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sio.c
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sio.c
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/*
* sio.c - Serial I/O emulation
*
* Copyright (C) 1995-1998 David Firth
* Copyright (C) 1998-2008 Atari800 development team (see DOC/CREDITS)
*
* This file is part of the Atari800 emulator project which emulates
* the Atari 400, 800, 800XL, 130XE, and 5200 8-bit computers.
*
* Atari800 is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Atari800 is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Atari800; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "afile.h"
#include "antic.h" /* ANTIC_ypos */
#include "atari.h"
#include "binload.h"
#include "cassette.h"
#include "compfile.h"
#include "cpu.h"
#include "esc.h"
#include "log.h"
#include "memory.h"
#include "platform.h"
#include "pokey.h"
#include "pokeysnd.h"
#include "sio.h"
#include "util.h"
#ifndef BASIC
#include "statesav.h"
#endif
/* If ATR image is in double density (256 bytes per sector),
then the boot sectors (sectors 1-3) can be:
- logical (as seen by Atari) - 128 bytes in each sector
- physical (as stored on the disk) - 256 bytes in each sector.
Only the first half of sector is used for storing data, the rest is zero.
- SIO2PC (the type used by the SIO2PC program) - 3 * 128 bytes for data
of boot sectors, then 3 * 128 unused bytes (zero)
The XFD images in double density have either logical or physical
boot sectors. */
#define BOOT_SECTORS_LOGICAL 0
#define BOOT_SECTORS_PHYSICAL 1
#define BOOT_SECTORS_SIO2PC 2
static int boot_sectors_type[SIO_MAX_DRIVES];
static int image_type[SIO_MAX_DRIVES];
#define IMAGE_TYPE_XFD 0
#define IMAGE_TYPE_ATR 1
#define IMAGE_TYPE_PRO 2
static FILE *disk[SIO_MAX_DRIVES] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL };
static int sectorcount[SIO_MAX_DRIVES];
static int sectorsize[SIO_MAX_DRIVES];
/* these two are used by the 1450XLD parallel disk device */
int SIO_format_sectorcount[SIO_MAX_DRIVES];
int SIO_format_sectorsize[SIO_MAX_DRIVES];
static int io_success[SIO_MAX_DRIVES];
/* stores dup sector counter for PRO images */
typedef struct tagpro_additional_info_t {
int max_sector;
unsigned char *count;
} pro_additional_info_t;
static void *additional_info[SIO_MAX_DRIVES];
SIO_UnitStatus SIO_drive_status[SIO_MAX_DRIVES];
char SIO_filename[SIO_MAX_DRIVES][FILENAME_MAX];
Util_tmpbufdef(static, sio_tmpbuf[SIO_MAX_DRIVES])
int SIO_last_op;
int SIO_last_op_time = 0;
int SIO_last_drive;
int SIO_last_sector;
char SIO_status[256];
/* Serial I/O emulation support */
#define SIO_NoFrame (0x00)
#define SIO_CommandFrame (0x01)
#define SIO_StatusRead (0x02)
#define SIO_ReadFrame (0x03)
#define SIO_WriteFrame (0x04)
#define SIO_FinalStatus (0x05)
#define SIO_FormatFrame (0x06)
#define SIO_CasRead (0x60)
#define SIO_CasWrite (0x61)
static UBYTE CommandFrame[6];
static int CommandIndex = 0;
static UBYTE DataBuffer[256 + 3];
static int DataIndex = 0;
static int TransferStatus = SIO_NoFrame;
static int ExpectedBytes = 0;
int ignore_header_writeprotect = FALSE;
int SIO_Initialise(int *argc, char *argv[])
{
int i;
for (i = 0; i < SIO_MAX_DRIVES; i++) {
strcpy(SIO_filename[i], "Off");
SIO_drive_status[i] = SIO_OFF;
SIO_format_sectorsize[i] = 128;
SIO_format_sectorcount[i] = 720;
}
TransferStatus = SIO_NoFrame;
return TRUE;
}
/* umount disks so temporary files are deleted */
void SIO_Exit(void)
{
int i;
for (i = 1; i <= SIO_MAX_DRIVES; i++)
SIO_Dismount(i);
}
int SIO_Mount(int diskno, const char *filename, int b_open_readonly)
{
FILE *f = NULL;
SIO_UnitStatus status = SIO_READ_WRITE;
struct AFILE_ATR_Header header;
/* avoid overruns in SIO_filename[] */
if (strlen(filename) >= FILENAME_MAX)
return FALSE;
/* release previous disk */
SIO_Dismount(diskno);
/* open file */
if (!b_open_readonly)
f = Util_fopen(filename, "rb+", sio_tmpbuf[diskno - 1]);
if (f == NULL) {
f = Util_fopen(filename, "rb", sio_tmpbuf[diskno - 1]);
if (f == NULL)
return FALSE;
status = SIO_READ_ONLY;
}
/* read header */
if (fread(&header, 1, sizeof(struct AFILE_ATR_Header), f) != sizeof(struct AFILE_ATR_Header)) {
fclose(f);
return FALSE;
}
/* detect compressed image and uncompress */
switch (header.magic1) {
case 0xf9:
case 0xfa:
/* DCM */
{
FILE *f2 = Util_tmpopen(sio_tmpbuf[diskno - 1]);
if (f2 == NULL)
return FALSE;
Util_rewind(f);
if (!CompFile_DCMtoATR(f, f2)) {
Util_fclose(f2, sio_tmpbuf[diskno - 1]);
fclose(f);
return FALSE;
}
fclose(f);
f = f2;
}
Util_rewind(f);
if (fread(&header, 1, sizeof(struct AFILE_ATR_Header), f) != sizeof(struct AFILE_ATR_Header)) {
Util_fclose(f, sio_tmpbuf[diskno - 1]);
return FALSE;
}
status = SIO_READ_ONLY;
/* XXX: status = b_open_readonly ? SIO_READ_ONLY : SIO_READ_WRITE; */
break;
case 0x1f:
if (header.magic2 == 0x8b) {
/* ATZ/ATR.GZ, XFZ/XFD.GZ */
fclose(f);
f = Util_tmpopen(sio_tmpbuf[diskno - 1]);
if (f == NULL)
return FALSE;
if (!CompFile_ExtractGZ(filename, f)) {
Util_fclose(f, sio_tmpbuf[diskno - 1]);
return FALSE;
}
Util_rewind(f);
if (fread(&header, 1, sizeof(struct AFILE_ATR_Header), f) != sizeof(struct AFILE_ATR_Header)) {
Util_fclose(f, sio_tmpbuf[diskno - 1]);
return FALSE;
}
status = SIO_READ_ONLY;
/* XXX: status = b_open_readonly ? SIO_READ_ONLY : SIO_READ_WRITE; */
}
break;
default:
break;
}
boot_sectors_type[diskno - 1] = BOOT_SECTORS_LOGICAL;
if (header.magic1 == AFILE_ATR_MAGIC1 && header.magic2 == AFILE_ATR_MAGIC2) {
/* ATR (may be temporary from DCM or ATR/ATR.GZ) */
image_type[diskno - 1] = IMAGE_TYPE_ATR;
sectorsize[diskno - 1] = (header.secsizehi << 8) + header.secsizelo;
if (sectorsize[diskno - 1] != 128 && sectorsize[diskno - 1] != 256) {
Util_fclose(f, sio_tmpbuf[diskno - 1]);
return FALSE;
}
if (header.writeprotect != 0 && !ignore_header_writeprotect)
status = SIO_READ_ONLY;
/* ATR header contains length in 16-byte chunks. */
/* First compute number of 128-byte chunks
- it's number of sectors on single density disk */
sectorcount[diskno - 1] = ((header.hiseccounthi << 24)
+ (header.hiseccountlo << 16)
+ (header.seccounthi << 8)
+ header.seccountlo) >> 3;
/* Fix number of sectors if double density */
if (sectorsize[diskno - 1] == 256) {
if ((sectorcount[diskno - 1] & 1) != 0)
/* logical (128-byte) boot sectors */
sectorcount[diskno - 1] += 3;
else {
/* 256-byte boot sectors */
/* check if physical or SIO2PC: physical if there's
a non-zero byte in bytes 0x190-0x30f of the ATR file */
UBYTE buffer[0x180];
int i;
fseek(f, 0x190, SEEK_SET);
if (fread(buffer, 1, 0x180, f) != 0x180) {
Util_fclose(f, sio_tmpbuf[diskno - 1]);
return FALSE;
}
boot_sectors_type[diskno - 1] = BOOT_SECTORS_SIO2PC;
for (i = 0; i < 0x180; i++)
if (buffer[i] != 0) {
boot_sectors_type[diskno - 1] = BOOT_SECTORS_PHYSICAL;
break;
}
}
sectorcount[diskno - 1] >>= 1;
}
}
else {
int file_length = Util_flen(f);
/* check for PRO */
if ((file_length-16)%(128+12) == 0 &&
(header.magic1*256 + header.magic2 == (file_length-16)/(128+12)) &&
header.seccountlo == 'P') {
pro_additional_info_t *info;
/* .pro is read only for now */
if (!b_open_readonly) {
fclose(f);
f = Util_fopen(filename, "rb", sio_tmpbuf[diskno - 1]);
if (f == NULL)
return FALSE;
status = SIO_READ_ONLY;
}
image_type[diskno - 1] = IMAGE_TYPE_PRO;
sectorsize[diskno - 1] = 128;
if (file_length >= 1040*(128+12)+16) {
/* assume enhanced density */
sectorcount[diskno - 1] = 1040;
}
else {
/* assume single density */
sectorcount[diskno - 1] = 720;
}
info = Util_malloc(sizeof(pro_additional_info_t));
additional_info[diskno-1] = info;
info->count = Util_malloc(sectorcount[diskno - 1]);
memset(info->count, 0, sectorcount[diskno -1]);
info->max_sector = (file_length-16)/(128+12);
}
else {
/* XFD (may be temporary from XFZ/XFD.GZ) */
image_type[diskno - 1] = IMAGE_TYPE_XFD;
if (file_length <= (1040 * 128)) {
/* single density */
sectorsize[diskno - 1] = 128;
sectorcount[diskno - 1] = file_length >> 7;
}
else {
/* double density */
sectorsize[diskno - 1] = 256;
if ((file_length & 0xff) == 0) {
boot_sectors_type[diskno - 1] = BOOT_SECTORS_PHYSICAL;
sectorcount[diskno - 1] = file_length >> 8;
}
else
sectorcount[diskno - 1] = (file_length + 0x180) >> 8;
}
}
}
#ifdef DEBUG
Log_print("sectorcount = %d, sectorsize = %d",
sectorcount[diskno - 1], sectorsize[diskno - 1]);
#endif
SIO_format_sectorsize[diskno - 1] = sectorsize[diskno - 1];
SIO_format_sectorcount[diskno - 1] = sectorcount[diskno - 1];
strcpy(SIO_filename[diskno - 1], filename);
SIO_drive_status[diskno - 1] = status;
disk[diskno - 1] = f;
return TRUE;
}
void SIO_Dismount(int diskno)
{
if (disk[diskno - 1] != NULL) {
Util_fclose(disk[diskno - 1], sio_tmpbuf[diskno - 1]);
disk[diskno - 1] = NULL;
SIO_drive_status[diskno - 1] = SIO_NO_DISK;
strcpy(SIO_filename[diskno - 1], "Empty");
if (image_type[diskno - 1] == IMAGE_TYPE_PRO) {
free(((pro_additional_info_t *)additional_info[diskno-1])->count);
}
free(additional_info[diskno - 1]);
additional_info[diskno - 1] = 0;
}
}
void SIO_DisableDrive(int diskno)
{
SIO_Dismount(diskno);
SIO_drive_status[diskno - 1] = SIO_OFF;
strcpy(SIO_filename[diskno - 1], "Off");
}
void SIO_SizeOfSector(UBYTE unit, int sector, int *sz, ULONG *ofs)
{
int size;
ULONG offset;
int header_size = (image_type[unit] == IMAGE_TYPE_ATR ? 16 : 0);
if (BINLOAD_start_binloading) {
if (sz)
*sz = 128;
if (ofs)
*ofs = 0;
return;
}
if (image_type[unit] == IMAGE_TYPE_PRO) {
size = 128;
offset = 16 + (128+12)*(sector -1); /* returns offset of header */
}
else if (sector < 4) {
/* special case for first three sectors in ATR and XFD image */
size = 128;
offset = header_size + (sector - 1) * (boot_sectors_type[unit] == BOOT_SECTORS_PHYSICAL ? 256 : 128);
}
else {
size = sectorsize[unit];
offset = header_size + (boot_sectors_type[unit] == BOOT_SECTORS_LOGICAL ? 0x180 : 0x300) + (sector - 4) * size;
}
if (sz)
*sz = size;
if (ofs)
*ofs = offset;
}
static int SeekSector(int unit, int sector)
{
ULONG offset;
int size;
SIO_last_sector = sector;
sprintf(SIO_status, "%d: %d", unit + 1, sector);
SIO_SizeOfSector((UBYTE) unit, sector, &size, &offset);
fseek(disk[unit], offset, SEEK_SET);
return size;
}
/* Unit counts from zero up */
int SIO_ReadSector(int unit, int sector, UBYTE *buffer)
{
int size;
if (BINLOAD_start_binloading)
return BINLOAD_LoaderStart(buffer);
io_success[unit] = -1;
if (SIO_drive_status[unit] == SIO_OFF)
return 0;
if (disk[unit] == NULL)
return 'N';
if (sector <= 0 || sector > sectorcount[unit])
return 'E';
SIO_last_op = SIO_LAST_READ;
SIO_last_op_time = 1;
SIO_last_drive = unit + 1;
/* FIXME: what sector size did the user expect? */
size = SeekSector(unit, sector);
if (image_type[unit] == IMAGE_TYPE_PRO) {
pro_additional_info_t *info;
unsigned char *count;
info = (pro_additional_info_t *)additional_info[unit];
count = info->count;
fread(buffer, 1, 12, disk[unit]);
/* handle duplicate sectors */
if (buffer[5] != 0) {
int dupnum = count[sector];
#ifdef DEBUG_PRO
Log_print("duplicate sector:%d dupnum:%d",sector, dupnum);
#endif
count[sector] = (count[sector]+1) % (buffer[5]+1);
if (dupnum != 0) {
sector = sectorcount[unit] + buffer[6+dupnum];
/* can dupnum be 5? */
if (dupnum > 4 || sector <= 0 || sector > info->max_sector) {
Log_print("Error in .pro image: sector:%d dupnum:%d", sector, dupnum);
return 'E';
}
size = SeekSector(unit, sector);
/* read sector header */
fread(buffer, 1, 12, disk[unit]);
}
}
/* bad sector */
if (buffer[1] != 0xff) {
fread(buffer, 1, size, disk[unit]);
io_success[unit] = sector;
#ifdef DEBUG_PRO
Log_print("bad sector:%d", sector);
#endif
return 'E';
}
}
fread(buffer, 1, size, disk[unit]);
io_success[unit] = 0;
return 'C';
}
int SIO_WriteSector(int unit, int sector, const UBYTE *buffer)
{
int size;
io_success[unit] = -1;
if (SIO_drive_status[unit] == SIO_OFF)
return 0;
if (disk[unit] == NULL)
return 'N';
if (SIO_drive_status[unit] != SIO_READ_WRITE || sector <= 0 || sector > sectorcount[unit])
return 'E';
SIO_last_op = SIO_LAST_WRITE;
SIO_last_op_time = 1;
SIO_last_drive = unit + 1;
size = SeekSector(unit, sector);
fwrite(buffer, 1, size, disk[unit]);
io_success[unit] = 0;
return 'C';
}
int SIO_FormatDisk(int unit, UBYTE *buffer, int sectsize, int sectcount)
{
char fname[FILENAME_MAX];
int is_atr;
int save_boot_sectors_type;
int bootsectsize;
int bootsectcount;
FILE *f;
int i;
io_success[unit] = -1;
if (SIO_drive_status[unit] == SIO_OFF)
return 0;
if (disk[unit] == NULL)
return 'N';
if (SIO_drive_status[unit] != SIO_READ_WRITE)
return 'E';
/* Note formatting the disk can change size of the file.
There is no portable way to truncate the file at given position.
We have to close the "rb+" open file and open it in "wb" mode.
First get the information about the disk image, because we are going
to umount it. */
memcpy(fname, SIO_filename[unit], FILENAME_MAX);
is_atr = (image_type[unit] == IMAGE_TYPE_ATR);
save_boot_sectors_type = boot_sectors_type[unit];
bootsectsize = 128;
if (sectsize == 256 && save_boot_sectors_type != BOOT_SECTORS_LOGICAL)
bootsectsize = 256;
bootsectcount = sectcount < 3 ? sectcount : 3;
/* Umount the file and open it in "wb" mode (it will truncate the file) */
SIO_Dismount(unit + 1);
f = fopen(fname, "wb");
if (f == NULL) {
Log_print("SIO_FormatDisk: failed to open %s for writing", fname);
return 'E';
}
/* Write ATR header if necessary */
if (is_atr) {
struct AFILE_ATR_Header header;
ULONG disksize = (bootsectsize * bootsectcount + sectsize * (sectcount - bootsectcount)) >> 4;
memset(&header, 0, sizeof(header));
header.magic1 = AFILE_ATR_MAGIC1;
header.magic2 = AFILE_ATR_MAGIC2;
header.secsizelo = (UBYTE) sectsize;
header.secsizehi = (UBYTE) (sectsize >> 8);
header.seccountlo = (UBYTE) disksize;
header.seccounthi = (UBYTE) (disksize >> 8);
header.hiseccountlo = (UBYTE) (disksize >> 16);
header.hiseccounthi = (UBYTE) (disksize >> 24);
fwrite(&header, 1, sizeof(header), f);
}
/* Write boot sectors */
memset(buffer, 0, sectsize);
for (i = 1; i <= bootsectcount; i++)
fwrite(buffer, 1, bootsectsize, f);
/* Write regular sectors */
for ( ; i <= sectcount; i++)
fwrite(buffer, 1, sectsize, f);
/* Close file and mount the disk back */
fclose(f);
SIO_Mount(unit + 1, fname, FALSE);
/* We want to keep the current PHYSICAL/SIO2PC boot sectors type
(since the image is blank it can't be figured out by SIO_Mount) */
if (bootsectsize == 256)
boot_sectors_type[unit] = save_boot_sectors_type;
/* Return information for Atari (buffer filled with ff's - no bad sectors) */
memset(buffer, 0xff, sectsize);
io_success[unit] = 0;
return 'C';
}
/* Set density and number of sectors
This function is used before the format (0x21) command
to set how the disk will be formatted.
Note this function does *not* affect the currently attached disk
(previously sectorsize/sectorcount were used which could result in
a corrupted image).
*/
int SIO_WriteStatusBlock(int unit, const UBYTE *buffer)
{
int size;
#ifdef DEBUG
Log_print("Write Status-Block: %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
buffer[0], buffer[1], buffer[2], buffer[3],
buffer[4], buffer[5], buffer[6], buffer[7],
buffer[8], buffer[9], buffer[10], buffer[11]);
#endif
if (SIO_drive_status[unit] == SIO_OFF)
return 0;
/* We only care about the density and the sector count here.
Setting everything else right here seems to be non-sense.
I'm not sure about this density settings, my XF551
honors only the sector size and ignores the density */
size = buffer[6] * 256 + buffer[7];
if (size == 128 || size == 256)
SIO_format_sectorsize[unit] = size;
/* Note that the number of heads are minus 1 */
SIO_format_sectorcount[unit] = buffer[0] * (buffer[2] * 256 + buffer[3]) * (buffer[4] + 1);
if (SIO_format_sectorcount[unit] < 1 || SIO_format_sectorcount[unit] > 65535)
SIO_format_sectorcount[unit] = 720;
return 'C';
}
int SIO_ReadStatusBlock(int unit, UBYTE *buffer)
{
UBYTE tracks;
UBYTE heads;
int spt;
if (SIO_drive_status[unit] == SIO_OFF)
return 0;
/* default to 1 track, 1 side for non-standard images */
tracks = 1;
heads = 1;
spt = sectorcount[unit];
if (spt % 40 == 0) {
/* standard disk */
tracks = 40;
spt /= 40;
if (spt > 26 && spt % 2 == 0) {
/* double-sided */
heads = 2;
spt >>= 1;
if (spt > 26 && spt % 2 == 0) {
/* double-sided, 80 tracks */
tracks = 80;
spt >>= 1;
}
}
}
buffer[0] = tracks; /* # of tracks */
buffer[1] = 1; /* step rate */
buffer[2] = (UBYTE) (spt >> 8); /* sectors per track. HI byte */
buffer[3] = (UBYTE) spt; /* sectors per track. LO byte */
buffer[4] = (UBYTE) (heads - 1); /* # of heads minus 1 */
/* FM for single density, MFM otherwise */
buffer[5] = (sectorsize[unit] == 128 && sectorcount[unit] <= 720) ? 0 : 4;
buffer[6] = (UBYTE) (sectorsize[unit] >> 8); /* bytes per sector. HI byte */
buffer[7] = (UBYTE) sectorsize[unit]; /* bytes per sector. LO byte */
buffer[8] = 1; /* drive is online */
buffer[9] = 192; /* transfer speed, whatever this means */
buffer[10] = 0;
buffer[11] = 0;
return 'C';
}
/*
Status Request from Atari 400/800 Technical Reference Notes
DVSTAT + 0 Command Status
DVSTAT + 1 Hardware Status
DVSTAT + 2 Timeout
DVSTAT + 3 Unused
Command Status Bits
Bit 0 = 1 indicates an invalid command frame was received
Bit 1 = 1 indicates an invalid data frame was received
Bit 2 = 1 indicates that last read/write operation was unsuccessful
Bit 3 = 1 indicates that the diskette is write protected
Bit 4 = 1 indicates active/standby
plus
Bit 5 = 1 indicates double density
Bit 7 = 1 indicates dual density disk (1050 format)
*/
int SIO_DriveStatus(int unit, UBYTE *buffer)
{
if (BINLOAD_start_binloading) {
buffer[0] = 16 + 8;
buffer[1] = 255;
buffer[2] = 1;
buffer[3] = 0 ;
return 'C';
}
if (SIO_drive_status[unit] == SIO_OFF)
return 0;
/* .PRO contains status information in the sector header */
if (io_success[unit] != 0 && image_type[unit] == IMAGE_TYPE_PRO) {
int sector = io_success[unit];
SeekSector(unit, sector);
fread(buffer, 1, 4, disk[unit]);
return 'C';
}
buffer[0] = 16; /* drive active */
buffer[1] = disk[unit] != NULL ? 255 /* WD 177x OK */ : 127 /* no disk */;
if (io_success[unit] != 0)
buffer[0] |= 4; /* failed RW-operation */
if (SIO_drive_status[unit] == SIO_READ_ONLY)
buffer[0] |= 8; /* write protection */
if (SIO_format_sectorsize[unit] == 256)
buffer[0] |= 32; /* double density */
if (SIO_format_sectorcount[unit] == 1040)
buffer[0] |= 128; /* 1050 enhanced density */
buffer[2] = 1;
buffer[3] = 0;
return 'C';
}
#ifndef NO_SECTOR_DELAY
/* A hack for the "Overmind" demo. This demo verifies if sectors aren't read
faster than with a typical disk drive. We introduce a delay
of SECTOR_DELAY scanlines between successive reads of sector 1. */
#define SECTOR_DELAY 3200
static int delay_counter = 0;
static int last_ypos = 0;
#endif
/* SIO patch emulation routine */
void SIO_Handler(void)
{
int sector = MEMORY_dGetWordAligned(0x30a);
UBYTE unit = (MEMORY_dGetByte(0x300) + MEMORY_dGetByte(0x301) + 0xff ) - 0x31;
UBYTE result = 0x00;
UWORD data = MEMORY_dGetWordAligned(0x304);
int length = MEMORY_dGetWordAligned(0x308);
int realsize = 0;
int cmd = MEMORY_dGetByte(0x302);
if ((unsigned int)MEMORY_dGetByte(0x300) + (unsigned int)MEMORY_dGetByte(0x301) > 0xff) {
/* carry */
unit++;
}
/* A real atari just adds the bytes and 0xff. The result could wrap.*/
/* XL OS: E99D: LDA $0300 ADC $0301 ADC #$FF STA 023A */
/* Disk 1 is ASCII '1' = 0x31 etc */
/* Disk 1 -> unit = 0 */
if (MEMORY_dGetByte(0x300) != 0x60 && unit < SIO_MAX_DRIVES) { /* UBYTE range ! */
#ifdef DEBUG
Log_print("SIO disk command is %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
cmd, MEMORY_dGetByte(0x303), MEMORY_dGetByte(0x304), MEMORY_dGetByte(0x305), MEMORY_dGetByte(0x306),
MEMORY_dGetByte(0x308), MEMORY_dGetByte(0x309), MEMORY_dGetByte(0x30a), MEMORY_dGetByte(0x30b),
MEMORY_dGetByte(0x30c), MEMORY_dGetByte(0x30d));
#endif
switch (cmd) {
case 0x4e: /* Read Status Block */
if (12 == length) {
result = SIO_ReadStatusBlock(unit, DataBuffer);
if (result == 'C')
MEMORY_CopyToMem(DataBuffer, data, 12);
}
else
result = 'E';
break;
case 0x4f: /* Write Status Block */
if (12 == length) {
MEMORY_CopyFromMem(data, DataBuffer, 12);
result = SIO_WriteStatusBlock(unit, DataBuffer);
}
else
result = 'E';
break;
case 0x50: /* Write */
case 0x57:
case 0xD0: /* xf551 hispeed */
case 0xD7:
SIO_SizeOfSector(unit, sector, &realsize, NULL);
if (realsize == length) {
MEMORY_CopyFromMem(data, DataBuffer, realsize);
result = SIO_WriteSector(unit, sector, DataBuffer);
}
else
result = 'E';
break;
case 0x52: /* Read */
case 0xD2: /* xf551 hispeed */
#ifndef NO_SECTOR_DELAY
if (sector == 1) {
if (delay_counter > 0) {
if (last_ypos != ANTIC_ypos) {
last_ypos = ANTIC_ypos;
delay_counter--;
}
CPU_regPC = 0xe459; /* stay at SIO patch */
return;
}
delay_counter = SECTOR_DELAY;
}
else {
delay_counter = 0;
}
#endif
SIO_SizeOfSector(unit, sector, &realsize, NULL);
if (realsize == length) {
result = SIO_ReadSector(unit, sector, DataBuffer);
if (result == 'C')
MEMORY_CopyToMem(DataBuffer, data, realsize);
}
else
result = 'E';
break;
case 0x53: /* Status */
if (4 == length) {
result = SIO_DriveStatus(unit, DataBuffer);
MEMORY_CopyToMem(DataBuffer, data, 4);
}
else
result = 'E';
break;
/*case 0x66:*/ /* US Doubler Format - I think! */
case 0x21: /* Format Disk */
case 0xA1: /* xf551 hispeed */
realsize = SIO_format_sectorsize[unit];
if (realsize == length) {
result = SIO_FormatDisk(unit, DataBuffer, realsize, SIO_format_sectorcount[unit]);
if (result == 'C')
MEMORY_CopyToMem(DataBuffer, data, realsize);
}
else {
/* there are programs which send the format-command but don't wait for the result (eg xf-tools) */
SIO_FormatDisk(unit, DataBuffer, realsize, SIO_format_sectorcount[unit]);
result = 'E';
}
break;
case 0x22: /* Enhanced Density Format */
case 0xA2: /* xf551 hispeed */
realsize = 128;
if (realsize == length) {
result = SIO_FormatDisk(unit, DataBuffer, 128, 1040);
if (result == 'C')
MEMORY_CopyToMem(DataBuffer, data, realsize);
}
else {
SIO_FormatDisk(unit, DataBuffer, 128, 1040);
result = 'E';
}
break;
default:
result = 'N';
}
}
/* cassette i/o */
else if (MEMORY_dGetByte(0x300) == 0x60) {
int storagelength = 0;
UBYTE gaps = MEMORY_dGetByte(0x30b);
switch (cmd){
case 0x52: /* read */
/* set expected Gap */
CASSETTE_AddGap(gaps == 0 ? 2000 : 160);
SIO_last_op = SIO_LAST_READ;
SIO_last_drive = 0x61;
SIO_last_op_time = 0x10;
/* get record from storage medium */
storagelength = CASSETTE_Read();
if (storagelength - 1 != length) /* includes -1 as error */
result = 'E';
else
result = 'C';
/* check checksum */
if (CASSETTE_buffer[length] != SIO_ChkSum(CASSETTE_buffer, length))
result = 'E';
/* if all went ok, copy to Atari */
if (result == 'C')
MEMORY_CopyToMem(CASSETTE_buffer, data, length);
break;
case 0x57: /* write */
SIO_last_op = SIO_LAST_WRITE;
SIO_last_drive = 0x61;
SIO_last_op_time = 0x10;
/* put record into buffer */
MEMORY_CopyFromMem(data, CASSETTE_buffer, length);
/* eval checksum over buffer data */
CASSETTE_buffer[length] = SIO_ChkSum(CASSETTE_buffer, length);
/* add pregap length */
CASSETTE_AddGap(gaps == 0 ? 3000 : 260);
/* write full record to storage medium */
storagelength = CASSETTE_Write(length + 1);
if (storagelength - 1 != length) /* includes -1 as error */
result = 'E';
else
result = 'C';
break;
default:
result = 'N';
}
}
switch (result) {
case 0x00: /* Device disabled, generate timeout */
CPU_regY = 138;
CPU_SetN;
break;
case 'A': /* Device acknowledge */
case 'C': /* Operation complete */
CPU_regY = 1;
CPU_ClrN;
break;
case 'N': /* Device NAK */
CPU_regY = 144;
CPU_SetN;
break;
case 'E': /* Device error */
default:
CPU_regY = 146;
CPU_SetN;
break;
}
CPU_regA = 0; /* MMM */
MEMORY_dPutByte(0x0303, CPU_regY);
MEMORY_dPutByte(0x42,0);
CPU_SetC;
}
UBYTE SIO_ChkSum(const UBYTE *buffer, int length)
{
#if 0
/* old, less efficient version */
int i;
int checksum = 0;
for (i = 0; i < length; i++, buffer++) {
checksum += *buffer;
while (checksum > 255)
checksum -= 255;
}
#else
int checksum = 0;
while (--length >= 0)
checksum += *buffer++;
do
checksum = (checksum & 0xff) + (checksum >> 8);
while (checksum > 255);
#endif
return checksum;
}
static UBYTE Command_Frame(void)
{
int unit;
int sector;
int realsize;
sector = CommandFrame[2] | (((UWORD) CommandFrame[3]) << 8);
unit = CommandFrame[0] - '1';
if (unit < 0 || unit >= SIO_MAX_DRIVES) {
/* Unknown device */
Log_print("Unknown command frame: %02x %02x %02x %02x %02x",
CommandFrame[0], CommandFrame[1], CommandFrame[2],
CommandFrame[3], CommandFrame[4]);
TransferStatus = SIO_NoFrame;
return 0;
}
switch (CommandFrame[1]) {
case 0x4e: /* Read Status */
#ifdef DEBUG
Log_print("Read-status frame: %02x %02x %02x %02x %02x",
CommandFrame[0], CommandFrame[1], CommandFrame[2],
CommandFrame[3], CommandFrame[4]);
#endif
DataBuffer[0] = SIO_ReadStatusBlock(unit, DataBuffer + 1);
DataBuffer[13] = SIO_ChkSum(DataBuffer + 1, 12);
DataIndex = 0;
ExpectedBytes = 14;
TransferStatus = SIO_ReadFrame;
POKEY_DELAYED_SERIN_IRQ = SIO_SERIN_INTERVAL;
return 'A';
case 0x4f: /* Write status */
#ifdef DEBUG
Log_print("Write-status frame: %02x %02x %02x %02x %02x",
CommandFrame[0], CommandFrame[1], CommandFrame[2],
CommandFrame[3], CommandFrame[4]);
#endif
ExpectedBytes = 13;
DataIndex = 0;
TransferStatus = SIO_WriteFrame;
return 'A';
case 0x50: /* Write */
case 0x57:
case 0xD0: /* xf551 hispeed */
case 0xD7:
#ifdef DEBUG
Log_print("Write-sector frame: %02x %02x %02x %02x %02x",
CommandFrame[0], CommandFrame[1], CommandFrame[2],
CommandFrame[3], CommandFrame[4]);
#endif
SIO_SizeOfSector((UBYTE) unit, sector, &realsize, NULL);
ExpectedBytes = realsize + 1;
DataIndex = 0;
TransferStatus = SIO_WriteFrame;
SIO_last_op = SIO_LAST_WRITE;
SIO_last_op_time = 10;
SIO_last_drive = unit + 1;
return 'A';
case 0x52: /* Read */
case 0xD2: /* xf551 hispeed */
#ifdef DEBUG
Log_print("Read-sector frame: %02x %02x %02x %02x %02x",
CommandFrame[0], CommandFrame[1], CommandFrame[2],
CommandFrame[3], CommandFrame[4]);
#endif
SIO_SizeOfSector((UBYTE) unit, sector, &realsize, NULL);
DataBuffer[0] = SIO_ReadSector(unit, sector, DataBuffer + 1);
DataBuffer[1 + realsize] = SIO_ChkSum(DataBuffer + 1, realsize);
DataIndex = 0;
ExpectedBytes = 2 + realsize;
TransferStatus = SIO_ReadFrame;
/* wait longer before confirmation because bytes could be lost */
/* before the buffer was set (see $E9FB & $EA37 in XL-OS) */
POKEY_DELAYED_SERIN_IRQ = SIO_SERIN_INTERVAL << 2;
#ifndef NO_SECTOR_DELAY
if (sector == 1) {
POKEY_DELAYED_SERIN_IRQ += delay_counter;
delay_counter = SECTOR_DELAY;
}
else {
delay_counter = 0;
}
#endif
SIO_last_op = SIO_LAST_READ;
SIO_last_op_time = 10;
SIO_last_drive = unit + 1;
return 'A';
case 0x53: /* Status */
#ifdef DEBUG
Log_print("Status frame: %02x %02x %02x %02x %02x",
CommandFrame[0], CommandFrame[1], CommandFrame[2],
CommandFrame[3], CommandFrame[4]);
#endif
DataBuffer[0] = SIO_DriveStatus(unit, DataBuffer + 1);
DataBuffer[1 + 4] = SIO_ChkSum(DataBuffer + 1, 4);
DataIndex = 0;
ExpectedBytes = 6;