/*
* Executes a given instruction, or errors out
* ins - instruction to run
*/
void
execute (unsigned short int ins)
{
/* seperate instruction into parts */
short int a0 = (ins >> 12) % 16;
short int a1 = (ins >> 8) % 16;
short int a2 = (ins >> 4) % 16;
short int a3 = (ins >> 0) % 16;
/* Run associated instruction */
switch(a0) {
case 0x0:
_add (a1, a2, a3);
break;
case 0x1:
_sub (a1, a2, a3);
break;
case 0x2:
_mul (a1, a2, a3);
break;
case 0x3:
_div (a1, a2, a3);
break;
case 0x6:
_beq (a1, a2, a3);
break;
case 0x7:
_bgt (a1, a2, a3);
break;
case 0x8:
_ld (a1, a2, a3);
break;
case 0x9:
_st (a1, a2, a3);
break;
case 0xa:
_lc (a1, a3);
break;
case 0xb:
_jmp (a1, a3);
break;
case 0xc:
_inc (a1, a3);
break;
case 0xf:
_sys (a1, a3);
break;
default:
printf ("Error: invalid opcode %#x.\n", a0);
sys_dump (0x0);
sys_halt (0x0);
}
}
int main(int argc, char **argv)
{
char *filename, *x;
char buf[20];
FILE *file;
unsigned char *buffer;
size_t filen, buflen = 32768l + 1;
struct regs regs;
struct __iocb *iocb = findfreeiocb();
int iocb_num;
/* if DOS will automatically clear the screen after the program exits, wait for a keypress... */
if (doesclrscrafterexit())
atexit((void (*)(void))cgetc);
if (! iocb) {
fprintf(stderr, "couldn't find a free iocb\n");
return 1;
}
iocb_num = (iocb - &IOCB) * 16;
if (verbose)
printf("using iocb index $%02X ($%04X)\n", iocb_num, iocb);
if (argc < 2) {
printf("\nfilename: ");
x = fgets(buf, 19, stdin);
printf("\n");
if (! x) {
printf("empty filename, exiting...\n");
return 1;
}
if (*x && *(x + strlen(x) - 1) == '\n')
*(x + strlen(x) - 1) = 0;
if (! strlen(x)) { /* empty filename */
printf("empty filename, exiting...\n");
return 1;
}
filename = x;
}
else {
filename = *(argv+1);
}
/* allocate buffer */
buffer = malloc(buflen);
if (! buffer) {
buflen = _heapmaxavail(); /* get as much as we can */
buffer = malloc(buflen);
if (! buffer) {
fprintf(stderr, "cannot alloc %ld bytes -- aborting...\n", (long)buflen);
return 1;
}
}
if (verbose)
printf("buffer size: %ld bytes\n", (long)buflen);
/* open file */
file = fopen(filename, "rb");
if (! file) {
free(buffer);
fprintf(stderr, "cannot open '%s': %s\n", filename, strerror(errno));
return 1;
}
/* read file -- file length must be < 32K */
if (verbose)
printf("reading input file...\n");
filen = fread(buffer, 1, buflen, file);
if (! filen) {
fprintf(stderr, "read error\n");
file_err:
fclose(file);
free(buffer);
return 1;
}
if (filen > 32767l) {
fprintf(stderr, "file is too large (must be < 32768)\n");
goto file_err;
}
if (filen == buflen) { /* we have a buffer < 32768 and the file fits into it (and is most probably larger) */
fprintf(stderr, "not enough memory\n");
goto file_err;
}
if (verbose)
printf("file size: %ld bytes\n", (long)filen);
/* close input file */
fclose(file);
/* open cassette */
if (verbose)
printf("opening cassette...\n");
iocb->buffer = C_dev;
iocb->aux1 = 8; /* open for output */
iocb->aux2 = 128; /* short breaks and no stop between data blocks */
iocb->command = IOCB_OPEN;
regs.x = iocb_num;
regs.pc = 0xe456; /* CIOV */
_sys(®s);
if (regs.y != 1) {
fprintf(stderr, "CIO call to open cassette returned %d\n", regs.y);
free(buffer);
return 1;
}
/* write file */
if (verbose)
printf("writing to cassette...\n");
iocb->buffer = buffer;
iocb->buflen = filen;
iocb->command = IOCB_PUTCHR;
regs.x = iocb_num;
regs.pc = 0xe456; /* CIOV */
_sys(®s);
if (regs.y != 1) {
fprintf(stderr, "CIO call to write file returned %d\n", regs.y);
free(buffer);
iocb->command = IOCB_CLOSE;
regs.x = iocb_num;
regs.pc = 0xe456; /* CIOV */
_sys(®s);
return 1;
}
/* free buffer */
free(buffer);
/* close cassette */
iocb->command = IOCB_CLOSE;
regs.x = iocb_num;
regs.pc = 0xe456; /* CIOV */
_sys(®s);
if (regs.y != 1) {
fprintf(stderr, "CIO call to close cassette returned %d\n", regs.y);
return 1;
}
/* all is fine */
printf("success\n");
return 0;
}
