From 04193fb1996363f2c18b2fe5e3acc1ea684a63dc Mon Sep 17 00:00:00 2001
From: OBattler <oubattler@gmail.com>
Date: Mon, 23 Mar 2020 09:02:32 +0100
Subject: [PATCH] Floppy changes.

---
 src/floppy/fdc.c     | 47 +++++++++++++++++++++++++-------------------
 src/floppy/fdc.h     |  2 +-
 src/floppy/fdd_86f.c |  2 +-
 3 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/src/floppy/fdc.c b/src/floppy/fdc.c
index 81274199c..d4eebc796 100644
--- a/src/floppy/fdc.c
+++ b/src/floppy/fdc.c
@@ -702,10 +702,6 @@ fdc_write(uint16_t addr, uint8_t val, void *priv)
 				fdc->stat = 0x00;
 				fdc->pnum = fdc->ptot = 0;
 			}
-                        if (val&4) {
-				fdc->stat = 0x80;
-				fdc->pnum = fdc->ptot = 0;
-                        }
 			if ((val&4) && !(fdc->dor&4)) {
 				timer_set_delay_u64(&fdc->timer, 8 * TIMER_USEC);
 				fdc->interrupt = -1;
@@ -775,7 +771,16 @@ fdc_write(uint16_t addr, uint8_t val, void *priv)
 			fdc->stat |= 0x10;
 			fdc_log("Starting FDC command %02X\n",fdc->command);
 
-			switch (fdc->command & 0x1f) {
+			if (((fdc->command & 0x1f) == 0x02) || ((fdc->command & 0x1f) == 0x05) ||
+			    ((fdc->command & 0x1f) == 0x06) || ((fdc->command & 0x1f) == 0x0a) ||
+			    ((fdc->command & 0x1f) == 0x0c) || ((fdc->command & 0x1f) == 0x0d) ||
+			    ((fdc->command & 0x1f) == 0x11) || ((fdc->command & 0x1f) == 0x16) ||
+			    ((fdc->command & 0x1f) == 0x19) || ((fdc->command & 0x1f) == 0x1d))
+				fdc->processed_cmd = fdc->command & 0x1f;
+			else
+				fdc->processed_cmd = fdc->command;
+
+			switch (fdc->processed_cmd) {
 				case 0x01: /*Mode*/
 					if (fdc->flags & FDC_FLAG_NSC) {
 						fdc->pnum = 0;
@@ -921,7 +926,7 @@ fdc_write(uint16_t addr, uint8_t val, void *priv)
 			}
                         if (fdc->pnum == fdc->ptot) {
 				fdc_log("Got all params %02X\n", fdc->command);
-				fdc->interrupt = fdc->command & 0x1F;
+				fdc->interrupt = fdc->processed_cmd;
 				fdc->reset_stat = 0;
 				/* Disable timer if enabled. */
 				timer_disable(&fdc->timer);
@@ -950,7 +955,7 @@ fdc_write(uint16_t addr, uint8_t val, void *priv)
 						break;
 				}
 				/* Process the firt phase of the command. */
-				switch (fdc->interrupt & 0x1F) {
+				switch (fdc->processed_cmd) {
 					case 0x02:	/* Read a track */
 						fdc_io_command_phase1(fdc, 0);
 						fdc->read_track_sector.id.c = fdc->params[1];
@@ -1072,7 +1077,8 @@ fdc_write(uint16_t addr, uint8_t val, void *priv)
 						fdc->stat =  (1 << fdc->drive);
 						if (!(fdc->flags & FDC_FLAG_PCJR))
 							fdc->stat |= 0x80;
-						fdc->head = (fdc->params[0] & 4) ? 1 : 0;
+						/* fdc->head = (fdc->params[0] & 4) ? 1 : 0; */
+						fdc->head = 0;	/* TODO: See if this is correct. */
 						fdc->st0 = fdc->params[0] & 0x03;
 						fdc->st0 |= (fdc->params[0] & 4);
 						fdc->st0 |= 0x80;
@@ -1210,21 +1216,22 @@ fdc_read(uint16_t addr, void *priv)
 			}
 		} else {
 			if (is486 || !fdc->enable_3f1)
-				return 0xff;
+				ret = 0xff;
+			else {
+				ret = 0x70;
 
-			ret = 0x70;
+				drive = real_drive(fdc, fdc->dor & 3);
 
-			drive = real_drive(fdc, fdc->dor & 3);
+				if (drive)
+					ret &= ~0x40;
+				else
+					ret &= ~0x20;
 
-			if (drive)
-				ret &= ~0x40;
-			else
-				ret &= ~0x20;
-
-			if (fdc->dor & 0x10)
-				ret |= 1;
-			if (fdc->dor & 0x20)
-				ret |= 2;
+				if (fdc->dor & 0x10)
+					ret |= 1;
+				if (fdc->dor & 0x20)
+					ret |= 2;
+			}
 		}
 		break;
 	case 2:
diff --git a/src/floppy/fdc.h b/src/floppy/fdc.h
index 786d1bfe5..4fae14c62 100644
--- a/src/floppy/fdc.h
+++ b/src/floppy/fdc.h
@@ -36,7 +36,7 @@
 
 
 typedef struct {
-    uint8_t	dor, stat, command, dat, st0, swap;
+    uint8_t	dor, stat, command, processed_cmd, dat, st0, swap;
     uint8_t	swwp, disable_write;
     uint8_t	params[256], res[256];
     uint8_t	specify[256], format_dat[256];
diff --git a/src/floppy/fdd_86f.c b/src/floppy/fdd_86f.c
index d55f86734..8eb4d0f42 100644
--- a/src/floppy/fdd_86f.c
+++ b/src/floppy/fdd_86f.c
@@ -826,7 +826,7 @@ d86f_byteperiod(int drive)
 int
 d86f_is_mfm(int drive)
 {
-    return (d86f_track_flags(drive) & 8) ? 1 : 0;
+    return ((d86f_track_flags(drive) & 0x18) == 0x08) ? 1 : 0;
 }