142 lines
4.2 KiB
C
142 lines
4.2 KiB
C
/* cpu.c: Intel MDS-800 CPU Module 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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5 October 2017 - Original file.
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*/
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#include "system_defs.h"
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/* function prototypes */
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t_stat SBC_config(void);
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t_stat SBC_reset (DEVICE *dptr);
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uint8 get_mbyte(uint16 addr);
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uint16 get_mword(uint16 addr);
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void put_mbyte(uint16 addr, uint8 val);
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void put_mword(uint16 addr, uint16 val);
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// globals
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int onetime = 0;
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/* external function prototypes */
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extern t_stat monitor_reset (void);
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extern t_stat monitor_cfg(void);
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extern t_stat fp_reset (void);
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extern t_stat fp_cfg(void);
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extern t_stat i8080_reset (DEVICE *dptr); /* reset the 8080 emulator */
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extern uint8 EPROM_get_mbyte(uint16 addr, uint8 devnum);
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extern t_stat multibus_cfg(void);
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extern uint8 multibus_get_mbyte(uint16 addr);
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extern void multibus_put_mbyte(uint16 addr, uint8 val);
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extern uint8 reg_dev(uint8 (*routine)(t_bool, uint8, uint8), uint8, uint8);
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extern t_stat i3214_cfg(uint8 base, uint8 devnum);
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// external globals
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extern uint8 monitor_boot;
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extern DEVICE i8080_dev;
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extern uint8 i3214_mask;
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extern uint8 EPROM_enable;
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extern uint8 i3214_cnt;
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extern uint8 i3214_ram[16];
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extern uint8 BUS_OVERRIDE;
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t_stat SBC_config(void)
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{
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sim_printf("Configuring MDS-800 CPU Card\n Onboard Devices:\n");
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i3214_cfg(I3214_BASE, 0);
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fp_cfg();
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monitor_cfg();
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return SCPE_OK;
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}
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/* SBC reset routine
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put here to cause a reset of the entire MDS-800 system */
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t_stat SBC_reset (DEVICE *dptr)
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{
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if (onetime == 0) {
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SBC_config();
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multibus_cfg();
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onetime++;
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}
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i8080_reset(&i8080_dev);
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EPROM_enable = 1;
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BUS_OVERRIDE = 0;
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fp_reset();
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monitor_reset();
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return SCPE_OK;
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}
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// memory operations
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/* get a byte from memory - handle RAM, ROM and Multibus memory */
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uint8 get_mbyte(uint16 addr)
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{
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uint8 val;
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if (((monitor_boot & 0x04) == 0) && (addr >= ROM_BASE_0) && (addr <= (ROM_BASE_0 + ROM_SIZE_0)))
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val = EPROM_get_mbyte(addr, 0);
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else if ((addr >= ROM_BASE_1) && (addr <= (ROM_BASE_1 + ROM_SIZE_1)))
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val = EPROM_get_mbyte(addr, 1);
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else
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val = multibus_get_mbyte(addr);
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val &= 0xFF;
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return val;
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}
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/* get a word from memory */
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uint16 get_mword(uint16 addr)
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{
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uint16 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 and Multibus memory */
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void put_mbyte(uint16 addr, uint8 val)
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{
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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(uint16 addr, uint16 val)
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{
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put_mbyte(addr, val & 0xff);
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put_mbyte(addr+1, val >> 8);
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}
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/* end of cpu.c */
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