143 lines
4.7 KiB
C
143 lines
4.7 KiB
C
/* iSBC80-10.c: Intel iSBC 80/10 Processor simulator
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Copyright (c) 2010, 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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This software was written by Bill Beech, Dec 2010, to allow emulation of Multibus
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Computer Systems.
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?? ??? 10 - Original file.
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*/
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#include "system_defs.h"
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/* set the base I/O address for the first 8255 */
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#define I8255_BASE_0 0xE4
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/* set the base I/O address for the second 8255 */
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#define I8255_BASE_1 0xE8
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/* set the base I/O address for the 8251 */
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#define I8251_BASE 0xEC
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/* set the base and size for the EPROM on the iSBC 80/10 */
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#define ROM_SIZE 0x1000
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/* set the base and size for the RAM on the iSBC 80/10 */
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#define RAM_BASE 0x3C00
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#define RAM_SIZE 0x0400
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/* set INTR for CPU */
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#define INTR INT_1
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/* function prototypes */
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int32 get_mbyte(int32 addr);
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int32 get_mword(int32 addr);
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void put_mbyte(int32 addr, int32 val);
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void put_mword(int32 addr, int32 val);
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t_stat SBC_reset (DEVICE *dptr);
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/* external function prototypes */
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extern t_stat i8080_reset (DEVICE *dptr); /* reset the 8080 emulator */
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extern int32 multibus_get_mbyte(int32 addr);
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extern void multibus_put_mbyte(int32 addr, int32 val);
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extern int32 EPROM_get_mbyte(int32 addr);
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extern int32 RAM_get_mbyte(int32 addr);
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extern void RAM_put_mbyte(int32 addr, int32 val);
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extern UNIT i8255_unit;
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extern UNIT EPROM_unit;
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extern UNIT RAM_unit;
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extern t_stat i8255_reset (DEVICE *dptr, int32 base);
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extern t_stat i8251_reset (DEVICE *dptr, int32 base);
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extern t_stat pata_reset (DEVICE *dptr, int32 base);
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extern t_stat EPROM_reset (DEVICE *dptr, int32 size);
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extern t_stat RAM_reset (DEVICE *dptr, int32 base, int32 size);
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/* SBC reset routine */
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t_stat SBC_reset (DEVICE *dptr)
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{
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sim_printf("Initializing iSBC-80/10:\n");
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i8080_reset (NULL);
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i8255_reset (NULL, I8255_BASE_0);
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i8255_reset (NULL, I8255_BASE_1);
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i8251_reset (NULL, I8251_BASE);
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EPROM_reset (NULL, ROM_SIZE);
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RAM_reset (NULL, RAM_BASE, RAM_SIZE);
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return SCPE_OK;
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}
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/* get a byte from memory - handle RAM, ROM, I/O, and Multibus memory */
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int32 get_mbyte(int32 addr)
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{
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int32 val, org, len;
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/* if local EPROM handle it */
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if ((i8255_unit.u5 & 0x01) && (addr >= EPROM_unit.u3) && (addr < (EPROM_unit.u3 + EPROM_unit.capac))) {
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return EPROM_get_mbyte(addr);
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} /* if local RAM handle it */
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if ((i8255_unit.u5 & 0x02) && (addr >= RAM_unit.u3) && (addr < (RAM_unit.u3 + RAM_unit.capac))) {
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return RAM_get_mbyte(addr);
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} /* otherwise, try the multibus */
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return multibus_get_mbyte(addr);
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}
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/* get a word from memory */
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int32 get_mword(int32 addr)
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{
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int32 val;
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val = get_mbyte(addr);
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val |= (get_mbyte(addr+1) << 8);
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return val;
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}
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/* put a byte to memory - handle RAM, ROM, I/O, and Multibus memory */
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void put_mbyte(int32 addr, int32 val)
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{
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/* if local EPROM handle it */
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if ((i8255_unit.u5 & 0x01) && (addr >= EPROM_unit.u3) && (addr <= (EPROM_unit.u3 + EPROM_unit.capac))) {
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sim_printf("Write to R/O memory address %04X - ignored\n", addr);
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return;
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} /* if local RAM handle it */
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if ((i8255_unit.u5 & 0x02) && (addr >= RAM_unit.u3) && (addr <= (RAM_unit.u3 + RAM_unit.capac))) {
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RAM_put_mbyte(addr, val);
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return;
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} /* otherwise, try the multibus */
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multibus_put_mbyte(addr, val);
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}
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/* put a word to memory */
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void put_mword(int32 addr, int32 val)
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{
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put_mbyte(addr, val);
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put_mbyte(addr+1, val >> 8);
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}
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/* end of iSBC80-10.c */
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