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Add single stepping to lib6502 adn complete Apple 1+CFFA emulation
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@highlander-robotics
highlander-robotics committed Mar 9, 2024
1 parent 8344f18 commit db424e9
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256 changes: 244 additions & 12 deletions src/lib6502/a1cffa.c
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Expand Up @@ -28,6 +28,10 @@
#include <stdarg.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <termios.h>

#include "config.h"
#include "lib6502.h"
Expand All @@ -37,6 +41,139 @@
typedef uint8_t byte;
typedef uint16_t word;

int keycode_to_a2code[128] =
{
-1, // KEY_RESERVED
0x35, // KEY_ESC
0x12, // KEY_1
0x13, // KEY_2
0x14, // KEY_3
0x15, // KEY_4
0x17, // KEY_5
0x16, // KEY_6
0x1A, // KEY_7
0x1C, // KEY_8
0x19, // KEY_9
0x1D, // KEY_0
0x1B, // KEY_MINUS
0x18, // KEY_EQUAL
0x3B, // KEY_BACKSPACE0
0x30, // KEY_TAB
0x0C, // KEY_Q
0x0D, // KEY_W
0x0E, // KEY_E
0x0F, // KEY_R
0x11, // KEY_T
0x10, // KEY_Y
0x20, // KEY_U
0x22, // KEY_I
0x1F, // KEY_O
0x23, // KEY_P
0x21, // KEY_LEFTBRACE
0x1E, // KEY_RIGHTBRACE
0x24, // KEY_ENTER
0x36, // KEY_LEFTCTRL
0x00, // KEY_A
0x01, // KEY_S
0x02, // KEY_D
0x03, // KEY_F
0x05, // KEY_G
0x04, // KEY_H
0x26, // KEY_J
0x28, // KEY_K
0x25, // KEY_L
0x29, // KEY_SEMICOLON
0x27, // KEY_APOSTROPHE
0x32, // KEY_GRAVE
0x38, // KEY_LEFTSHIFT
0x2A, // KEY_BACKSLASH
0x06, // KEY_Z
0x07, // KEY_X
0x08, // KEY_C
0x09, // KEY_V
0x0B, // KEY_B
0x2D, // KEY_N
0x2E, // KEY_M
0x2B, // KEY_COMMA
0x2F, // KEY_DOT
0x2C, // KEY_SLASH
0x38, // KEY_RIGHTSHIFT
0x43, // KEY_KPASTERISK
0x37, // KEY_LEFTALT
0x31, // KEY_SPACE
0x39, // KEY_CAPSLOCK
0x7A, // KEY_F1
0x78, // KEY_F2
0x63, // KEY_F3
0x76, // KEY_F4
0x60, // KEY_F5
0x61, // KEY_F6
0x62, // KEY_F7
0x64, // KEY_F8
0x65, // KEY_F9
0x6D, // KEY_F10
0x47, // KEY_NUMLOCK
0x37, // KEY_SCROLLLOCK
0x59, // KEY_KP7
0x5B, // KEY_KP8
0x5C, // KEY_KP9
0x4E, // KEY_KPMINUS
0x56, // KEY_KP4
0x57, // KEY_KP5
0x58, // KEY_KP6
0x45, // KEY_KPPLUS
0x53, // KEY_KP1
0x54, // KEY_KP2
0x55, // KEY_KP3
0x52, // KEY_KP0
0x41, // KEY_KPDOT
-1,
-1, // KEY_ZENKAKUHANKAKU
-1, // KEY_102ND
0x67, // KEY_F11
0x6F, // KEY_F12
-1, // KEY_RO
-1, // KEY_KATAKANA
-1, // KEY_HIRAGANA
-1, // KEY_HENKAN
-1, // KEY_KATAKANAHIRAGANA
-1, // KEY_MUHENKAN
-1, // KEY_KPJPCOMMA
0x4C, // KEY_KPENTER
0x36, // KEY_RIGHTCTRL
0x4B, // KEY_KPSLASH
0x7F, // KEY_SYSRQ
0x37, // KEY_RIGHTALT
0x6E, // KEY_LINEFEED
0x73, // KEY_HOME
0x3E, // KEY_UP
0x74, // KEY_PAGEUP
0x3B, // KEY_LEFT
0x3C, // KEY_RIGHT
0x77, // KEY_END
0x3D, // KEY_DOWN
0x79, // KEY_PAGEDOWN
0x72, // KEY_INSERT
0x33, // KEY_DELETE
-1, // KEY_MACRO
-1, // KEY_MUTE
-1, // KEY_VOLUMEDOWN
-1, // KEY_VOLUMEUP
0x7F, // KEY_POWER /* SC System Power Down */
0x51, // KEY_KPEQUAL
0x4E, // KEY_KPPLUSMINUS
-1, // KEY_PAUSE
-1, // KEY_SCALE /* AL Compiz Scale (Expose) */
0x2B, // KEY_KPCOMMA
-1, // KEY_HANGEUL
-1, // KEY_HANJA
-1, // KEY_YEN
0x3A, // KEY_LEFTMETA
0x3A, // KEY_RIGHTMETA
-1 // KEY_COMPOSE
};
struct termios org_tio;

void pfail(const char *msg)
{
fflush(stdout);
Expand Down Expand Up @@ -83,40 +220,100 @@ int load(M6502 *mpu, word address, const char *path)
return 1;
}

//
// CFFA1 zero page addresses.
//
#define CFFADest 0x00
#define CFFAFileName 0x02
#define CFFAOldName 0x04
#define CFFAFileType 0x06
#define CFFAAuxType 0x07
#define CFFAFileSize 0x09
#define CFFAEntryPtr 0x0B

int cffa1(M6502 *mpu, word address, byte data)
{
char *fileptr, filename[64];
int addr;
struct stat sbuf;

switch (mpu->registers->x)
{
case 0x7A: /* perform keyboard scan */
mpu->registers->x= 0x00;
case 0x02: /* quit */
exit(0);
break;
case 0x14: /* find dir entry */
addr = mpu->memory[CFFAFileName] | (mpu->memory[CFFAFileName + 1] << 8);
memset(filename, 0, 64);
strncpy(filename, (char *)(mpu->memory + addr + 1), mpu->memory[addr]);
strcat(filename, "#FE1000");
if (!(stat(filename, &sbuf)))
{
/* DirEntry @ $9100 */
mpu->memory[CFFAEntryPtr] = 0x00;
mpu->memory[CFFAEntryPtr + 1] = 0x91;
mpu->memory[0x9115] = sbuf.st_size;
mpu->memory[0x9116] = sbuf.st_size >> 8;
mpu->registers->a = 0;
}
else
mpu->registers->a = -1;
break;
case 0x22: /* load file */
addr = mpu->memory[CFFAFileName] | (mpu->memory[CFFAFileName + 1] << 8);
memset(filename, 0, 64);
strncpy(filename, (char *)(mpu->memory + addr + 1), mpu->memory[addr]);
strcat(filename, "#FE1000");
addr = mpu->memory[CFFADest] | (mpu->memory[CFFADest + 1] << 8);
mpu->registers->a = load(mpu, addr, filename) - 1;
break;

default:
{
char state[64];
fprintf(stderr, "Unimplemented CFFA function: %02X\n", mpu->registers->x);
M6502_dump(mpu, state);
fflush(stdout);
fprintf(stderr, "\nCFFA1 %s\n", state);
fail("ABORT");
pfail("ABORT");
}
break;
}
rts;
}

int bye(M6502 *mpu, word addr, byte data) { exit(0); return 0; }
int cout(M6502 *mpu, word addr, byte data) { putchar(mpu->registers->a); fflush(stdout); rts; }
int cout(M6502 *mpu, word addr, byte data) { if (mpu->registers->a == 0x8D) putchar('\n'); putchar(mpu->registers->a & 0x7F); fflush(stdout); rts; }

int rd6820kbdctl(M6502 *mpu, word addr, byte data) { return 0x80; }
unsigned keypending = 0;
unsigned char keypressed(void)
{
unsigned char cin;
if (read(STDIN_FILENO, &cin, 1) > 0)
keypending = cin | 0x80;
return keypending & 0x80;
}
unsigned char keyin(void)
{
unsigned char cin;

if (!keypending)
keypressed();
cin = keypending;
keypending = 0;
return cin;
}
int rd6820kbdctl(M6502 *mpu, word addr, byte data) { return keypressed(); }
int rd6820vidctl(M6502 *mpu, word addr, byte data) { return 0x00; }
int rd6820kbd(M6502 *mpu, word addr, byte data) { return getchar(); }
int wr6820vid(M6502 *mpu, word addr, byte data) { putchar(data); fflush(stdout); return 0; }
int rd6820kbd(M6502 *mpu, word addr, byte data) { return keyin(); }
int rd6820vid(M6502 *mpu, word addr, byte data) { return 0x80; }
int wr6820vid(M6502 *mpu, word addr, byte data) { if (data == 0x8D) putchar('\n'); putchar(data & 0x7F); fflush(stdout); return 0; }

int setTraps(M6502 *mpu)
{
/* Apple 1 memory-mapped IO */
M6502_setCallback(mpu, read, 0xD010, rd6820kbd);
M6502_setCallback(mpu, read, 0xD011, rd6820kbdctl);
M6502_setCallback(mpu, read, 0xD012, rd6820vid);
M6502_setCallback(mpu, write, 0xD012, wr6820vid);
M6502_setCallback(mpu, read, 0xD013, rd6820vidctl);
/* CFFA1 and ROM calls */
Expand All @@ -126,18 +323,53 @@ int setTraps(M6502 *mpu)
return 0;
}

void resetInput(void)
{
tcsetattr(STDIN_FILENO, TCSANOW, &org_tio);
}
void setRawInput(void)
{
struct termios termio;

// Save input settings.
tcgetattr(STDIN_FILENO, &termio); /* save current port settings */
memcpy(&org_tio, &termio, sizeof(struct termios));
termio.c_cflag = /*BAUDRATE | CRTSCTS |*/ CS8 | CLOCAL | CREAD;
termio.c_iflag = IGNPAR;
termio.c_oflag = 0;
termio.c_lflag = 0; /* set input mode (non-canonical, no echo,...) */
termio.c_cc[VTIME] = 0; /* inter-character timer unused */
termio.c_cc[VMIN] = 0; /* non-blocking read */
tcsetattr(STDIN_FILENO, TCSANOW, &termio);
atexit(resetInput);
}
int main(int argc, char **argv)
{
char *interpfile = "A1PLASMA";
char *interpfile = "A1PLASMA#060280";
char *program= argv[0];
M6502 *mpu = M6502_new(0, 0, 0);

if (argc == 2)
interpfile = argv[1];
while (++argv, --argc > 0)
{
if (!strcmp(*argv, "-t")) mpu->flags |= M6502_SingleStep;
else
if (argv[0][0] != '-') interpfile = *argv;
else fprintf(stderr, "Usage: %s [-t] [interpreter file]", program);
}
if (!load(mpu, 0x280, interpfile))
pfail(interpfile);
setRawInput();
setTraps(mpu);
M6502_reset(mpu);
M6502_run(mpu);
mpu->registers->pc = 0x0280;
while (M6502_run(mpu))
{
char state[64];
char insn[64];
M6502_dump(mpu, state);
M6502_disassemble(mpu, mpu->registers->pc, insn);
printf("%s : %s\n", state, insn);
}
M6502_delete(mpu);
return 0;
}
15 changes: 9 additions & 6 deletions src/lib6502/lib6502.c
View file
Expand Up @@ -584,7 +584,7 @@ enum {
tick(ticks); \
fflush(stdout); \
fprintf(stderr, "\nundefined instruction %02X\n", memory[PC-1]); \
return;
return 0;

#define phR(ticks, adrmode, R) \
fetch(); \
Expand Down Expand Up @@ -744,7 +744,7 @@ static void oops(void)
}


void M6502_run(M6502 *mpu)
int M6502_run(M6502 *mpu)
{
#if defined(__GNUC__) && !defined(__STRICT_ANSI__)

Expand All @@ -768,17 +768,18 @@ void M6502_run(M6502 *mpu)
register void **itabp= &itab[0];
register void *tpc;

# define begin() fetch(); next()
//# define begin() fetch(); next()
# define begin() goto *(itabp[memory[PC++]])
# define fetch() tpc= itabp[memory[PC++]]
# define next() goto *tpc
# define next() if (STEP) { PC--; externalise(); return 1; } goto *tpc
# define dispatch(num, name, mode, cycles) _##num: name(cycles, mode) oops(); next()
# define end()

#else /* (!__GNUC__) || (__STRICT_ANSI__) */

# define begin() for (;;) switch (memory[PC++]) {
# define fetch()
# define next() break
# define next() if (STEP) { externalise(); return 1; } break
# define dispatch(num, name, mode, cycles) case 0x##num: name(cycles, mode); next()
# define end() }

Expand All @@ -790,8 +791,9 @@ void M6502_run(M6502 *mpu)
byte A, X, Y, P, S;
M6502_Callback *readCallback= mpu->callbacks->read;
M6502_Callback *writeCallback= mpu->callbacks->write;
unsigned int STEP;

# define internalise() A= mpu->registers->a; X= mpu->registers->x; Y= mpu->registers->y; P= mpu->registers->p; S= mpu->registers->s; PC= mpu->registers->pc
# define internalise() STEP=mpu->flags&M6502_SingleStep; A= mpu->registers->a; X= mpu->registers->x; Y= mpu->registers->y; P= mpu->registers->p; S= mpu->registers->s; PC= mpu->registers->pc
# define externalise() mpu->registers->a= A; mpu->registers->x= X; mpu->registers->y= Y; mpu->registers->p= P; mpu->registers->s= S; mpu->registers->pc= PC

internalise();
Expand All @@ -809,6 +811,7 @@ void M6502_run(M6502 *mpu)
# undef end

(void)oops;
return 0;
}


Expand Down
5 changes: 3 additions & 2 deletions src/lib6502/lib6502.h
View file
Expand Up @@ -48,14 +48,15 @@ struct _M6502
enum {
M6502_RegistersAllocated = 1 << 0,
M6502_MemoryAllocated = 1 << 1,
M6502_CallbacksAllocated = 1 << 2
M6502_CallbacksAllocated = 1 << 2,
M6502_SingleStep = 1 << 3
};

extern M6502 *M6502_new(M6502_Registers *registers, M6502_Memory memory, M6502_Callbacks *callbacks);
extern void M6502_reset(M6502 *mpu);
extern void M6502_nmi(M6502 *mpu);
extern void M6502_irq(M6502 *mpu);
extern void M6502_run(M6502 *mpu);
extern int M6502_run(M6502 *mpu);
extern int M6502_disassemble(M6502 *mpu, uint16_t addr, char buffer[64]);
extern void M6502_dump(M6502 *mpu, char buffer[64]);
extern void M6502_delete(M6502 *mpu);
Expand Down

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