diff --git a/src/core/fds.c b/src/core/fds.c
index 37c8f8ad2..652ba68e2 100644
--- a/src/core/fds.c
+++ b/src/core/fds.c
@@ -220,6 +220,7 @@ BYTE fds_load_rom(BYTE format) {
 	fds.info.expcted_sides = fds.info.total_sides;
 	fds.info.write_protected = 0x00;
 	fds.info.cycles_8bit_delay = emu_ms_to_cpu_cycles(FDS_8BIT_MS_DELAY);
+	fds.info.cycles_insert_delay = emu_ms_to_cpu_cycles(FDS_INSERT_MS_DELAY);
 	fds.info.cycles_dummy_delay = emu_ms_to_cpu_cycles(FDS_OP_SIDE_MS_DELAY);
 
 	// converto nel mio formato immagine
@@ -367,6 +368,8 @@ BYTE fds_change_disk(uTCHAR *file) {
 	_fds_info finfo;
 	FILE *fp = NULL;
 
+	fds_free_fds_info();
+
 	memset(&finfo, 0x00, sizeof(_fds_info));
 	umemset(&path[0], 0x00, usizeof(path));
 	ustrncpy(path, file, usizeof(path) - 1);
@@ -444,10 +447,15 @@ BYTE fds_change_disk(uTCHAR *file) {
 		position = 0;
 	}
 
+	info.format = finfo.format;
+	ustrncpy(info.rom.file, path, usizeof(info.rom.file));
+
 	finfo.expcted_sides = finfo.total_sides;
 	finfo.write_protected = 0x00;
 	finfo.enabled = fds.info.enabled;
+	finfo.writings_occurred = FALSE;
 	finfo.cycles_8bit_delay = fds.info.cycles_8bit_delay;
+	finfo.cycles_insert_delay = fds.info.cycles_insert_delay;
 	finfo.cycles_dummy_delay = fds.info.cycles_dummy_delay;
 
 	// converto nel mio formato immagine
@@ -461,10 +469,6 @@ BYTE fds_change_disk(uTCHAR *file) {
 
 	finfo.frame_insert = nes[0].p.ppu.frames;
 
-	info.format = finfo.format;
-	ustrncpy(info.rom.file, path, usizeof(info.rom.file));
-
-	fds_free_fds_info();
 	memcpy(&fds.info, &finfo, sizeof(_fds_info));
 	fds_info();
 
@@ -588,7 +592,7 @@ void fds_disk_op(WORD type, BYTE side_to_insert, BYTE quiet) {
 			fds.drive.transfer_reset = 0x02;
 			fds.drive.motor_started = FALSE;
 			fds.drive.delay_8bit = 0;
-			fds.drive.delay_insert = FDS_DELAY_INSERT;
+			fds.drive.delay_insert = fds.info.cycles_insert_delay;
 			fds.auto_insert.r4032.frames = 0;
 			fds.auto_insert.r4032.checks = 0;
 			if (!quiet) {
diff --git a/src/core/fds.h b/src/core/fds.h
index cca51797d..9200b91fc 100644
--- a/src/core/fds.h
+++ b/src/core/fds.h
@@ -48,7 +48,6 @@ enum fds_misc {
 	FDS_DISK_BLOCK_MARK = 0x80,
 	FDS_AUTOINSERT_R4032_MAX_CHECKS = 7,
 	FDS_MIN_LAG_FRAMES = 20,
-	FDS_DELAY_INSERT = 90000,
 	FDS_IMAGE_SIDE_SIZE = 75500,
 	DISK_FDS_SIDE_SIZE = 65500,
 	DISK_QD_SIDE_SIZE = 65536,
@@ -64,6 +63,8 @@ enum fds_misc {
 // Aspic (1988)(Bothtec)(J) necessita di almeno 1500 ms
 // Pulsar no Hikari - Space Wars Simulation (Japan) di almeno 1600 ms
 #define FDS_OP_SIDE_MS_DELAY 1600.0f
+// Kosodate Gokko (Japan) (Unl) ha un delay di 78 ms
+#define FDS_INSERT_MS_DELAY 74.0f
 
 #define fds_auto_insert_enabled() (cfg->fds_switch_side_automatically & !fds.auto_insert.disabled & !fds.bios.first_run)
 #define fds_reset_envelope_counter(env) (fds.snd.envelope.speed << 3) * (fds.snd.env.speed + 1)
@@ -100,6 +101,7 @@ typedef struct _fds_info {
 	BYTE last_operation;
 	BYTE frame_insert;
 	uint32_t cycles_8bit_delay;
+	uint32_t cycles_insert_delay;
 	uint32_t cycles_dummy_delay;
 	_fds_info_protection protection;
 	_fds_info_side sides[20];
diff --git a/src/core/mappers/mapper_FDS.c b/src/core/mappers/mapper_FDS.c
index 73af8e1d2..b054f5683 100644
--- a/src/core/mappers/mapper_FDS.c
+++ b/src/core/mappers/mapper_FDS.c
@@ -283,7 +283,6 @@ void extcl_cpu_every_cycle_FDS(BYTE nidx) {
 
 	fds.drive.scan = FALSE;
 	fds.info.last_operation = FDS_OP_NONE;
-	fds.drive.data_available = FALSE;
 
 	if (fds.drive.motor_started) {
 		fds.drive.scan = !fds.drive.transfer_reset;
@@ -327,24 +326,27 @@ void extcl_cpu_every_cycle_FDS(BYTE nidx) {
 			fds.auto_insert.r4032.checks = 0;
 
 			if (transfer) {
-				fds.drive.data_available = 0x80;
-				fds.drive.transfer_flag = 0x02;
-
 				if (fds.drive.irq_disk_enabled) {
 					nes[nidx].c.irq.high |= FDS_DISK_IRQ;
 				}
 				if (fds.drive.io_mode) {
 					fds.drive.data_io = data;
-					fds.info.last_operation = FDS_OP_READ;
+					if (!fds.drive.data_available) {
+						fds.info.last_operation = FDS_OP_READ;
+					}
 				} else {
 					fds.side.info->data[fds.drive.disk_position] = data;
 					fds.info.writings_occurred = TRUE;
-					fds.info.last_operation = FDS_OP_WRITE;
+					if (!fds.drive.data_available) {
+						fds.info.last_operation = FDS_OP_WRITE;
+					}
 				}
+				fds.drive.data_available = 0x80;
+				fds.drive.transfer_flag = 0x02;
 			}
 		}
 		if (++fds.drive.disk_position >= fds.info.sides[fds.drive.side_inserted].size) {
-			fds.drive.delay_insert = FDS_DELAY_INSERT;
+			fds.drive.delay_insert = fds.info.cycles_insert_delay;
 			fds.drive.end_of_head = 0x40;
 			// Bishoujo Alien Battle (Japan) (Unl).fds non esegue la routine a 0xE188
 			fds.auto_insert.in_game = TRUE;