From: Toni Wilen <twilen@winuae.net>
Date: Sat, 13 Jan 2024 14:58:30 +0000 (+0200)
Subject: Floppy emulation updates to support DraCo polled flux change timed Amiga disk reads.
X-Git-Tag: 5200~68
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=ff3f284895ec2b7fd6ce2bd928a5a86579a65c8f;p=francis%2Fwinuae.git

Floppy emulation updates to support DraCo polled flux change timed Amiga disk reads.
---

diff --git a/disk.cpp b/disk.cpp
index 20e05314..7c4f96ee 100644
--- a/disk.cpp
+++ b/disk.cpp
@@ -928,7 +928,7 @@ static void update_drive_gui(int num, bool force)
 	gui_led (num + LED_DF0, (gid->drive_motor ? 1 : 0) | (gid->drive_writing ? 2 : 0), -1);
 }
 
-static void drive_fill_bigbuf (drive * drv,int);
+static void drive_fill_bigbuf(drive *drv, int, int);
 
 void DISK_get_path_text(struct uae_prefs *p, int n, TCHAR *text)
 {
@@ -1440,7 +1440,7 @@ static int drive_insert (drive *drv, struct uae_prefs *p, int dnum, const TCHAR
 		drive_settype_id(drv); /* Set DD or HD drive */
 		update_drive_gui(drv->drvnum, false);
 		update_disk_statusline(drv->drvnum);
-		drive_fill_bigbuf(drv, fake ? -1 : 1);
+		drive_fill_bigbuf(drv, side, fake ? -1 : 1);
 
 		return 1;
 #endif
@@ -1737,7 +1737,7 @@ static int drive_insert (drive *drv, struct uae_prefs *p, int dnum, const TCHAR
 	}
 	openwritefile(p, drv, 0);
 	drive_settype_id(drv); /* Set DD or HD drive */
-	drive_fill_bigbuf(drv, 1);
+	drive_fill_bigbuf(drv, side, 1);
 	drv->mfmpos = uaerand();
 	drv->mfmpos |= uaerand() << 16;
 	drv->mfmpos &= 0xffffff;
@@ -2077,10 +2077,10 @@ static uae_u16 *mfmcoder (uae_u8 *src, uae_u16 *dest, int len)
 	return dest;
 }
 
-static void decode_pcdos (drive *drv)
+static void decode_pcdos (drive *drv, int tside)
 {
 	int i, len;
-	int tr = drv->cyl * 2 + side;
+	int tr = drv->cyl * 2 + tside;
 	uae_u16 *dstmfmbuf, *mfm2;
 	uae_u8 secbuf[1000];
 	uae_u16 crc16;
@@ -2143,10 +2143,10 @@ static void decode_pcdos (drive *drv)
 		write_log (_T("pcdos read track %d\n"), tr);
 }
 
-static void decode_amigados (drive *drv)
+static void decode_amigados(drive *drv, int tside)
 {
 	/* Normal AmigaDOS format track */
-	int tr = drv->cyl * 2 + side;
+	int tr = drv->cyl * 2 + tside;
 	int sec;
 	int dstmfmoffset = 0;
 	uae_u16 *dstmfmbuf = drv->bigmfmbuf;
@@ -2265,9 +2265,9 @@ static void decode_amigados (drive *drv)
 *
 */
 
-static void decode_diskspare (drive *drv)
+static void decode_diskspare(drive *drv, int tside)
 {
-	int tr = drv->cyl * 2 + side;
+	int tr = drv->cyl * 2 + tside;
 	int sec;
 	int dstmfmoffset = 0;
 	int size = 512 + 8;
@@ -2341,9 +2341,9 @@ static void decode_diskspare (drive *drv)
 		write_log (_T("diskspare read track %d\n"), tr);
 }
 
-static void drive_fill_bigbuf (drive * drv, int force)
+static void drive_fill_bigbuf(drive *drv, int tside, int force)
 {
-	int tr = drv->cyl * 2 + side;
+	int tr = drv->cyl * 2 + tside;
 	trackid *ti = drv->trackdata + tr;
 	bool retrytrack;
 	int rev = -1;
@@ -2362,17 +2362,17 @@ static void drive_fill_bigbuf (drive * drv, int force)
 		return;
 	}
 
-	if (!force && drv->buffered_cyl == drv->cyl && drv->buffered_side == side)
+	if (!force && drv->buffered_cyl == drv->cyl && drv->buffered_side == tside)
 		return;
 	drv->indexoffset = 0;
 	drv->multi_revolution = 0;
 	drv->tracktiming[0] = 0;
 	drv->skipoffset = -1;
 	drv->revolutions = 1;
-	retrytrack = drv->lastdataacesstrack == drv->cyl * 2 + side;
+	retrytrack = drv->lastdataacesstrack == drv->cyl * 2 + tside;
 	if (!dskdmaen && !retrytrack)
 		drv->track_access_done = false;
-	//write_log (_T("%d:%d %d\n"), drv->cyl, side, retrytrack);
+	//write_log (_T("%d:%d %d\n"), drv->cyl, tside, retrytrack);
 
 	if (drv->writediskfile && drv->writetrackdata[tr].bitlen > 0) {
 		int i;
@@ -2392,7 +2392,7 @@ static void drive_fill_bigbuf (drive * drv, int force)
 		if (drv->bridge) {
 			drv->multi_revolution = 1;
 			drv->skipoffset = -1;
-			drv->bridge->setSurface(side); // force the correct disk side to be selected
+			drv->bridge->setSurface(tside); // force the correct disk side to be selected
 			drv->tracklen = drv->bridge->maxMFMBitPosition();
 			drv->tracktiming[0] = drv->bridge->getMFMSpeed(drv->mfmpos % drv->tracklen);
 			if (force < 0) {
@@ -2404,7 +2404,7 @@ static void drive_fill_bigbuf (drive * drv, int force)
 #ifdef CATWEASEL
 		drv->tracklen = 0;
 		if (!catweasel_disk_changed (drv->catweasel)) {
-			drv->tracklen = catweasel_fillmfm (drv->catweasel, drv->bigmfmbuf, side, drv->ddhd, 0);
+			drv->tracklen = catweasel_fillmfm (drv->catweasel, drv->bigmfmbuf, tside, drv->ddhd, 0);
 		}
 		drv->buffered_cyl = -1;
 		if (!drv->tracklen) {
@@ -2432,15 +2432,15 @@ static void drive_fill_bigbuf (drive * drv, int force)
 
 	} else if (ti->type == TRACK_PCDOS) {
 
-		decode_pcdos(drv);
+		decode_pcdos(drv, tside);
 
 	} else if (ti->type == TRACK_AMIGADOS) {
 
-		decode_amigados(drv);
+		decode_amigados(drv, tside);
 
 	} else if (ti->type == TRACK_DISKSPARE) {
 
-		decode_diskspare(drv);
+		decode_diskspare(drv, tside);
 
 	} else if (ti->type == TRACK_NONE) {
 
@@ -2460,7 +2460,7 @@ static void drive_fill_bigbuf (drive * drv, int force)
 		if (disk_debug_logging > 2)
 			write_log (_T("rawtrack %d image offset=%x\n"), tr, ti->offs);
 	}
-	drv->buffered_side = side;
+	drv->buffered_side = tside;
 	drv->buffered_cyl = drv->cyl;
 	if (drv->tracklen == 0) {
 		drv->tracklen = FLOPPY_WRITE_LEN * drv->ddhd * 2 * 8;
@@ -2885,7 +2885,7 @@ static bool convert_adf_to_ext2 (drive *drv, int mode)
 #ifdef RETROPLATFORM
 	rp_disk_image_change(drv->drvnum, name, false);
 #endif
-	drive_fill_bigbuf(drv, 1);
+	drive_fill_bigbuf(drv, side, 1);
 
 	return true;
 }
@@ -4493,6 +4493,36 @@ static void disk_dma_debugmsg (void)
 		dsklength, dsklength, (adkcon & 0x400) ? dsksync : 0xffff, dskpt, adkcon, intreq, M68K_GETPC);
 }
 
+// fake raw read for draco
+uae_u16 DSKBYTR_fake(int num)
+{
+	drive *drv = &floppy[num];
+	uae_u16 ret;
+	uae_u16 ac = adkcon;
+	
+	adkcon |= 0x100;
+	int mfmpos = drv->mfmpos;
+	bool isempty = drive_empty(drv);
+	bool isunformatted = unformatted(drv);
+	int inc = 1;
+	int fword = 0;
+	for (int i = 0; i < 8; i++) {
+		fword <<= 1;
+		if (!isempty) {
+			if (isunformatted)
+				fword |= (uaerand() & 0x1000) ? 1 : 0;
+			else
+				fword |= getonebit(drv, drv->bigmfmbuf, mfmpos, &inc);
+		}
+		mfmpos += inc;
+		mfmpos %= drv->tracklen;
+	}
+	drv->mfmpos = mfmpos;
+	ret = 0x8000 | (fword & 0xff);
+	adkcon = ac;
+	return ret;
+}
+
 /* this is very unoptimized. DSKBYTR is used very rarely, so it should not matter. */
 
 uae_u16 DSKBYTR(int hpos)
@@ -4603,13 +4633,13 @@ static void DISK_start(void)
 #ifdef CATWEASEL
 			if (drv->catweasel) {
 				word = 0;
-				drive_fill_bigbuf (drv, 1);
+				drive_fill_bigbuf (drv, side, 1);
 			}
 #endif
 #ifdef FLOPPYBRIDGE
 			if (drv->bridge && dskdmaen != DSKDMA_WRITE) {
 				word = 0;
-				drive_fill_bigbuf(drv, 1);
+				drive_fill_bigbuf(drv, side, 1);
 			}
 #endif
 		}
@@ -4728,11 +4758,11 @@ void DISK_update (int tohpos)
 			continue;
 		}
 		if (drv->diskfile) {
-			drive_fill_bigbuf(drv, 0);
+			drive_fill_bigbuf(drv, side, 0);
 		}
 #ifdef FLOPPYBRIDGE
 		if (drv->bridge) {
-			drive_fill_bigbuf(drv, 0);
+			drive_fill_bigbuf(drv, side, 0);
 		}
 #endif
 		drv->mfmpos %= drv->tracklen;
@@ -4962,7 +4992,7 @@ static void DSKLEN_2(uae_u16 v, int hpos)
 				continue;
 
 			pos = drv->mfmpos & ~15;
-			drive_fill_bigbuf (drv, 0);
+			drive_fill_bigbuf (drv, side, 0);
 
 			if (dskdmaen == DSKDMA_READ) { /* TURBO read */
 
@@ -5443,7 +5473,7 @@ static void load_track (int num, int cyl, int dside, int *sectable)
 	drv->cyl = cyl;
 	side = dside;
 	drv->buffered_cyl = -1;
-	drive_fill_bigbuf (drv, -1);
+	drive_fill_bigbuf (drv, side, -1);
 	decode_buffer (drv, drv->bigmfmbuf, drv->cyl, 11, drv->ddhd, drv->filetype, &drvsec, sectable, 1);
 	drv->cyl = oldcyl;
 	side = oldside;
@@ -6244,6 +6274,12 @@ void disk_reserved_setinfo(int num, int cyl, int head, int motor)
 		drv->cyl = cyl;
 		drv->state = motor != 0;
 		update_drive_gui(i, false);
+		drive_fill_bigbuf(drv, head, 0);
+		// for some reason draco does not like it if data read starts from beginning of gap
+		drv->mfmpos = 8 * 16;
+		while ((drv->bigmfmbuf[drv->mfmpos / 16] == 0xaaaa || drv->bigmfmbuf[drv->mfmpos / 16] == 0x5555) && drv->mfmpos < 2048 && drv->mfmpos < drv->tracklen / 4) {
+			drv->mfmpos += 16;
+		}
 	}
 }
 
@@ -6262,7 +6298,7 @@ bool disk_reserved_getinfo(int num, struct floppy_reserved *fr)
 			if (z) {
 				bool ok = false;
 				drv->num_secs = 21; // max possible
-				drive_fill_bigbuf(drv, true);
+				drive_fill_bigbuf(drv, side, true);
 				int secs = drive_write_pcdos(drv, z, 1);
 				if (secs >= 8) {
 					ok = true;
@@ -6270,7 +6306,7 @@ bool disk_reserved_getinfo(int num, struct floppy_reserved *fr)
 					for (int i = 0; i < drv->num_tracks; i++) {
 						drv->cyl = i / 2;
 						side = i & 1;
-						drive_fill_bigbuf(drv, true);
+						drive_fill_bigbuf(drv, side, true);
 						drive_write_pcdos(drv, z, 0);
 					}
 				}
diff --git a/include/disk.h b/include/disk.h
index 7da217fd..bfffae00 100644
--- a/include/disk.h
+++ b/include/disk.h
@@ -109,6 +109,7 @@ extern uae_u16 DSKDATR (int);
 extern uae_u16 disk_dmal (void);
 extern uaecptr disk_getpt (void);
 extern int disk_fifostatus (void);
+extern uae_u16 DSKBYTR_fake(int);
 
 extern int disk_debug_logging;
 extern int disk_debug_mode;
diff --git a/include/x86.h b/include/x86.h
index d153e228..62c3d18d 100644
--- a/include/x86.h
+++ b/include/x86.h
@@ -23,5 +23,6 @@ uae_u8 x86_infloppy(int portnum);
 void x86_outfloppy(int portnum, uae_u8 v);
 void x86_initfloppy(X86_INTERRUPT_CALLBACK);
 void x86_floppy_run(void);
+uae_u16 floppy_get_raw_data(void);
 
 #endif /* UAE_X86_H */
diff --git a/x86.cpp b/x86.cpp
index dcbf3dc8..92d94598 100644
--- a/x86.cpp
+++ b/x86.cpp
@@ -554,6 +554,7 @@ struct pc_floppy
 	int cyl;
 	uae_u8 sector;
 	uae_u8 head;
+	bool disk_changed;
 };
 
 static struct pc_floppy floppy_pc[4];
@@ -625,13 +626,21 @@ static void do_floppy_irq(void)
 
 static void do_floppy_seek(int num, int error)
 {
-	struct pc_floppy *pcf = &floppy_pc[floppy_num];
+	struct pc_floppy *pcf = &floppy_pc[num];
 
 	disk_reserved_reset_disk_change(num);
 	if (!error) {
 		struct floppy_reserved fr = { 0 };
-		bool valid_floppy = disk_reserved_getinfo(floppy_num, &fr);
+		bool valid_floppy = disk_reserved_getinfo(num, &fr);
 		if (floppy_seekcyl[num] != pcf->phys_cyl) {
+
+			if (!valid_floppy || !fr.img) {
+				error = 1;
+				goto done;
+			}
+
+			pcf->disk_changed = false;
+
 			if (floppy_seekcyl[num] > pcf->phys_cyl)
 				pcf->phys_cyl++;
 			else if (pcf->phys_cyl > 0)
@@ -642,14 +651,14 @@ static void do_floppy_seek(int num, int error)
 				driveclick_click(fr.num, pcf->phys_cyl);
 #endif
 #if FLOPPY_DEBUG
-			write_log(_T("Floppy%d seeking.. %d\n"), floppy_num, pcf->phys_cyl);
+			write_log(_T("Floppy%d seeking.. %d\n"), num, pcf->phys_cyl);
 #endif
 			if (pcf->phys_cyl - pcf->seek_offset <= 0) {
 				pcf->phys_cyl = 0;
 				if (pcf->seek_offset) {
 					floppy_seekcyl[num] = 0;
 #if FLOPPY_DEBUG
-					write_log(_T("Floppy%d early track zero\n"), floppy_num);
+					write_log(_T("Floppy%d early track zero\n"), num);
 #endif
 					pcf->seek_offset = 0;
 				}
@@ -661,7 +670,7 @@ static void do_floppy_seek(int num, int error)
 				pcf->cyl = pcf->phys_cyl;
 
 			floppy_seeking[num] = PC_SEEK_DELAY;
-			disk_reserved_setinfo(floppy_num, pcf->cyl, pcf->head, 1);
+			disk_reserved_setinfo(num, pcf->cyl, pcf->head, 1);
 			return;
 		}
 
@@ -682,7 +691,7 @@ static void do_floppy_seek(int num, int error)
 
 done:
 #if FLOPPY_DEBUG
-	write_log(_T("Floppy%d seek done err=%d. pcyl=%d cyl=%d h=%d\n"), floppy_num, error, pcf->phys_cyl,pcf->cyl, pcf->head);
+	write_log(_T("Floppy%d seek done err=%d. pcyl=%d cyl=%d h=%d\n"), num, error, pcf->phys_cyl,pcf->cyl, pcf->head);
 #endif
 	floppy_status[0] = 0;
 	floppy_status[0] |= 0x20; // seek end
@@ -716,6 +725,21 @@ static int floppy_selected(void)
 	return -1;
 }
 
+static void floppy_clear_irq(void)
+{
+	if (floppy_irq) {
+		x86_clearirq(6);
+		floppy_irq = false;
+	}
+}
+
+static bool floppy_valid_format(struct floppy_reserved *fr)
+{
+	if (fr->secs == 11 || fr->secs == 22)
+		return false;
+	return true;
+}
+
 static bool floppy_valid_rate(struct floppy_reserved *fr)
 {
 	struct x86_bridge *xb = bridges[0];
@@ -763,8 +787,7 @@ static void floppy_do_cmd(struct x86_bridge *xb)
 			// 0xc0 status after reset.
 			floppy_status[0] = 0xc0;
 		}
-		x86_clearirq(6);
-		floppy_irq = false;
+		floppy_clear_irq();
 		floppy_result[0] = floppy_status[0];
 		floppy_result[1] = pcf->phys_cyl;
 		floppy_status[0] = 0;
@@ -833,16 +856,20 @@ static void floppy_do_cmd(struct x86_bridge *xb)
 					while (!end && !fr.wrprot) {
 						int len = 128 << floppy_cmd[5];
 						uae_u8 buf[512] = { 0 };
-						for (int i = 0; i < 512 && i < len; i++) {
-							int v = dma_channel_read(2);
-							if (v < 0) {
-								end = -1;
-								break;
-							}
-							buf[i] = v;
-							if (v >= 0x10000) {
-								end = 1;
-								break;
+						if (floppy_specify_pio) {
+							end = -1;
+						} else {
+							for (int i = 0; i < 512 && i < len; i++) {
+								int v = dma_channel_read(2);
+								if (v < 0) {
+									end = -1;
+									break;
+								}
+								buf[i] = v;
+								if (v >= 0x10000) {
+									end = 1;
+									break;
+								}
 							}
 						}
 #if FLOPPY_DEBUG
@@ -907,7 +934,7 @@ static void floppy_do_cmd(struct x86_bridge *xb)
 			int cyl = pcf->cyl;
 			bool nodata = false;
 			if (valid_floppy) {
-				if (!floppy_valid_rate(&fr)) {
+				if (!floppy_valid_rate(&fr) || !floppy_valid_format(&fr)) {
 					nodata = true;
 				} else if (pcf->head && fr.heads == 1) {
 					nodata = true;
@@ -991,7 +1018,7 @@ static void floppy_do_cmd(struct x86_bridge *xb)
 #if FLOPPY_DEBUG
 		write_log(_T("Floppy read ID\n"));
 #endif
-		if (!valid_floppy || !fr.img || !floppy_valid_rate(&fr) || (pcf->head && fr.heads == 1)) {
+		if (!valid_floppy || !fr.img || !floppy_valid_rate(&fr) || (pcf->head && fr.heads == 1) || !floppy_valid_format(&fr)) {
 			floppy_status[0] |= 0x40; // abnormal termination
 			floppy_status[1] |= 0x04; // no data
 		}
@@ -1107,6 +1134,10 @@ static int draco_force_irq;
 
 static void outfloppy(struct x86_bridge *xb, int portnum, uae_u8 v)
 {
+#if FLOPPY_IO_DEBUG
+	write_log(_T("out floppy port %04x %02x\n"), portnum, v);
+#endif
+
 	switch (portnum)
 	{
 		case 0x3f2: // dpc
@@ -1129,12 +1160,12 @@ static void outfloppy(struct x86_bridge *xb, int portnum, uae_u8 v)
 		}
 #endif
 		floppy_dpc = v;
-		if (xb->type < 0 && 1) {
+		if (xb->type < 0) {
 			floppy_dpc |= 8;
 		}
 		floppy_num = v & 3;
 		for (int i = 0; i < 2; i++) {
-			disk_reserved_setinfo(0, floppy_pc[i].cyl, floppy_pc[i].head, floppy_selected() == i);
+			disk_reserved_setinfo(i, floppy_pc[i].cyl, floppy_pc[i].head, floppy_selected() == i);
 		}
 		break;
 		case 0x3f5: // data reg
@@ -1210,9 +1241,6 @@ static void outfloppy(struct x86_bridge *xb, int portnum, uae_u8 v)
 		write_log(_T("Unknown FDC %04x write %02x\n"), portnum, v);
 		break;
 	}
-#if FLOPPY_IO_DEBUG
-	write_log(_T("out floppy port %04x %02x\n"), portnum, v);
-#endif
 }
 
 static uae_u8 infloppy(struct x86_bridge *xb, int portnum)
@@ -1265,6 +1293,8 @@ static uae_u8 infloppy(struct x86_bridge *xb, int portnum)
 			v = floppy_pio_buffer[floppy_pio_cnt++];
 			if (floppy_pio_cnt >= floppy_pio_len) {
 				floppy_pio_len = 0;
+				floppy_clear_irq();
+				floppy_delay_hsync = 50;
 			}
 		} else if (floppy_cmd_len && floppy_dir) {
 			int idx = (-floppy_idx) - 1;
@@ -1276,23 +1306,23 @@ static uae_u8 infloppy(struct x86_bridge *xb, int portnum)
 					floppy_cmd_len = 0;
 					floppy_dir = 0;
 					floppy_idx = 0;
+					floppy_clear_irq();
 				}
 			}
 		}
 		break;
 		case 0x3f7: // digital input register
-		if (xb->type >= TYPE_2286) {
+		if (xb->type >= TYPE_2286 || xb->type < 0) {
+			struct pc_floppy *pcf = &floppy_pc[floppy_num];
 			struct floppy_reserved fr = { 0 };
 			bool valid_floppy = disk_reserved_getinfo(floppy_num, &fr);
 			v = 0x00;
-			if (valid_floppy && fr.disk_changed)
-				v = 0x80;
-		} else if (xb->type < 0) {
-			struct floppy_reserved fr = { 0 };
-			bool valid_floppy = disk_reserved_getinfo(floppy_num, &fr);
-			v = 0x00;
-			if (fr.disk_changed)
+			if (valid_floppy && fr.disk_changed && (floppy_dpc >> 4) & (1 << floppy_num)) {
+				pcf->disk_changed = true;
+			}
+			if (pcf->disk_changed) {
 				v = 0x80;
+			}
 		}
 		break;
 		default:
@@ -1305,6 +1335,16 @@ static uae_u8 infloppy(struct x86_bridge *xb, int portnum)
 	return v;
 }
 
+uae_u16 floppy_get_raw_data(void)
+{
+	struct floppy_reserved fr = { 0 };
+	bool valid_floppy = disk_reserved_getinfo(floppy_num, &fr);
+	if (valid_floppy) {
+		return DSKBYTR_fake(fr.num);
+	}
+	return 0x8000;
+}
+
 static void set_cpu_turbo(struct x86_bridge *xb)
 {
 	cpu_multiplier = (int)currprefs.x86_speed_throttle;