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terakdisk.c
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terakdisk.c
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#include "defines.h"
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include "mmap_emu.h"
#include <libintl.h>
#define _(String) gettext (String)
/* Terak floppy images are 128*26*76 = 252928 bytes, single-sided */
#define SECSIZE 64 /* words */
#define SECPERTRACK 26
#define MAXTRACK 76
typedef enum {
nopD, rtcD, stepinD, stepoutD, readtsD, readD, writeD, delD
} disk_cmd;
typedef enum {
enF = 1, headF = 020, intrF = 0100, doneF = 0200,
track0F = 01000, delF = 02000, wrprF = 04000, crcF = 010000,
lateF = 020000, syncF = 040000, errF = 0100000
} disk_flg;
/* Why bother, let's memory-map the files! */
typedef struct {
unsigned length;
unsigned short * image;
unsigned short * ptr;
unsigned char track;
disk_cmd cmd;
unsigned char ro;
unsigned char motor;
unsigned char inprogress;
unsigned char crc;
unsigned char cursec;
} tdisk_t;
tdisk_t tdisks[4];
static int selected = -1;
void tdisk_open(tdisk_t * pdt, char * name) {
int fd = open(name, O_RDWR);
if (fd == -1) {
pdt->ro = 1;
fd = open(name, O_RDONLY);
}
if (fd == -1) {
perror(name);
return;
}
pdt->length = lseek(fd, 0, SEEK_END);
if (pdt->length % SECSIZE) {
fprintf(stderr, _("%s is not an integer number of blocks\n"), name);
close(fd);
return;
}
if (! (pdt->image = file_map (fd, !pdt->ro, pdt->length)))
perror(name);
if (pdt->ro) {
fprintf(stderr, _("%s will be read only\n"), name);
}
}
/* Are there any interrupts to open or close ? */
void tdisk_init() {
static char init_done = 0;
int i;
if (!init_done) {
disk_open(&tdisks[0], floppyA);
disk_open(&tdisks[1], floppyB);
disk_open(&tdisks[2], floppyC);
disk_open(&tdisks[3], floppyD);
init_done = 1;
}
for (i = 0; i < 4; i++) {
tdisks[i].ptr = NULL;
tdisks[i].track =
tdisks[i].motor =
tdisks[i].inprogress = 0;
}
selected = -1;
} // tdisk_init
void tdisk_finish() {
int i;
for (i = 0; i < 4; i++) {
if (!tdisks[i].image)
continue;
file_unmap (tdisks[i].image, tdisks[i].length, !tdisks[i].ro);
}
}
static inline unsigned unit(d_word word) {
return (word >> 8) & 3;
}
static inline disk_cmd cmd(d_word word) {
return (word >> 1) & 7;
}
static CPU_RES tdisk_read(c_addr addr, d_word *word) {
d_word offset = addr - TERAK_DISK_REG;
tdisk_t * pdt = &tdisks[selected];
switch(offset) {
case 0: /* status */
if (selected == -1) {
*word = errF | doneF;
break;
}
*word = (pdt->track ? 0 : track0F) | (pdt->ro ? wrprF : 0) | headF | doneF;
if (!pdt->inprogress) {
/* no operation started yet */
return CPU_OK;
} else switch (pdt->cmd) {
case nopD:
case rtcD:
case writeD:
case delD:
break;
case stepinD:
if (pdt->track == MAXTRACK)
*word |= errF;
else if (pdt->inprogress) {
pdt->track++;
fprintf(stderr, "trk = %d\n", pdt->track);
}
break;
case stepoutD:
if (pdt->track == 0)
*word |= errF;
else if (pdt->inprogress) {
pdt->track--;
fprintf(stderr, "trk = %d\n", pdt->track);
}
break;
case readtsD:
/* present all sectors round-robin */
if (pdt->inprogress) {
pdt->cursec %= SECPERTRACK;
pdt->cursec++;
}
break;
case readD:
fprintf(stderr, "Reading track %d, sector %d\n",
pdt->track, pdt->cursec);
pdt->ptr = pdt->image +
pdt->track*SECPERTRACK*SECSIZE +
(pdt->cursec-1)*SECSIZE;
break;
}
pdt->inprogress = 0;
break;
case 2: /* data */
switch (pdt->cmd) {
case readtsD:
*word = pdt->cursec << 8 | pdt->track;
fprintf(stderr, "Trk/sec = %d/%d\n", pdt->track, pdt->cursec);
break;
case readD:
*word = *pdt->ptr++;
break;
default:
*word = 0;
}
break;
}
return CPU_OK;
} // tdisk_read
static CPU_RES tdisk_write(c_addr addr, d_word word) {
d_word offset = addr - TERAK_DISK_REG;
tdisk_t * pdt;
switch (offset) {
case 0: /* control port */
if (word) {
/* Print a message if something other than turning
* all drives off is requested
*/
// fprintf(stderr, _("Writing disk cmd, data %06o\n"), word);
}
selected = unit(word);
if (selected >= 0) {
pdt = &tdisks[selected];
if (pdt->inprogress)
return CPU_BUS_ERROR;
pdt->inprogress = word & enF;
pdt->cmd = cmd(word);
if (pdt->inprogress && word & intrF) switch (pdt->cmd) {
case nopD:
ev_register(TTY_PRI, cpu_service, TICK_RATE*100/25, 0250);
break;
case rtcD:
ev_register(TTY_PRI, cpu_service, TICK_RATE/50, 0250);
break;
default:
fprintf(stderr, "Interrupt requested\n");
ev_register(TTY_PRI, cpu_service, TICK_RATE/1000, 0250);
}
}
break;
case 2: /* data port */
fprintf(stderr, _("Writing disk data reg, data %06o\n"), word);
break;
}
return CPU_OK;
} // tdisk_write
static CPU_RES tdisk_bwrite(c_addr addr, d_byte byte) {
return tdisk_write(addr & ~1, byte);
} // tdisk_bwrite
pdp_qmap qmap_tdisk[] = { {
"terakdisk", "Terak disk",
TERAK_DISK_REG, TERAK_DISK_SIZE,
tdisk_init, tdisk_read, tdisk_write, tdisk_bwrite
} };