6810_mod[] = {
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{ 0 }
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};
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DEBTAB m6810_debug[] = {
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{ "ALL", DEBUG_all },
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{ "FLOW", DEBUG_flow },
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{ "READ", DEBUG_read },
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{ "WRITE", DEBUG_write },
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{ "LEV1", DEBUG_level1 },
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{ "LEV2", DEBUG_level2 },
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{ NULL }
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};
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DEVICE m6810_dev = {
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"M6810", //name
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&m6810_unit, //units
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NULL, //registers
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m6810_mod, //modifiers
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1, //numunits
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16, //aradix
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32, //awidth
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1, //aincr
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16, //dradix
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8, //dwidth
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NULL, //examine
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NULL, //deposit
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&m6810_reset, //reset
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NULL, //boot
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NULL, //attach
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NULL, //detach
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NULL, //ctxt
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DEV_DEBUG, //flags
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0, //dctrl
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m6810_debug, //debflags
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NULL, //msize
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NULL //lname
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};
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/* global variables */
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/* m6810_reset */
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t_stat m6810_reset (DEVICE *dptr)
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{
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if (m6810_dev.dctrl & DEBUG_flow)
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printf("m6810_reset: \n");
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if (m6810_unit.filebuf == NULL) {
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m6810_unit.filebuf = malloc(128);
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if (m6810_unit.filebuf == NULL) {
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printf("m6810_reset: Malloc error\n");
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return SCPE_MEM;
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}
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m6810_unit.capac = 128;
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}
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if (m6810_dev.dctrl & DEBUG_flow)
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printf("m6810_reset: Done\n");
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return SCPE_OK;
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}
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/* I/O instruction handlers, called from the CPU module when an
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RAM memory read or write is issued.
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*/
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/* get a byte from memory - from offset from start of RAM*/
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int32 m6810_get_mbyte(int32 offset)
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{
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int32 val;
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if (m6810_dev.dctrl & DEBUG_read)
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printf("m6810_get_mbyte: offset=%04X\n", offset);
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if (((t_addr)offset) < m6810_unit.capac) {
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val = *((uint8 *)(m6810_unit.filebuf) + offset) & 0xFF;
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if (m6810_dev.dctrl & DEBUG_read)
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printf("val=%04X\n", val);
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return val;
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} else {
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if (m6810_dev.dctrl & DEBUG_read)
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printf("m6810_get_mbyte: out of range\n");
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return 0xFF;
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}
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}
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/* put a byte to memory */
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void m6810_put_mbyte(int32 offset, int32 val)
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{
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if (m6810_dev.dctrl & DEBUG_write)
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printf("m6810_put_mbyte: offset=%04X, val=%02X\n", offset, val);
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if ((t_addr)offset < m6810_unit.capac) {
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*((uint8 *)(m6810_unit.filebuf) + offset) = val & 0xFF;
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return;
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} else {
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if (m6810_dev.dctrl & DEBUG_write)
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printf("m6810_put_mbyte: out of range\n");
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return;
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}
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}
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/* end of m6810.c */
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