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tape.c
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/*
** Oricutron
** Copyright (C) 2009-2014 Peter Gordon
**
** This program 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, version 2
** of the License.
**
** This program 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 this program; if not, write to the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
**
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "system.h"
#include "6502.h"
#include "via.h"
#include "8912.h"
#include "gui.h"
#include "disk.h"
#include "monitor.h"
#include "6551.h"
#include "machine.h"
#include "joystick.h"
#include "filereq.h"
#include "tape.h"
#include "msgbox.h"
#ifdef WWW
#include <emscripten.h>
#endif
extern char tapefile[], tapepath[];
extern SDL_bool refreshtape;
char tmptapename[4096];
extern char filetmp[];
// Pop-up the name of the currently inserted tape
// image file (or an eject symbol if no tape image).
void tape_popup( struct machine *oric )
{
char tmp[40];
if( !oric->tapename[0] )
{
// Eject symbol
do_popup( oric, "\x0f\x10\x13" );
return;
}
// Tape image name
sprintf( tmp, "\x0f\x10""%c %-16s", oric->tapemotor ? 18 : 17, oric->tapename );
do_popup( oric, tmp );
}
void toggletapecap( struct machine *oric, struct osdmenuitem *mitem, int dummy )
{
char ortheader[] = { 'O', 'R', 'T', 0 }; // Oric Raw Tape, Version 0
/* If capturing, stop */
if( oric->tapecap )
{
fclose( oric->tapecap );
#ifdef WWW
// sync from memory state to persisted
EM_ASM(
FS.syncfs(function (err) {
assert(!err);
});
);
#endif
oric->tapecap = NULL;
mitem->name = "Save tape output...";
refreshtape = SDL_TRUE;
return;
}
/* Otherwise, prompt for the file to capture */
if( !filerequester( oric, "Capture tape output", tapepath, tmptapename, FR_TAPESAVEORT ) )
{
// Never mind
return;
}
if( tmptapename[0] == 0 ) return;
/* If it ends in ".tap", we need to change it to ".ort", because
we're capturing real signals here folks! */
if( (strlen(tmptapename)>3) && (strcasecmp(&tmptapename[strlen(tmptapename)-4], ".tap")==0) )
tmptapename[strlen(tmptapename)-4] = 0;
/* Add .ort extension, if necessary */
if( (strlen(tmptapename)<4) || (strcasecmp(&tmptapename[strlen(tmptapename)-4], ".ort")!=0) )
strncat(tmptapename, ".ort", 4095);
tmptapename[4095] = 0;
joinpath( tapepath, tmptapename );
/* Open the file */
oric->tapecap = fopen( filetmp, "wb" );
if( !oric->tapecap )
{
/* Oh well */
msgbox( oric, MSGBOX_OK, "Unable to create file" );
return;
}
/* Write header */
fwrite( ortheader, 4, 1, oric->tapecap);
/* Counter reset */
oric->tapecapcount = -1;
oric->tapecaplastbit = (oric->via.orb&oric->via.ddrb)>>7;
/* Update menu */
mitem->name = "Stop tape recording";
refreshtape = SDL_TRUE;
}
/* When we're loading a .tap file (or a non-raw section of a .ort file),
** we have to do 2 things... First, we have to elongate the leader so the ROM
** can see it, and secondly we have to add a delay after the header so that the
** tape isn't several bytes into the program when the rom is ready to start
** reading it.
**
** Only call it when you think you're at a tape leader since it doesn't do many
** sanity checks.
*/
void tape_setup_header( struct machine *oric )
{
int i;
oric->tapedupbytes = 0;
oric->tapehdrend = 0;
if( oric->tapebuf[oric->tapeoffs] != 0x16 )
return;
/* Does it look like a header? */
for( i=0; oric->tapebuf[oric->tapeoffs+i]==0x16; i++ )
{
if( (oric->tapeoffs+i) >= oric->tapelen )
return;
}
if( ( i < 3 ) || ( oric->tapebuf[oric->tapeoffs+i] != 0x24 ) )
return;
i++;
if( (oric->tapeoffs+i+9) >= oric->tapelen )
return;
i+=9;
while( oric->tapebuf[oric->tapeoffs+i] != 0 )
{
if( (oric->tapeoffs+i) >= oric->tapelen )
return;
i++;
}
i++;
oric->tapedupbytes = 80;
oric->tapehdrend = oric->tapeoffs+i;
}
void tape_orbchange( struct via *via )
{
struct machine *oric = via->oric;
unsigned char buffer[4], tapebit, bufwrite;
unsigned int count;
/* Capturing tape output? */
if( !oric->tapecap ) return;
/* Saving a tap section? */
if( oric->tapecap == oric->tsavf ) return;
tapebit = (via->orb & via->ddrb) >> 7;
if( tapebit == oric->tapecaplastbit ) return;
oric->tapecaplastbit = tapebit;
/* Were we waiting for the first toggle? */
if( oric->tapecapcount < 0 )
{
/* Well, we found it */
oric->tapecapcount = 0;
fputc( tapebit, oric->tapecap );
return;
}
count = (oric->tapecapcount>>1);
if( count < 0xfc )
{
buffer[0] = count;
bufwrite = 1;
}
else if( count < 0x100 )
{
buffer[0] = 0xfc;
buffer[1] = count;
bufwrite = 2;
}
else if( count < 0x10000 )
{
buffer[0] = 0xfd;
buffer[1] = (count>>8)&0xff;
buffer[2] = count&0xff;
bufwrite = 3;
}
else
{
buffer[0] = 0xfd;
buffer[1] = 0xff;
buffer[2] = 0xff;
bufwrite = 3;
}
fwrite( buffer, bufwrite, 1, oric->tapecap );
oric->tapecapcount = 0;
}
// Set the tape motor on or off
void tape_setmotor( struct machine *oric, SDL_bool motoron )
{
if( motoron == oric->tapemotor )
return;
// Refresh the tape status icon in the status bar
refreshtape = SDL_TRUE;
// "Real" tape emulation?
if( ( !oric->tapeturbo ) || ( !oric->pch_tt_available ) )
{
if( ( !oric->rawtape ) || ( oric->tapeoffs < oric->nonrawend ) )
{
// If we're stopping part way through a byte, just move
// the current position on to the start of the next byte
if( !motoron )
{
if( oric->tapebit > 0 )
oric->tapeoffs++;
oric->tapebit = 0;
}
// If we're starting the tape motor and the tape
// is at a sync header, generate a bunch of dummy
// sync bytes. This makes the Oric Atmos welcome tape
// work without turbo tape enabled, for example.
if( ( motoron ) &&
( oric->tapebuf ) &&
( oric->tapeoffs < oric->tapelen ) &&
( oric->tapebuf[oric->tapeoffs] == 0x16 ) )
{
tape_setup_header(oric);
}
}
}
// Set the new status and do a popup
oric->tapemotor = motoron;
if( oric->tapename[0] ) tape_popup( oric );
}
// Free up the current tape image
void tape_eject( struct machine *oric )
{
if( oric->tapebuf ) free( oric->tapebuf );
oric->tapebuf = NULL;
oric->tapelen = 0;
oric->tapename[0] = 0;
tape_popup( oric );
refreshtape = SDL_TRUE;
}
void tape_next_raw_count( struct machine *oric )
{
unsigned int n;
int nonrawend;
if( oric->tapeoffs >= oric->tapelen )
{
if( oric->nonrawend != oric->tapelen )
oric->tapehitend = 3;
return;
}
n = oric->tapebuf[oric->tapeoffs++];
if (n < 0xfc)
{
oric->tapecount = n<<1;
return;
}
switch (n)
{
case 0xff: // non-raw section
if( oric->tapeoffs >= (oric->tapelen-1) )
{
oric->tapeoffs = oric->tapelen;
oric->tapehitend = 3;
return;
}
nonrawend = ((oric->tapebuf[oric->tapeoffs]<<8)|oric->tapebuf[oric->tapeoffs+1]) + oric->tapeoffs+2;
if( nonrawend > oric->tapelen )
{
oric->tapeoffs = oric->tapelen;
oric->tapehitend = 3;
return;
}
oric->nonrawend = nonrawend;
oric->tapeoffs += 2;
oric->tapebit = 0;
oric->tapecount = 2;
oric->tapeout = 0;
tape_setup_header( oric );
return;
case 0xfc:
if( oric->tapeoffs >= oric->tapelen )
{
oric->tapehitend = 3;
return;
}
oric->tapecount = oric->tapebuf[oric->tapeoffs++] << 1;
return;
case 0xfd:
if( oric->tapeoffs >= (oric->tapelen-1) )
{
oric->tapeoffs = oric->tapelen;
oric->tapehitend = 3;
return;
}
oric->tapecount = (oric->tapebuf[oric->tapeoffs]<<9)|(oric->tapebuf[oric->tapeoffs+1]<<1);
oric->tapeoffs += 2;
return;
}
// Invalid data
oric->tapeoffs = oric->tapelen;
oric->tapehitend = 3;
}
// Rewind to the start of the tape
void tape_rewind( struct machine *oric )
{
oric->nonrawend = 0;
if( oric->rawtape )
{
oric->tapeout = oric->tapebuf[4];
via_write_CB1( &oric->via, oric->tapeout );
oric->tapeoffs = 5;
tape_next_raw_count( oric );
}
else
{
oric->tapeoffs = 0;
oric->tapebit = 0;
oric->tapecount = 2;
oric->tapeout = 0;
oric->tapedupbytes = 0;
if( oric->tapebuf )
tape_setup_header( oric );
}
oric->tapehitend = 0;
oric->tapedelay = 0;
refreshtape = SDL_TRUE;
}
// This is used by the "tapsections" function. It returns the next time
// value from an ort buffer, or -1 for invalid (or if an existing tapsection
// is found)
static int next_ort_value( unsigned char *ortdata, int *offset, int end, SDL_bool *anytapsec )
{
int val=0, skip;
while ((*offset) < end)
{
switch (ortdata[*offset])
{
case 0xfc:
if ((*offset) >= (end-1)) return 0;
val = ortdata[(*offset)+1];
(*offset) += 2;
return val;
case 0xfd:
if ((*offset) >= (end-2)) return 0;
val = (ortdata[(*offset)+1]<<8)|ortdata[(*offset)+2];
(*offset) += 3;
return val;
case 0xfe:
return 0;
case 0xff:
if ((*offset) >= (end-2)) return 0;
skip = (ortdata[(*offset)+1]<<8)|ortdata[(*offset)+2];
(*offset)+=3;
if ((*offset) >= (end-skip)) return 0;
(*offset)+=skip;
(*anytapsec) = SDL_TRUE;
break;
default:
return ortdata[(*offset)++];
}
}
return 0;
}
enum
{
TAPSEC_STATE_SEARCH = 0,
TAPSEC_STATE_LEADER,
TAPSEC_STATE_FINDHEADER,
TAPSEC_STATE_HEADER,
TAPSEC_STATE_FILENAME,
TAPSEC_STATE_FINDDATA,
TAPSEC_STATE_DATA
};
static int validbyte(int accum)
{
int i, parity = 0;
if ((accum&3)!=1) return 0;
for (i=4; i!=0x800; i<<=1)
if (accum&i) parity ^= 1;
return parity;
}
// This converts oric standard encoded waveforms to decoded TAP sections
static int tapsections( unsigned char *ortbuf, int ortbuflen, unsigned char *scratch, SDL_bool slow )
{
int ort_offs, tapebit, ort_val, cyccount;
int accum, state, thisbit, leaderstart=0, leadercount=0;
int last_offsets[20], i, bitcount, tapbytes=0;
int data_bytes=0, slow0s=0, slow1s=0;
SDL_bool anytapsec = SDL_FALSE;
ort_offs = 4;
tapebit = ortbuf[ort_offs++];
cyccount = 0;
state = TAPSEC_STATE_SEARCH;
accum = 0;
bitcount = 0;
for (i=0; i<20; i++)
last_offsets[i] = 5;
// Loop through the ORT data
while (ort_offs < ortbuflen)
{
// Shuffle the offset array
for (i=0; i<19; i++)
last_offsets[i] = last_offsets[i+1];
last_offsets[19] = ort_offs;
ort_val = next_ort_value(ortbuf, &ort_offs, ortbuflen, &anytapsec);
// Invalid ORT data?
if (ort_val < 1) return ortbuflen;
// Count these cycles
cyccount += ort_val;
// Invert the tape input
tapebit ^= 1;
// Rising edge?
if (tapebit)
{
// smaller than 100? filter it out
if (cyccount < 100)
continue;
// Convert to 1/0
thisbit = TIME_TO_BIT(cyccount);
// Seen a value that is outside the bounds of Oric standard encoding?
if (thisbit == -1)
{
// if ((state != TAPSEC_STATE_SEARCH) || (slow0s>0) || (slow1s>0))
// {
// if (cyccount < TAPE_DECODE_1_MIN) printf("%d is too fast\n", cyccount);
// if (cyccount > TAPE_DECODE_0_MAX) printf("%d is too slow\n", cyccount);
// fflush(stdout);
// }
state = TAPSEC_STATE_SEARCH;
cyccount = 0;
accum = 0;
slow1s = 0;
slow0s = 0;
}
else
{
// Slow mode?
if (slow)
{
if (thisbit==1)
{
slow1s++;
slow0s=0;
if (slow1s != 2)
{
if (slow1s >= 8)
slow1s = 0;
cyccount=0;
continue;
}
}
else
{
slow0s++;
slow1s=0;
if (slow0s != 2)
{
if (slow0s >= 4)
slow0s = 0;
cyccount=0;
continue;
}
}
}
// Accumulate this bit
accum = (accum>>1) | (thisbit<<10);
// What are we doing?
switch (state)
{
case TAPSEC_STATE_SEARCH:
// Look for 0x058 (0x16 encoded with start bit and parity)
if ((accum&0x7fe) == 0x58)
{
// printf("Seen 0x16 @ %d\n", ort_offs);
// fflush(stdout);
leaderstart = last_offsets[8];
leadercount = 1;
state = TAPSEC_STATE_LEADER;
bitcount = 0;
}
else if (validbyte(accum))
{
// printf("Saw %02X @ %d\n", (accum>>2)&0xff, ort_offs);
// fflush(stdout);
}
break;
case TAPSEC_STATE_LEADER:
bitcount = (bitcount+1)%14;
if ((bitcount==13)&&validbyte(accum)) bitcount = 0;
if (!bitcount)
{
// printf("Byte @ %d is %03x\n", ort_offs, accum&0x7fe);
// fflush(stdout);
if ((accum&0x7fe) != 0x58)
{
// printf("Which is NOT 0x58 :-(\n");
state = TAPSEC_STATE_SEARCH;
cyccount = 0;
break;
}
leadercount++;
if (leadercount==4)
{
state = TAPSEC_STATE_FINDHEADER;
break;
}
}
break;
case TAPSEC_STATE_FINDHEADER:
bitcount = (bitcount+1)%14;
if ((bitcount==13)&&validbyte(accum)) bitcount = 0;
if (!bitcount)
{
// printf("Byte @ %d is %03x\n", ort_offs, accum&0x7fe);
// fflush(stdout);
if ((accum&0x7fe) == 0x490) // 0x24 fully encoded
{
// printf("At the header...\n");
// fflush(stdout);
scratch[0] = 0x16;
scratch[1] = 0x16;
scratch[2] = 0x16;
scratch[3] = 0x24;
tapbytes = 4;
state = TAPSEC_STATE_HEADER;
}
}
break;
case TAPSEC_STATE_HEADER:
bitcount = (bitcount+1)%14;
if ((bitcount==13)&&validbyte(accum)) bitcount = 0;
if (!bitcount)
{
// printf("Byte @ %d is %03x (%02X)\n", ort_offs, accum&0x7fe, (accum>>2)&0xff);
// fflush(stdout);
scratch[tapbytes++] = (accum>>2)&0xff;
if (tapbytes == 13)
{
int load_start, load_end;
load_start = (scratch[10]<<8)|scratch[11];
load_end = (scratch[ 8]<<8)|scratch[ 9];
// printf("Load start = %04X, Load end = %04X\n", load_start, load_end);
// fflush(stdout);
if (load_end <= load_start)
{
state = TAPSEC_STATE_SEARCH;
cyccount = 0;
break;
}
data_bytes = (load_end-load_start)+1;
state = TAPSEC_STATE_FILENAME;
// printf("Lets try and load %d bytes!\n", data_bytes);
// fflush(stdout);
}
}
break;
case TAPSEC_STATE_FILENAME:
bitcount = (bitcount+1)%14;
if ((bitcount==13)&&validbyte(accum)) bitcount = 0;
if (!bitcount)
{
// printf("Filename byte = %03x (%02x) %c\n", accum&0x7fe, (accum>>2)&0xff, (accum>>2)&0xff);
// fflush(stdout);
scratch[tapbytes++] = (accum>>2)&0xff;
if (scratch[tapbytes-1] == 0)
{
state = TAPSEC_STATE_FINDDATA;
}
}
break;
case TAPSEC_STATE_FINDDATA:
// Look for a valid byte (start bits, valid parity)
if (validbyte(accum))
{
// printf("Data starts @ %d\n", ort_offs);
// fflush(stdout);
scratch[tapbytes++] = (accum>>2)&0xff;
data_bytes--;
bitcount=0;
state = TAPSEC_STATE_DATA;
}
break;
case TAPSEC_STATE_DATA:
bitcount = (bitcount+1)%14;
if ((bitcount==13)&&validbyte(accum)) bitcount = 0;
if (!bitcount)
{
scratch[tapbytes++] = (accum>>2)&0xff;
data_bytes--;
// printf("%d to go..\n", data_bytes);
// fflush(stdout);
// ??
if (data_bytes < 0)
{
state = TAPSEC_STATE_SEARCH;
break;
}
if (data_bytes > 0)
break;
if ((!anytapsec) && (leaderstart < 512))
leaderstart = 5;
// Got a whole standard oric tap section!
ortbuf[leaderstart++] = 0xff;
ortbuf[leaderstart++] = (tapbytes>>8)&0xff;
ortbuf[leaderstart++] = (tapbytes&0xff);
memcpy(&ortbuf[leaderstart], scratch, tapbytes);
leaderstart += tapbytes;
memmove(&ortbuf[leaderstart], &ortbuf[ort_offs], ortbuflen-ort_offs);
ortbuflen -= (ort_offs-leaderstart);
ort_offs = leaderstart;
state = TAPSEC_STATE_SEARCH;
accum = 0;
anytapsec = SDL_TRUE;
// printf("Back to scanning...\n");
// fflush(stdout);
}
break;
}
}
cyccount = 0;
}
}
return ortbuflen;
}
// This is used by the wav loader routine. It gets a sample from a wav
// file (either 8 or 16bit), and returns it as a signed value. No scaling
// is performed, so it returns -128 to 127 for 8bit wavs, and -32768 to
// 32767 for 16bit wavs.
static inline signed short getsmp(unsigned char *buf, SDL_bool is8bit)
{
return is8bit ? ((short)*buf)-128 : (short)((buf[1]<<8)|buf[0]);
}
// This converts a WAV file to Oricutron's ORT format. It should cope
// with any PCM wav file (stereo, mono, 8bit, 16bit...). It also adjusts
// any DC offset in the recording. It also calls "tapsections" to convert
// any standard oric tape format waveforms it finds into non-raw "tap"
// style sections to enable turbo loading of those parts.
SDL_bool wav_convert( struct machine *oric )
{
// Chunk pointers
unsigned char *p=oric->tapebuf, *data=NULL, *ortbuf=NULL;
unsigned int i, j, k, l, chunklen, bps=0, freq=0, smpdelta=0, datalen=0, ortlen;
signed int smaxl, sminl, smaxr, sminr, dcoffs=0, dcoffsav;
signed int *lastsmps = NULL;
signed short smp=0;
// Cycles per sample
double cps, count, pcount;
SDL_bool stereo = SDL_FALSE, fmtseen = SDL_FALSE, useright = SDL_FALSE;
// Basic validation
i = 12;
while ((!fmtseen) || (!data))
{
// Run out of data?
if (i >= (oric->tapelen-8)) return SDL_FALSE;
// Length of this chunk
chunklen = (p[i+7]<<24)|(p[i+6]<<16)|(p[i+5]<<8)|p[i+4];
// Sane length?
if ((i+chunklen+8) > oric->tapelen)
return SDL_FALSE;
// Format chunk?
if (memcmp(&p[i], "fmt ", 4) == 0)
{
// PCM?
if ((chunklen != 16) || (((p[i+9]<<8)|p[i+8])!=1))
return SDL_FALSE;
// Channels
switch ((p[i+11]<<8)|(p[i+10]))
{
case 1: stereo = SDL_FALSE; break;
case 2: stereo = SDL_TRUE; break;
default: return SDL_FALSE; break;
}
// Frequency
freq = (p[i+15]<<24)|(p[i+14]<<16)|(p[i+13]<<8)|p[i+12];
if( !freq ) return SDL_FALSE;
// Sample delta
smpdelta = (p[i+21]<<16)|p[i+20];
// Bits per sample
bps = (p[i+23]<<16)|p[i+22];
if ((bps!=8)&&(bps!=16)) return SDL_FALSE;
// Bytes per sample
bps /= 8;
fmtseen = SDL_TRUE;
}
else if (memcmp(&p[i], "data", 4) == 0)
{
data = &p[i+8];
datalen = chunklen;
}
// Skip chunk
i += chunklen+8;
}
// printf("wavsize = %d\n", datalen);
smaxl = -70000;
sminl = 70000;
smaxr = -70000;
sminr = 70000;
for (i=0; i<datalen; i+=smpdelta)
{
smp = getsmp(&data[i], bps==1);
if (smp < sminl) sminl = smp;
if (smp > smaxl) smaxl = smp;
if (stereo)
{
smp = getsmp(&data[i+bps], bps==1);
if (smp < sminr) sminr = smp;
if (smp > smaxr) smaxr = smp;
}
}
// Use the loudest channel
if ((stereo) && ((smaxr-sminr)>(smaxl-sminl)))
{
useright = SDL_TRUE;
}
else
{
useright = SDL_FALSE;
}
dcoffsav = freq / 700;
if (dcoffsav)
{
lastsmps = malloc(dcoffsav * sizeof(int));
if (lastsmps) memset(lastsmps, 0, dcoffsav * sizeof(int));
}
dcoffsav--;
// Now convert to a 1/0 squarewave
j = 0;
for (i=0; i<datalen; i+=smpdelta)
{
if (useright)
smp = getsmp(&data[i+bps], bps==1);
else
smp = getsmp(&data[i], bps==1);
if (lastsmps)
{
smaxl = smp;
sminl = smp;
for (k=0; k<dcoffsav; k++)
{
lastsmps[k] = lastsmps[k+1];
if (lastsmps[k] < sminl) sminl = lastsmps[k];
if (lastsmps[k] > smaxl) smaxl = lastsmps[k];
}
dcoffs = ((smaxl-sminl)/2)+sminl;
}
if (j >= oric->tapelen)
{
// printf("Oh dear\n");
// fflush(stdout);
break;
}
oric->tapebuf[j++] = (smp>dcoffs) ? 1 : 0;
}
// printf("ortsize = %d\n", j);
// fflush(stdout);
// Calculate cycles per sample
cps = 500000 / ((double)freq); // .ORT is 500khz
// Calculate the length of the .ORT data
ortlen = 5; // header + initial state
i = oric->tapebuf[0];
count = 0.0f;
pcount = 0.0f;
for (k=1; k<j; k++)
{
if (oric->tapebuf[k] != i)
{
i = oric->tapebuf[k];
if (((int)count) < 1)
{
// Just a spike?
if (ortlen>5) ortlen--;
count += pcount;
}
else if (((int)count) < 0xfc)
{
ortlen++;
pcount = count;
count = 0.0f;
}
else if (((int)count) < 0x100)
{
ortlen+=2;
pcount = count;
count = 0.0f;
}
else
{
ortlen+=3;
pcount = count;
count = 0.0f;
}
}
count+=cps;
}
free( lastsmps );
// Allocate a buffer for the converted data
ortbuf = malloc(ortlen);
if (!ortbuf) return SDL_FALSE;
// Write the header
memcpy(ortbuf, "ORT\0", 4);
// Write the ORT data
i = oric->tapebuf[0];
ortbuf[4] = i;
count = 0.0f;
pcount = 0.0f;
l = 5;
for (k=1; k<j; k++)
{
if (oric->tapebuf[k] != i)
{
i = oric->tapebuf[k];
if (((int)count) < 1)
{
// Just a spike. Cancel the last swap.
if (l==5)
ortbuf[4] = i;
else
l--;
count += pcount;
}
else if (((int)count) < 0xfc)
{
ortbuf[l++] = count;
pcount = count;
count = 0.0f;
}
else if (((int)count) < 0x100)
{
ortbuf[l++] = 0xfc;
ortbuf[l++] = count;
pcount = count;
count = 0.0f;
}
else
{
ortbuf[l++] = 0xfd;
ortbuf[l++] = (((int)count)>>8)&0xff;
ortbuf[l++] = ((int)count)&0xff;
pcount = count;
count = 0.0f;
}
}
count+=cps;
}
// Look for any standard oric encoded parts to convert
// to non-raw "tap" sections
ortlen = tapsections(ortbuf, ortlen, oric->tapebuf, SDL_FALSE);
ortlen = tapsections(ortbuf, ortlen, oric->tapebuf, SDL_TRUE);
// Substitute the ORT data for the original WAV data
free(oric->tapebuf);
oric->tapebuf = ortbuf;
oric->tapelen = ortlen;
return SDL_TRUE;
}
// Insert a new tape image
SDL_bool tape_load_tap( struct machine *oric, char *fname )
{
FILE *f;
// First make sure the image file exists
f = fopen( fname, "rb" );
if( !f ) return SDL_FALSE;
// Eject any old image
tape_eject( oric );