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Code Issues Releases Wiki Activity

Reverted to better old copy

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This commit is contained in:
Ross Wilson
2015-10-16 10:25:47 +07:00
parent b211efcb06
commit c39b4644ca
25 changed files with 266 additions and 732 deletions
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182
vimlac/dcpu.c
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@@ -1,105 +1,56 @@
/******************************************************************************\
* dcpu.c *
* -------- *
* dcpu.c *
* ------- *
* *
* This file is used to decode and execute a display processor instruction. *
* *
\******************************************************************************/
#include "imlac.h"
#include "vimlac.h"
#include "dcpu.h"
#include "memory.h"
#include "trace.h"
/******
* Emulated registers, state, memory, etc.
******/
static WORD r_DPC;
static WORD Prev_r_DPC;
static WORD DRSindex = 0;
static WORD r_PC;
static WORD Prev_r_PC;
static int r_DRSindex;
/* 40Hz sync stuff */
static bool Sync40HzOn = false;
/******
* Environment stuff. PTR and TTY in and out files, etc
******/
static bool dcpu_on; /* true if display processor is running */
static bool dcpu_sync_on; /* true if 40HZ flag set */
static bool cpu_is_on; /* true if display processor is running */
/******************************************************************************
Description : Function to get the display CPU status.
Parameters :
Returns :
Comments :
******************************************************************************/
bool
dcpu_running(void)
{
return dcpu_on == true;
}
/******************************************************************************
Description : Function to start the display CPU.
Parameters :
Returns :
Comments :
******************************************************************************/
void
dcpu_start(void)
{
dcpu_on = true;
}
/******************************************************************************
Description : Function to stop the display CPU.
Parameters :
Returns :
Comments :
******************************************************************************/
void
dcpu_stop(void)
{
dcpu_on = false;
}
/******************************************************************************
Description : Functions to get various registers.
Description : Functions to get/set various registers.
Parameters :
Returns :
Comments :
******************************************************************************/
WORD
dcpu_get_DPC(void)
dcpu_get_PC(void)
{
return r_DPC;
}
WORD
dcpu_get_prev_DPC(void)
{
return Prev_r_DPC;
return r_PC;
}
void
dcpu_set_DPC(WORD new_dpc)
dcpu_set_PC(WORD value)
{
r_DPC = new_dpc;
r_PC = value;
}
void
dcpu_set_DRSindex(WORD drsindex)
dcpu_set_DRSindex(int value)
{
DRSindex = drsindex;
r_DRSindex = value;
}
@@ -112,55 +63,44 @@ Description : Function to handle unrecognized instruction.
static void
illegal(void)
{
WORD oldDPC = Prev_r_DPC & MEMMASK;
WORD oldPC = Prev_r_PC & MEMMASK;
/* memdump(LogOut, oldPC - 8, 16); */
error("INTERNAL ERROR: "
"unexpected display processor opcode %06.6o at address %06.6o",
mem_get(oldDPC, false), oldDPC);
}
/******************************************************************************
Description :
Parameters :
Returns :
Comments :
******************************************************************************/
static int
i_LAW_LWC(bool indirect, WORD address)
{
return 1;
"unexpected main processor opcode %06.6o at address %06.6o",
mem_get(oldPC, false), oldPC);
}
/******************************************************************************
Description : Function to execute one display processor instruction.
Parameters :
Returns : The number of cycles the instruction took.
Returns :
Comments :
******************************************************************************/
int
dcpu_execute_one(void)
{
WORD instruction;
WORD opcode;
WORD address;
bool indirect;
WORD instruction = 0;
bool indirect = false;
WORD opcode = 0;
WORD address = 0;
/******
* If main processor not running, return immediately.
* If processor not running, return immediately.
******/
if (!dcpu_on)
if (!cpu_is_on)
return 0;
/******
* Fetch the instruction. Split into initial opcode and address.
******/
Prev_r_DPC = r_DPC;
instruction = mem_get(r_DPC++, false);
r_DPC = r_DPC & MEMMASK;
Prev_r_PC = r_PC;
instruction = mem_get(r_PC++, false);
r_PC = r_PC & MEMMASK;
indirect = (bool) (instruction & 0100000); /* high bit set? */
opcode = (instruction >> 11) & 017; /* high 5 bits */
@@ -170,12 +110,70 @@ dcpu_execute_one(void)
* Now decode it.
******/
#ifdef JUNK
switch (opcode)
{
default: illegal();
}
#endif
++instruction;
indirect = !indirect;
++opcode;
++address;
illegal();
return 0; /* CAN'T REACH */
return 0;
}
/******************************************************************************
Description : Function to get CPU state.
Parameters :
Returns :
Comments :
******************************************************************************/
bool
dcpu_on(void)
{
return cpu_is_on;
}
/******************************************************************************
Description : Function to start the CPU.
Parameters :
Returns :
Comments :
******************************************************************************/
void
dcpu_start(void)
{
cpu_is_on = true;
}
/******************************************************************************
Description : Function to stop the CPU.
Parameters :
Returns :
Comments :
******************************************************************************/
void
dcpu_stop(void)
{
cpu_is_on = false;
}
/******************************************************************************
Description : Function to stop the CPU.
Parameters :
Returns :
Comments :
******************************************************************************/
void
dcpu_set_drsindex(int index)
{
r_DRSindex = index;
}