diff --git a/Source/HBIOS/ch376-native/base-drv/enumerate.c.s b/Source/HBIOS/ch376-native/base-drv/enumerate.c.s
index 4a86dcf6..68f236e6 100644
--- a/Source/HBIOS/ch376-native/base-drv/enumerate.c.s
+++ b/Source/HBIOS/ch376-native/base-drv/enumerate.c.s
@@ -923,65 +923,7 @@ l_read_all_configs_00112:
 	ld	sp, ix
 	pop	ix
 	ret
-;source-doc/base-drv/enumerate.c:189: static uint8_t count_storage_devs(enumeration_state *state) {
-; ---------------------------------
-; Function count_storage_devs
-; ---------------------------------
-_count_storage_devs:
-	push	ix
-	ld	ix,0
-	add	ix,sp
-;source-doc/base-drv/enumerate.c:192: do {
-	ld	c,0x01
-l_count_storage_devs_00106:
-;source-doc/base-drv/enumerate.c:193: device_config_storage *const storage_device = (device_config_storage *)get_usb_device_config(index);
-	push	bc
-	ld	a, c
-	call	_get_usb_device_config
-	pop	bc
-;source-doc/base-drv/enumerate.c:195: if (storage_device == NULL)
-	ld	a, d
-	or	e
-	jr	Z,l_count_storage_devs_00108
-;source-doc/base-drv/enumerate.c:198: const usb_device_type t = storage_device->type;
-	ld	l, e
-	ld	h, d
-	ld	a, (hl)
-	and	0x0f
-;source-doc/base-drv/enumerate.c:200: if (t == USB_IS_FLOPPY || t == USB_IS_MASS_STORAGE)
-	cp	0x01
-	jr	Z,l_count_storage_devs_00103
-	sub	0x02
-	jr	NZ,l_count_storage_devs_00107
-l_count_storage_devs_00103:
-;source-doc/base-drv/enumerate.c:201: storage_device->drive_index = state->storage_count++;
-	ld	hl,0x0010
-	add	hl, de
-	ex	de, hl
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	inc	hl
-	ld	a, (hl)
-	ld	b, a
-	inc	b
-	ld	(hl), b
-	ld	(de), a
-l_count_storage_devs_00107:
-;source-doc/base-drv/enumerate.c:203: } while (++index != MAX_NUMBER_OF_DEVICES + 1);
-	inc	c
-	ld	a, c
-	sub	0x07
-	jr	NZ,l_count_storage_devs_00106
-l_count_storage_devs_00108:
-;source-doc/base-drv/enumerate.c:205: return state->storage_count;
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	inc	hl
-	ld	l, (hl)
-;source-doc/base-drv/enumerate.c:206: }
-	pop	ix
-	ret
-;source-doc/base-drv/enumerate.c:208: usb_error enumerate_all_devices(void) {
+;source-doc/base-drv/enumerate.c:189: usb_error enumerate_all_devices(void) {
 ; ---------------------------------
 ; Function enumerate_all_devices
 ; ---------------------------------
@@ -990,35 +932,28 @@ _enumerate_all_devices:
 	ld	ix,0
 	add	ix,sp
 	push	af
-;source-doc/base-drv/enumerate.c:209: _usb_state *const work_area = get_usb_work_area();
-;source-doc/base-drv/enumerate.c:211: memset(&state, 0, sizeof(enumeration_state));
+;source-doc/base-drv/enumerate.c:190: _usb_state *const work_area = get_usb_work_area();
+;source-doc/base-drv/enumerate.c:192: memset(&state, 0, sizeof(enumeration_state));
 	ld	hl,0
 	add	hl, sp
+	ld	e,l
+	ld	d,h
 	xor	a
 	ld	(hl), a
 	inc	hl
 	ld	(hl), a
-;source-doc/base-drv/enumerate.c:213: usb_error result = read_all_configs(&state);
-	ld	hl,0
-	add	hl, sp
-	push	hl
-	push	hl
+;source-doc/base-drv/enumerate.c:194: usb_error result = read_all_configs(&state);
+	push	de
+	push	de
 	call	_read_all_configs
 	pop	af
-	ld	c, l
-	pop	hl
-;source-doc/base-drv/enumerate.c:215: count_storage_devs(&state);
-	push	bc
-	push	hl
-	call	_count_storage_devs
-	pop	af
-	pop	bc
-;source-doc/base-drv/enumerate.c:217: work_area->count_of_detected_usb_devices = state.next_device_address;
-	ld	a,(ix-2)
-	ld	((_x + 1)),a
-;source-doc/base-drv/enumerate.c:220: return result;
-	ld	l, c
-;source-doc/base-drv/enumerate.c:221: }
+	pop	de
+;source-doc/base-drv/enumerate.c:196: work_area->count_of_detected_usb_devices = state.next_device_address;
+	ld	bc,_x + 1
+	ld	a, (de)
+	ld	(bc), a
+;source-doc/base-drv/enumerate.c:199: return result;
+;source-doc/base-drv/enumerate.c:200: }
 	ld	sp, ix
 	pop	ix
 	ret
diff --git a/Source/HBIOS/ch376-native/base-drv/hbios-driver-storage.c.s b/Source/HBIOS/ch376-native/base-drv/hbios-driver-storage.c.s
index 578b9289..dfc56fb0 100644
--- a/Source/HBIOS/ch376-native/base-drv/hbios-driver-storage.c.s
+++ b/Source/HBIOS/ch376-native/base-drv/hbios-driver-storage.c.s
@@ -34,7 +34,7 @@ _USB_MODULE_LEDS	.EQU	0xff8a
 ; .area _INITIALIZED removed by z88dk
 	
 _hbios_usb_storage_devices:
-	DEFS 24
+	DEFS 12
 	
 #ENDIF
 	
@@ -55,7 +55,7 @@ _hbios_usb_storage_devices:
 ; Function find_storage_dev
 ; ---------------------------------
 _find_storage_dev:
-;source-doc/base-drv/hbios-driver-storage.c:6: for(uint8_t i = 0; i < MAX_NUMBER_OF_DEVICES; i++)
+;source-doc/base-drv/hbios-driver-storage.c:6: for (uint8_t i = 0; i < MAX_NUMBER_OF_DEVICES; i++)
 	ld	c,0x00
 	ld	de,_hbios_usb_storage_devices+0
 	ld	b,c
@@ -63,22 +63,19 @@ l_find_storage_dev_00105:
 	ld	a, b
 	sub	0x06
 	jr	NC,l_find_storage_dev_00103
-;source-doc/base-drv/hbios-driver-storage.c:7: if (hbios_usb_storage_devices[i].storage_device == NULL)
+;source-doc/base-drv/hbios-driver-storage.c:7: if (hbios_usb_storage_devices[i].drive_index == 0)
 	ld	l, b
 	ld	h,0x00
 	add	hl, hl
-	add	hl, hl
 	add	hl, de
 	ld	a, (hl)
-	inc	hl
-	ld	l, (hl)
-	or	l
+	or	a
 	jr	NZ,l_find_storage_dev_00106
 ;source-doc/base-drv/hbios-driver-storage.c:8: return i;
 	ld	l, c
 	jr	l_find_storage_dev_00107
 l_find_storage_dev_00106:
-;source-doc/base-drv/hbios-driver-storage.c:6: for(uint8_t i = 0; i < MAX_NUMBER_OF_DEVICES; i++)
+;source-doc/base-drv/hbios-driver-storage.c:6: for (uint8_t i = 0; i < MAX_NUMBER_OF_DEVICES; i++)
 	inc	b
 	ld	c, b
 	jr	l_find_storage_dev_00105
@@ -89,7 +86,6 @@ l_find_storage_dev_00107:
 ;source-doc/base-drv/hbios-driver-storage.c:11: }
 	ret
 _hbios_usb_storage_devices:
-	DEFW +0x0000
 	DEFB +0x00
 	DEFB +0x00
 	DEFB 0x00
@@ -102,13 +98,3 @@ _hbios_usb_storage_devices:
 	DEFB 0x00
 	DEFB 0x00
 	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
diff --git a/Source/HBIOS/ch376-native/base-drv/usb-base-drv.c.s b/Source/HBIOS/ch376-native/base-drv/usb-base-drv.c.s
index 8006021c..f8e7284e 100644
--- a/Source/HBIOS/ch376-native/base-drv/usb-base-drv.c.s
+++ b/Source/HBIOS/ch376-native/base-drv/usb-base-drv.c.s
@@ -48,35 +48,27 @@ _USB_MODULE_LEDS	.EQU	0xff8a
 ;--------------------------------------------------------
 ; code
 ;--------------------------------------------------------
-;source-doc/base-drv/usb-base-drv.c:3: uint8_t chnative_seek(const uint32_t lba, device_config_storage *const storage_device) __sdcccall(1) {
+;source-doc/base-drv/usb-base-drv.c:4: uint8_t scsi_seek(const uint16_t dev_index, const uint32_t lba) {
 ; ---------------------------------
-; Function chnative_seek
+; Function scsi_seek
 ; ---------------------------------
-_chnative_seek:
+_scsi_seek:
 	push	ix
 	ld	ix,0
 	add	ix,sp
-	ld	c, l
-	ld	b, h
-;source-doc/base-drv/usb-base-drv.c:4: storage_device->current_lba = lba;
-	ld	h,(ix+5)
+;source-doc/base-drv/usb-base-drv.c:5: device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
 	ld	a,(ix+4)
-	add	a,0x0c
-	ld	l, a
-	jr	NC,l_chnative_seek_00103
-	inc	h
-l_chnative_seek_00103:
-	ld	(hl), e
-	inc	hl
-	ld	(hl), d
-	inc	hl
-	ld	(hl), c
-	inc	hl
-	ld	(hl), b
-;source-doc/base-drv/usb-base-drv.c:5: return 0;
-	xor	a
-;source-doc/base-drv/usb-base-drv.c:6: }
+	call	_get_usb_device_config
+;source-doc/base-drv/usb-base-drv.c:7: dev->current_lba = lba;
+	ld	hl,0x000c
+	add	hl, de
+	ex	de, hl
+	ld	hl,6
+	add	hl, sp
+	ld	bc,0x0004
+	ldir
+;source-doc/base-drv/usb-base-drv.c:8: return 0;
+	ld	l,0x00
+;source-doc/base-drv/usb-base-drv.c:9: }
 	pop	ix
-	pop	hl
-	pop	bc
-	jp	(hl)
+	ret
diff --git a/Source/HBIOS/ch376-native/base-drv/usb_init.c.s b/Source/HBIOS/ch376-native/base-drv/usb_init.c.s
index 1d3054c2..a8b35de0 100644
--- a/Source/HBIOS/ch376-native/base-drv/usb_init.c.s
+++ b/Source/HBIOS/ch376-native/base-drv/usb_init.c.s
@@ -169,7 +169,7 @@ l_usb_init_00108:
 	jr	l_usb_init_00113
 l_usb_init_00110:
 ;source-doc/base-drv/usb_init.c:61: memset(get_usb_work_area(), 0, sizeof(_usb_state));
-	ld	b,0x35
+	ld	b,0x32
 	ld	hl,_x
 	jr	l_usb_init_00163
 l_usb_init_00162:
diff --git a/Source/HBIOS/ch376-native/base-drv/usb_state.c.s b/Source/HBIOS/ch376-native/base-drv/usb_state.c.s
index 660e8572..6c8e49a5 100644
--- a/Source/HBIOS/ch376-native/base-drv/usb_state.c.s
+++ b/Source/HBIOS/ch376-native/base-drv/usb_state.c.s
@@ -89,8 +89,8 @@ l_count_of_devices_00106:
 	ret
 _device_config_sizes:
 	DEFB +0x00
-	DEFB +0x11
-	DEFB +0x11
+	DEFB +0x10
+	DEFB +0x10
 	DEFB +0x0c
 	DEFB +0x06
 	DEFB 0x00
@@ -174,7 +174,7 @@ l_next_device_config_00102:
 	adc	a, d
 	ld	d, a
 ;source-doc/base-drv/usb_state.c:64: if (result >= (device_config *)&usb_state->device_configs_end)
-	ld	hl,0x0068
+	ld	hl,0x0062
 	add	hl, bc
 	ld	a, e
 	sub	l
diff --git a/Source/HBIOS/ch376-native/base-drv/work-area.c.s b/Source/HBIOS/ch376-native/base-drv/work-area.c.s
index 0449816b..e08c9fe6 100644
--- a/Source/HBIOS/ch376-native/base-drv/work-area.c.s
+++ b/Source/HBIOS/ch376-native/base-drv/work-area.c.s
@@ -34,7 +34,7 @@ _USB_MODULE_LEDS	.EQU	0xff8a
 ; .area _INITIALIZED removed by z88dk
 	
 _x:
-	DEFS 105
+	DEFS 99
 	
 #ENDIF
 	
@@ -149,10 +149,4 @@ _x:
 	DEFB 0x00
 	DEFB 0x00
 	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
-	DEFB 0x00
 	DEFB +0x00
diff --git a/Source/HBIOS/ch376-native/scsi-drv/class_scsi.c.s b/Source/HBIOS/ch376-native/scsi-drv/class_scsi.c.s
index a56b867a..02c7bc98 100644
--- a/Source/HBIOS/ch376-native/scsi-drv/class_scsi.c.s
+++ b/Source/HBIOS/ch376-native/scsi-drv/class_scsi.c.s
@@ -41,8 +41,6 @@ _csw:
 	DEFS 13
 _scsi_packet_read_capacity:
 	DEFS 12
-_scsi_packet_inquiry:
-	DEFS 12
 _scsi_packet_request_sense:
 	DEFS 12
 _cbw:
@@ -297,7 +295,7 @@ l_do_scsi_cmd_00120:
 	ld	sp, ix
 	pop	ix
 	ret
-;source-doc/scsi-drv/class_scsi.c:54: usb_error scsi_read_capacity(device_config_storage *const dev, scsi_read_capacity_result *cap_result) {
+;source-doc/scsi-drv/class_scsi.c:54: usb_error scsi_read_capacity(const uint16_t dev_index, scsi_read_capacity_result *cap_result) {
 ; ---------------------------------
 ; Function scsi_read_capacity
 ; ---------------------------------
@@ -308,114 +306,58 @@ _scsi_read_capacity:
 	ld	hl, -27
 	add	hl, sp
 	ld	sp, hl
-;source-doc/scsi-drv/class_scsi.c:56: cbw_scsi.cbw           = scsi_command_block_wrapper;
-	ld	hl,0
+;source-doc/scsi-drv/class_scsi.c:55: device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+	ld	a,(ix+4)
+	call	_get_usb_device_config
+;source-doc/scsi-drv/class_scsi.c:58: cbw_scsi.cbw           = scsi_command_block_wrapper;
+	push	de
+	ld	hl,2
 	add	hl, sp
-	ld	e,l
-	ld	d,h
-	push	hl
+	ex	de, hl
 	ld	bc,0x000f
 	ld	hl,_scsi_command_block_wrapper
 	ldir
-;source-doc/scsi-drv/class_scsi.c:57: cbw_scsi.read_capacity = scsi_packet_read_capacity;
+	pop	de
+;source-doc/scsi-drv/class_scsi.c:59: cbw_scsi.read_capacity = scsi_packet_read_capacity;
+	push	de
 	ld	hl,17
 	add	hl, sp
 	ex	de, hl
 	ld	bc,0x000c
 	ld	hl,_scsi_packet_read_capacity
 	ldir
-	pop	bc
-;source-doc/scsi-drv/class_scsi.c:59: cbw_scsi.cbw.bCBWLUN                = 0;
+	pop	de
+;source-doc/scsi-drv/class_scsi.c:61: cbw_scsi.cbw.bCBWLUN                = 0;
 	ld	(ix-14),0x00
-;source-doc/scsi-drv/class_scsi.c:60: cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_read_capacity);
+;source-doc/scsi-drv/class_scsi.c:62: cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_read_capacity);
 	ld	(ix-13),0x0c
-;source-doc/scsi-drv/class_scsi.c:61: cbw_scsi.cbw.dCBWDataTransferLength = sizeof(scsi_read_capacity_result);
-	ld	hl,0x0008
-	add	hl, bc
-	ld	(hl),0x08
-	inc	hl
+;source-doc/scsi-drv/class_scsi.c:63: cbw_scsi.cbw.dCBWDataTransferLength = sizeof(scsi_read_capacity_result);
+	ld	(ix-19),0x08
 	xor	a
-	ld	(hl), a
-	inc	hl
-	ld	(hl), a
-	inc	hl
-	ld	(hl), a
-;source-doc/scsi-drv/class_scsi.c:63: return do_scsi_cmd(dev, &cbw_scsi.cbw, cap_result, false);
-	ld	e,(ix+6)
-	ld	d,(ix+7)
+	ld	(ix-18),a
+	ld	(ix-17),a
+	ld	(ix-16),a
+;source-doc/scsi-drv/class_scsi.c:65: return do_scsi_cmd(dev, &cbw_scsi.cbw, cap_result, false);
+	ld	c,(ix+6)
+	ld	b,(ix+7)
 	xor	a
 	push	af
 	inc	sp
-	push	de
 	push	bc
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	push	hl
-	call	_do_scsi_cmd
-;source-doc/scsi-drv/class_scsi.c:64: }
-	ld	sp,ix
-	pop	ix
-	ret
-;source-doc/scsi-drv/class_scsi.c:68: usb_error scsi_inquiry(device_config_storage *const dev, scsi_inquiry_result *inq_result) {
-; ---------------------------------
-; Function scsi_inquiry
-; ---------------------------------
-_scsi_inquiry:
-	push	ix
-	ld	ix,0
-	add	ix,sp
-	ld	hl, -27
+	ld	hl,3
 	add	hl, sp
-	ld	sp, hl
-;source-doc/scsi-drv/class_scsi.c:70: cbw_scsi.cbw     = scsi_command_block_wrapper;
-	ld	hl,0
-	add	hl, sp
-	ld	e,l
-	ld	d,h
 	push	hl
-	ld	bc,0x000f
-	ld	hl,_scsi_command_block_wrapper
-	ldir
-;source-doc/scsi-drv/class_scsi.c:71: cbw_scsi.inquiry = scsi_packet_inquiry;
-	ld	hl,17
-	add	hl, sp
-	ex	de, hl
-	ld	bc,0x000c
-	ld	hl,_scsi_packet_inquiry
-	ldir
-	pop	bc
-;source-doc/scsi-drv/class_scsi.c:73: cbw_scsi.cbw.bCBWLUN                = 0;
-	ld	(ix-14),0x00
-;source-doc/scsi-drv/class_scsi.c:74: cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_inquiry);
-	ld	(ix-13),0x0c
-;source-doc/scsi-drv/class_scsi.c:75: cbw_scsi.cbw.dCBWDataTransferLength = 0x24;
-	ld	hl,0x0008
-	add	hl, bc
-	ld	(hl),0x24
-	inc	hl
-	xor	a
-	ld	(hl), a
-	inc	hl
-	ld	(hl), a
-	inc	hl
-	ld	(hl), a
-;source-doc/scsi-drv/class_scsi.c:77: return do_scsi_cmd(dev, &cbw_scsi.cbw, inq_result, false);
-	ld	e,(ix+6)
-	ld	d,(ix+7)
-	xor	a
-	push	af
-	inc	sp
 	push	de
-	push	bc
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	push	hl
 	call	_do_scsi_cmd
-;source-doc/scsi-drv/class_scsi.c:78: }
-	ld	sp,ix
+	pop	af
+	pop	af
+	pop	af
+	inc	sp
+;source-doc/scsi-drv/class_scsi.c:66: }
+	ld	sp, ix
 	pop	ix
 	ret
-;source-doc/scsi-drv/class_scsi.c:80: usb_error scsi_test(device_config_storage *const dev) {
+;source-doc/scsi-drv/class_scsi.c:84: static usb_error scsi_test(device_config_storage *const dev) {
 ; ---------------------------------
 ; Function scsi_test
 ; ---------------------------------
@@ -426,7 +368,7 @@ _scsi_test:
 	ld	hl, -27
 	add	hl, sp
 	ld	sp, hl
-;source-doc/scsi-drv/class_scsi.c:82: cbw_scsi.cbw = scsi_command_block_wrapper;
+;source-doc/scsi-drv/class_scsi.c:86: cbw_scsi.cbw = scsi_command_block_wrapper;
 	ld	hl,0
 	add	hl, sp
 	ld	e,l
@@ -435,7 +377,7 @@ _scsi_test:
 	ld	bc,0x000f
 	ld	hl,_scsi_command_block_wrapper
 	ldir
-;source-doc/scsi-drv/class_scsi.c:83: memset(&cbw_scsi.test, 0, sizeof(_scsi_packet_test));
+;source-doc/scsi-drv/class_scsi.c:87: memset(&cbw_scsi.test, 0, sizeof(_scsi_packet_test));
 	ld	hl,17
 	add	hl, sp
 	ld	b,0x06
@@ -447,11 +389,11 @@ l_scsi_test_00103:
 	inc	hl
 	djnz	l_scsi_test_00103
 	pop	bc
-;source-doc/scsi-drv/class_scsi.c:85: cbw_scsi.cbw.bCBWLUN                = 0;
+;source-doc/scsi-drv/class_scsi.c:89: cbw_scsi.cbw.bCBWLUN                = 0;
 	ld	(ix-14),0x00
-;source-doc/scsi-drv/class_scsi.c:86: cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_test);
+;source-doc/scsi-drv/class_scsi.c:90: cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_test);
 	ld	(ix-13),0x0c
-;source-doc/scsi-drv/class_scsi.c:87: cbw_scsi.cbw.dCBWDataTransferLength = 0;
+;source-doc/scsi-drv/class_scsi.c:91: cbw_scsi.cbw.dCBWDataTransferLength = 0;
 	ld	hl,0x0008
 	add	hl, bc
 	xor	a
@@ -462,7 +404,7 @@ l_scsi_test_00103:
 	ld	(hl), a
 	inc	hl
 	ld	(hl), a
-;source-doc/scsi-drv/class_scsi.c:89: return do_scsi_cmd(dev, &cbw_scsi.cbw, 0, false);
+;source-doc/scsi-drv/class_scsi.c:93: return do_scsi_cmd(dev, &cbw_scsi.cbw, 0, false);
 	xor	a
 	push	af
 	inc	sp
@@ -473,11 +415,11 @@ l_scsi_test_00103:
 	ld	h,(ix+5)
 	push	hl
 	call	_do_scsi_cmd
-;source-doc/scsi-drv/class_scsi.c:90: }
+;source-doc/scsi-drv/class_scsi.c:94: }
 	ld	sp,ix
 	pop	ix
 	ret
-;source-doc/scsi-drv/class_scsi.c:94: usb_error scsi_request_sense(device_config_storage *const dev, scsi_sense_result *const sens_result) {
+;source-doc/scsi-drv/class_scsi.c:98: static usb_error scsi_request_sense(device_config_storage *const dev, scsi_sense_result *const sens_result) {
 ; ---------------------------------
 ; Function scsi_request_sense
 ; ---------------------------------
@@ -488,7 +430,7 @@ _scsi_request_sense:
 	ld	hl, -27
 	add	hl, sp
 	ld	sp, hl
-;source-doc/scsi-drv/class_scsi.c:96: cbw_scsi.cbw           = scsi_command_block_wrapper;
+;source-doc/scsi-drv/class_scsi.c:100: cbw_scsi.cbw           = scsi_command_block_wrapper;
 	ld	hl,0
 	add	hl, sp
 	ld	e,l
@@ -497,7 +439,7 @@ _scsi_request_sense:
 	ld	bc,0x000f
 	ld	hl,_scsi_command_block_wrapper
 	ldir
-;source-doc/scsi-drv/class_scsi.c:97: cbw_scsi.request_sense = scsi_packet_request_sense;
+;source-doc/scsi-drv/class_scsi.c:101: cbw_scsi.request_sense = scsi_packet_request_sense;
 	ld	hl,17
 	add	hl, sp
 	ex	de, hl
@@ -505,11 +447,11 @@ _scsi_request_sense:
 	ld	hl,_scsi_packet_request_sense
 	ldir
 	pop	bc
-;source-doc/scsi-drv/class_scsi.c:99: cbw_scsi.cbw.bCBWLUN                = 0;
+;source-doc/scsi-drv/class_scsi.c:103: cbw_scsi.cbw.bCBWLUN                = 0;
 	ld	(ix-14),0x00
-;source-doc/scsi-drv/class_scsi.c:100: cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_request_sense);
+;source-doc/scsi-drv/class_scsi.c:104: cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_request_sense);
 	ld	(ix-13),0x0c
-;source-doc/scsi-drv/class_scsi.c:101: cbw_scsi.cbw.dCBWDataTransferLength = sizeof(scsi_sense_result);
+;source-doc/scsi-drv/class_scsi.c:105: cbw_scsi.cbw.dCBWDataTransferLength = sizeof(scsi_sense_result);
 	ld	hl,0x0008
 	add	hl, bc
 	ld	(hl),0x12
@@ -520,7 +462,7 @@ _scsi_request_sense:
 	ld	(hl), a
 	inc	hl
 	ld	(hl), a
-;source-doc/scsi-drv/class_scsi.c:103: return do_scsi_cmd(dev, &cbw_scsi.cbw, sens_result, false);
+;source-doc/scsi-drv/class_scsi.c:107: return do_scsi_cmd(dev, &cbw_scsi.cbw, sens_result, false);
 	ld	e,(ix+6)
 	ld	d,(ix+7)
 	xor	a
@@ -532,11 +474,11 @@ _scsi_request_sense:
 	ld	h,(ix+5)
 	push	hl
 	call	_do_scsi_cmd
-;source-doc/scsi-drv/class_scsi.c:104: }
+;source-doc/scsi-drv/class_scsi.c:108: }
 	ld	sp,ix
 	pop	ix
 	ret
-;source-doc/scsi-drv/class_scsi.c:106: usb_error scsi_sense_init(device_config_storage *const dev) {
+;source-doc/scsi-drv/class_scsi.c:110: usb_error scsi_sense_init(const uint16_t dev_index) {
 ; ---------------------------------
 ; Function scsi_sense_init
 ; ---------------------------------
@@ -547,62 +489,52 @@ _scsi_sense_init:
 	ld	hl, -18
 	add	hl, sp
 	ld	sp, hl
-;source-doc/scsi-drv/class_scsi.c:110: critical_begin();
+;source-doc/scsi-drv/class_scsi.c:111: device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+	ld	a,(ix+4)
+	call	_get_usb_device_config
+;source-doc/scsi-drv/class_scsi.c:116: critical_begin();
+	push	de
 	call	_critical_begin
-;source-doc/scsi-drv/class_scsi.c:111: while ((result = scsi_test(dev)) && --counter > 0)
+	pop	de
+;source-doc/scsi-drv/class_scsi.c:117: while ((result = scsi_test(dev)) && --counter > 0)
 	ld	c,0x03
 l_scsi_sense_init_00102:
 	push	bc
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	push	hl
+	push	de
+	push	de
 	call	_scsi_test
 	pop	af
 	ld	a, l
+	pop	de
 	pop	bc
 	ld	(_result),a
 	or	a
 	jr	Z,l_scsi_sense_init_00104
 	dec	c
 	jr	Z,l_scsi_sense_init_00104
-;source-doc/scsi-drv/class_scsi.c:112: scsi_request_sense(dev, &response);
+;source-doc/scsi-drv/class_scsi.c:118: scsi_request_sense(dev, &response);
 	ld	hl,0
 	add	hl, sp
 	push	bc
+	push	de
 	push	hl
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	push	hl
+	push	de
 	call	_scsi_request_sense
 	pop	af
 	pop	af
+	pop	de
 	pop	bc
 	jr	l_scsi_sense_init_00102
 l_scsi_sense_init_00104:
-;source-doc/scsi-drv/class_scsi.c:113: critical_end();
+;source-doc/scsi-drv/class_scsi.c:119: critical_end();
 	call	_critical_end
-;source-doc/scsi-drv/class_scsi.c:115: return result;
+;source-doc/scsi-drv/class_scsi.c:121: return result;
 	ld	hl, (_result)
-;source-doc/scsi-drv/class_scsi.c:116: }
+;source-doc/scsi-drv/class_scsi.c:122: }
 	ld	sp, ix
 	pop	ix
 	ret
-;source-doc/scsi-drv/class_scsi.c:120: void spike_x(void) {
-; ---------------------------------
-; Function spike_x
-; ---------------------------------
-_spike_x:
-;source-doc/scsi-drv/class_scsi.c:121: scsi_read(5, NULL);
-	ld	hl,0x0000
-	push	hl
-	ld	l,0x05
-	push	hl
-	call	_scsi_read
-	pop	af
-	pop	af
-;source-doc/scsi-drv/class_scsi.c:122: }
-	ret
-;source-doc/scsi-drv/class_scsi.c:124: usb_error scsi_read(const uint16_t dev_index, uint8_t *const buffer)  {
+;source-doc/scsi-drv/class_scsi.c:126: usb_error scsi_read(const uint16_t dev_index, uint8_t *const buffer) {
 ; ---------------------------------
 ; Function scsi_read
 ; ---------------------------------
@@ -611,12 +543,12 @@ _scsi_read:
 	ld	ix,0
 	add	ix,sp
 	push	af
-;source-doc/scsi-drv/class_scsi.c:125: device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+;source-doc/scsi-drv/class_scsi.c:127: device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
 	ld	a,(ix+4)
 	call	_get_usb_device_config
 	pop	bc
 	push	de
-;source-doc/scsi-drv/class_scsi.c:127: memset(&cbw, 0, sizeof(cbw_scsi_read_write));
+;source-doc/scsi-drv/class_scsi.c:129: memset(&cbw, 0, sizeof(cbw_scsi_read_write));
 	ld	de,_cbw
 	ld	l, e
 	ld	h, d
@@ -629,28 +561,28 @@ l_scsi_read_00113:
 	ld	(hl),0x00
 	inc	hl
 	djnz	l_scsi_read_00112
-;source-doc/scsi-drv/class_scsi.c:128: cbw.cbw = scsi_command_block_wrapper;
+;source-doc/scsi-drv/class_scsi.c:130: cbw.cbw = scsi_command_block_wrapper;
 	ld	bc,0x000f
 	ld	hl,_scsi_command_block_wrapper
 	ldir
-;source-doc/scsi-drv/class_scsi.c:130: cbw.cbw.bCBWLUN                = 0;
+;source-doc/scsi-drv/class_scsi.c:132: cbw.cbw.bCBWLUN                = 0;
 	ld	hl,_cbw + 13
 	ld	(hl),0x00
-;source-doc/scsi-drv/class_scsi.c:131: cbw.cbw.bCBWCBLength           = sizeof(_scsi_packet_read_write);
+;source-doc/scsi-drv/class_scsi.c:133: cbw.cbw.bCBWCBLength           = sizeof(_scsi_packet_read_write);
 	ld	hl,_cbw + 14
 	ld	(hl),0x0c
-;source-doc/scsi-drv/class_scsi.c:132: cbw.cbw.dCBWDataTransferLength = 512;
+;source-doc/scsi-drv/class_scsi.c:134: cbw.cbw.dCBWDataTransferLength = 512;
 	ld	hl,0x0200
 	ld	(_cbw + 8),hl
 	ld	h, l
 	ld	(_cbw + 8 + 2),hl
-;source-doc/scsi-drv/class_scsi.c:134: cbw.scsi_cmd.operation_code  = 0x28; // read operation
+;source-doc/scsi-drv/class_scsi.c:136: cbw.scsi_cmd.operation_code  = 0x28; // read operation
 	ld	hl,_cbw + 15
 	ld	(hl),0x28
-;source-doc/scsi-drv/class_scsi.c:135: cbw.scsi_cmd.transfer_len[1] = 1;
+;source-doc/scsi-drv/class_scsi.c:137: cbw.scsi_cmd.transfer_len[1] = 1;
 	ld	hl,_cbw + 23
 	ld	(hl),0x01
-;source-doc/scsi-drv/class_scsi.c:136: cbw.scsi_cmd.lba[0]          = dev->current_lba >> 24;
+;source-doc/scsi-drv/class_scsi.c:138: cbw.scsi_cmd.lba[0]          = dev->current_lba >> 24;
 	ld	l,(ix-2)
 	ld	h,(ix-1)
 	ld	bc,0x000c
@@ -662,8 +594,8 @@ l_scsi_read_00113:
 	inc	hl
 	ld	a, (hl)
 	ld	((_cbw + 17)),a
-;source-doc/scsi-drv/class_scsi.c:137: cbw.scsi_cmd.lba[1]          = dev->current_lba >> 16;
-;source-doc/scsi-drv/class_scsi.c:138: cbw.scsi_cmd.lba[2]          = dev->current_lba >> 8;
+;source-doc/scsi-drv/class_scsi.c:139: cbw.scsi_cmd.lba[1]          = dev->current_lba >> 16;
+;source-doc/scsi-drv/class_scsi.c:140: cbw.scsi_cmd.lba[2]          = dev->current_lba >> 8;
 	ld	l,c
 	ld	h,b
 	inc	hl
@@ -674,11 +606,11 @@ l_scsi_read_00113:
 	ld	e, (hl)
 	ld	hl, +(_cbw + 19)
 	ld	(hl), e
-;source-doc/scsi-drv/class_scsi.c:139: cbw.scsi_cmd.lba[3]          = dev->current_lba;
+;source-doc/scsi-drv/class_scsi.c:141: cbw.scsi_cmd.lba[3]          = dev->current_lba;
 	ld	a, (bc)
 	inc	hl
 	ld	(hl), a
-;source-doc/scsi-drv/class_scsi.c:141: result = do_scsi_cmd(dev, &cbw.cbw, buffer, false);
+;source-doc/scsi-drv/class_scsi.c:143: result = do_scsi_cmd(dev, &cbw.cbw, buffer, false);
 	ld	e,(ix+6)
 	ld	d,(ix+7)
 	push	bc
@@ -699,11 +631,11 @@ l_scsi_read_00113:
 	pop	bc
 	ld	a, l
 	ld	(_result), a
-;source-doc/scsi-drv/class_scsi.c:143: if (result == USB_ERR_OK)
+;source-doc/scsi-drv/class_scsi.c:145: if (result == USB_ERR_OK)
 	ld	a,(_result)
 	or	a
 	jr	NZ,l_scsi_read_00102
-;source-doc/scsi-drv/class_scsi.c:144: dev->current_lba++;
+;source-doc/scsi-drv/class_scsi.c:146: dev->current_lba++;
 	ld	l, c
 	ld	h, b
 	ld	e, (hl)
@@ -732,13 +664,13 @@ l_scsi_read_00114:
 	ld	a, h
 	ld	(bc), a
 l_scsi_read_00102:
-;source-doc/scsi-drv/class_scsi.c:145: return result;
+;source-doc/scsi-drv/class_scsi.c:147: return result;
 	ld	hl, (_result)
-;source-doc/scsi-drv/class_scsi.c:146: }
+;source-doc/scsi-drv/class_scsi.c:148: }
 	ld	sp, ix
 	pop	ix
 	ret
-;source-doc/scsi-drv/class_scsi.c:148: usb_error scsi_write(device_config_storage *const dev, uint8_t *const buffer) {
+;source-doc/scsi-drv/class_scsi.c:150: usb_error scsi_write(const uint16_t dev_index, uint8_t *const buffer) {
 ; ---------------------------------
 ; Function scsi_write
 ; ---------------------------------
@@ -746,7 +678,13 @@ _scsi_write:
 	push	ix
 	ld	ix,0
 	add	ix,sp
-;source-doc/scsi-drv/class_scsi.c:149: memset(&cbw, 0, sizeof(cbw_scsi_read_write));
+	push	af
+;source-doc/scsi-drv/class_scsi.c:151: device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+	ld	a,(ix+4)
+	call	_get_usb_device_config
+	pop	bc
+	push	de
+;source-doc/scsi-drv/class_scsi.c:153: memset(&cbw, 0, sizeof(cbw_scsi_read_write));
 	ld	de,_cbw
 	ld	l, e
 	ld	h, d
@@ -759,30 +697,30 @@ l_scsi_write_00113:
 	ld	(hl),0x00
 	inc	hl
 	djnz	l_scsi_write_00112
-;source-doc/scsi-drv/class_scsi.c:150: cbw.cbw = scsi_command_block_wrapper;
+;source-doc/scsi-drv/class_scsi.c:154: cbw.cbw = scsi_command_block_wrapper;
 	ld	bc,0x000f
 	ld	hl,_scsi_command_block_wrapper
 	ldir
-;source-doc/scsi-drv/class_scsi.c:152: cbw.cbw.bCBWLUN                = 0;
+;source-doc/scsi-drv/class_scsi.c:156: cbw.cbw.bCBWLUN                = 0;
 	ld	hl,_cbw + 13
 	ld	(hl),0x00
-;source-doc/scsi-drv/class_scsi.c:153: cbw.cbw.bCBWCBLength           = sizeof(_scsi_packet_read_write);
+;source-doc/scsi-drv/class_scsi.c:157: cbw.cbw.bCBWCBLength           = sizeof(_scsi_packet_read_write);
 	ld	hl,_cbw + 14
 	ld	(hl),0x0c
-;source-doc/scsi-drv/class_scsi.c:154: cbw.cbw.dCBWDataTransferLength = 512;
+;source-doc/scsi-drv/class_scsi.c:158: cbw.cbw.dCBWDataTransferLength = 512;
 	ld	hl,0x0200
 	ld	(_cbw + 8),hl
 	ld	h, l
 	ld	(_cbw + 8 + 2),hl
-;source-doc/scsi-drv/class_scsi.c:156: cbw.scsi_cmd.operation_code  = 0x2A; // write operation
+;source-doc/scsi-drv/class_scsi.c:160: cbw.scsi_cmd.operation_code  = 0x2A; // write operation
 	ld	hl,_cbw + 15
 	ld	(hl),0x2a
-;source-doc/scsi-drv/class_scsi.c:157: cbw.scsi_cmd.transfer_len[1] = 1;
+;source-doc/scsi-drv/class_scsi.c:161: cbw.scsi_cmd.transfer_len[1] = 1;
 	ld	hl,_cbw + 23
 	ld	(hl),0x01
-;source-doc/scsi-drv/class_scsi.c:158: cbw.scsi_cmd.lba[0]          = dev->current_lba >> 24;
-	ld	l,(ix+4)
-	ld	h,(ix+5)
+;source-doc/scsi-drv/class_scsi.c:162: cbw.scsi_cmd.lba[0]          = dev->current_lba >> 24;
+	ld	l,(ix-2)
+	ld	h,(ix-1)
 	ld	bc,0x000c
 	add	hl,bc
 	ld	c,l
@@ -792,8 +730,8 @@ l_scsi_write_00113:
 	inc	hl
 	ld	a, (hl)
 	ld	((_cbw + 17)),a
-;source-doc/scsi-drv/class_scsi.c:159: cbw.scsi_cmd.lba[1]          = dev->current_lba >> 16;
-;source-doc/scsi-drv/class_scsi.c:160: cbw.scsi_cmd.lba[2]          = dev->current_lba >> 8;
+;source-doc/scsi-drv/class_scsi.c:163: cbw.scsi_cmd.lba[1]          = dev->current_lba >> 16;
+;source-doc/scsi-drv/class_scsi.c:164: cbw.scsi_cmd.lba[2]          = dev->current_lba >> 8;
 	ld	l,c
 	ld	h,b
 	inc	hl
@@ -804,11 +742,11 @@ l_scsi_write_00113:
 	ld	e, (hl)
 	ld	hl, +(_cbw + 19)
 	ld	(hl), e
-;source-doc/scsi-drv/class_scsi.c:161: cbw.scsi_cmd.lba[3]          = dev->current_lba;
+;source-doc/scsi-drv/class_scsi.c:165: cbw.scsi_cmd.lba[3]          = dev->current_lba;
 	ld	a, (bc)
 	inc	hl
 	ld	(hl), a
-;source-doc/scsi-drv/class_scsi.c:163: result = do_scsi_cmd(dev, &cbw.cbw, buffer, true);
+;source-doc/scsi-drv/class_scsi.c:167: result = do_scsi_cmd(dev, &cbw.cbw, buffer, true);
 	ld	e,(ix+6)
 	ld	d,(ix+7)
 	push	bc
@@ -818,8 +756,8 @@ l_scsi_write_00113:
 	push	de
 	ld	hl,_cbw
 	push	hl
-	ld	l,(ix+4)
-	ld	h,(ix+5)
+	ld	l,(ix-2)
+	ld	h,(ix-1)
 	push	hl
 	call	_do_scsi_cmd
 	pop	af
@@ -829,11 +767,11 @@ l_scsi_write_00113:
 	pop	bc
 	ld	a, l
 	ld	(_result), a
-;source-doc/scsi-drv/class_scsi.c:165: if (result == USB_ERR_OK)
+;source-doc/scsi-drv/class_scsi.c:169: if (result == USB_ERR_OK)
 	ld	a,(_result)
 	or	a
 	jr	NZ,l_scsi_write_00102
-;source-doc/scsi-drv/class_scsi.c:166: dev->current_lba++;
+;source-doc/scsi-drv/class_scsi.c:170: dev->current_lba++;
 	ld	l, c
 	ld	h, b
 	ld	e, (hl)
@@ -862,77 +800,10 @@ l_scsi_write_00114:
 	ld	a, h
 	ld	(bc), a
 l_scsi_write_00102:
-;source-doc/scsi-drv/class_scsi.c:167: return result;
+;source-doc/scsi-drv/class_scsi.c:171: return result;
 	ld	hl, (_result)
-;source-doc/scsi-drv/class_scsi.c:168: }
-	pop	ix
-	ret
-;source-doc/scsi-drv/class_scsi.c:170: usb_error scsi_eject(device_config_storage *const dev) {
-; ---------------------------------
-; Function scsi_eject
-; ---------------------------------
-_scsi_eject:
-	push	ix
-	ld	ix,0
-	add	ix,sp
-	ld	hl, -21
-	add	hl, sp
-	ld	sp, hl
-;source-doc/scsi-drv/class_scsi.c:172: cbw_scsi.cbw = scsi_command_block_wrapper;
-	ld	hl,0
-	add	hl, sp
-	ld	e,l
-	ld	d,h
-	push	hl
-	ld	bc,0x000f
-	ld	hl,_scsi_command_block_wrapper
-	ldir
-;source-doc/scsi-drv/class_scsi.c:174: memset(&cbw_scsi.eject, 0, sizeof(_scsi_packet_eject));
-	ld	hl,17
-	add	hl, sp
-	ld	b,0x03
-l_scsi_eject_00103:
-	xor	a
-	ld	(hl), a
-	inc	hl
-	ld	(hl), a
-	inc	hl
-	djnz	l_scsi_eject_00103
-	pop	bc
-;source-doc/scsi-drv/class_scsi.c:176: cbw_scsi.eject.operation_code = 0x1B;
-	ld	(ix-6),0x1b
-;source-doc/scsi-drv/class_scsi.c:177: cbw_scsi.eject.loej           = 1;
-	ld	hl,19
-	add	hl, sp
-	set	1, (hl)
-;source-doc/scsi-drv/class_scsi.c:179: cbw_scsi.cbw.bCBWLUN                = 0;
-	ld	(ix-8),0x00
-;source-doc/scsi-drv/class_scsi.c:180: cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_eject);
-	ld	(ix-7),0x06
-;source-doc/scsi-drv/class_scsi.c:181: cbw_scsi.cbw.dCBWDataTransferLength = 0;
-	ld	hl,0x0008
-	add	hl, bc
-	xor	a
-	ld	(hl), a
-	inc	hl
-	ld	(hl), a
-	inc	hl
-	ld	(hl), a
-	inc	hl
-	ld	(hl), a
-;source-doc/scsi-drv/class_scsi.c:183: return do_scsi_cmd(dev, &cbw_scsi.cbw, 0, false);
-	xor	a
-	push	af
-	inc	sp
-	ld	hl,0x0000
-	push	hl
-	push	bc
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	push	hl
-	call	_do_scsi_cmd
-;source-doc/scsi-drv/class_scsi.c:184: }
-	ld	sp,ix
+;source-doc/scsi-drv/class_scsi.c:172: }
+	ld	sp, ix
 	pop	ix
 	ret
 _scsi_command_block_wrapper:
@@ -975,19 +846,6 @@ _scsi_packet_read_capacity:
 	DEFB +0x00
 	DEFB +0x00
 	DEFB +0x00
-_scsi_packet_inquiry:
-	DEFB +0x12
-	DEFB +0x00
-	DEFB +0x00
-	DEFB +0x00
-	DEFB +0x24
-	DEFB +0x00
-	DEFB +0x00
-	DEFB +0x00
-	DEFB +0x00
-	DEFB +0x00
-	DEFB +0x00
-	DEFB +0x00
 _scsi_packet_request_sense:
 	DEFB +0x03
 	DEFB +0x00
diff --git a/Source/HBIOS/ch376-native/scsi-drv/scsi-init.c.s b/Source/HBIOS/ch376-native/scsi-drv/scsi-init.c.s
index 147acfaa..904c8ba8 100644
--- a/Source/HBIOS/ch376-native/scsi-drv/scsi-init.c.s
+++ b/Source/HBIOS/ch376-native/scsi-drv/scsi-init.c.s
@@ -56,104 +56,90 @@ _chscsi_init:
 	push	ix
 	ld	ix,0
 	add	ix,sp
-	ld	hl, -5
-	add	hl, sp
-	ld	sp, hl
+	push	af
+	dec	sp
 ;source-doc/scsi-drv/scsi-init.c:16: do {
 	ld	(ix-1),0x01
 l_chscsi_init_00105:
 ;source-doc/scsi-drv/scsi-init.c:17: device_config_storage *const storage_device = (device_config_storage *)get_usb_device_config(index);
 	ld	a,(ix-1)
 	call	_get_usb_device_config
+	ld	l, e
 ;source-doc/scsi-drv/scsi-init.c:19: if (storage_device == NULL)
-	ld	a, d
+	ld	a,d
+	ld	h,a
 	or	e
-	jp	Z, l_chscsi_init_00108
+	jr	Z,l_chscsi_init_00108
 ;source-doc/scsi-drv/scsi-init.c:22: const usb_device_type t = storage_device->type;
-	ld	l, e
-	ld	h, d
 	ld	a, (hl)
 	and	0x0f
 ;source-doc/scsi-drv/scsi-init.c:24: if (t == USB_IS_MASS_STORAGE) {
 	sub	0x02
 	jr	NZ,l_chscsi_init_00106
-;source-doc/scsi-drv/scsi-init.c:25: const uint8_t dev_index = find_storage_dev();  //index == -1 (no more left) should never happen
-	push	de
+;source-doc/scsi-drv/scsi-init.c:25: const uint8_t dev_index                          = find_storage_dev(); // index == -1 (no more left) should never happen
 	call	_find_storage_dev
-	ld	c, l
-	pop	de
-;source-doc/scsi-drv/scsi-init.c:26: hbios_usb_storage_devices[dev_index].storage_device = storage_device;
-	ld	(ix-5),c
-	ld	(ix-4),0x00
-	pop	hl
-	push	hl
-	add	hl, hl
+;source-doc/scsi-drv/scsi-init.c:26: hbios_usb_storage_devices[dev_index].drive_index = dev_index + 1;
+	ld	c,l
+	ld	e,l
+	ld	d,0x00
+	ld	h, d
 	add	hl, hl
 	ld	a, l
 	add	a, +((_hbios_usb_storage_devices) & 0xFF)
 	ld	(ix-3),a
-	ld	l,a
-	ld	a,h
-	adc	a,+((_hbios_usb_storage_devices) / 256)
+	ld	a, h
+	adc	a, +((_hbios_usb_storage_devices) / 256)
 	ld	(ix-2),a
-	ld	h,a
-	ld	(hl), e
-	inc	hl
-	ld	(hl), d
-;source-doc/scsi-drv/scsi-init.c:27: hbios_usb_storage_devices[dev_index].drive_index = dev_index + 1;
-	ld	l,(ix-3)
-	ld	h,(ix-2)
-	inc	hl
-	inc	hl
+	pop	hl
+	push	hl
 	inc	c
 	ld	(hl), c
-;source-doc/scsi-drv/scsi-init.c:28: hbios_usb_storage_devices[dev_index].usb_device = index;
-	ld	c,(ix-3)
-	ld	b,(ix-2)
-	inc	bc
-	inc	bc
+;source-doc/scsi-drv/scsi-init.c:27: hbios_usb_storage_devices[dev_index].usb_device  = index;
+	pop	bc
+	push	bc
 	inc	bc
 	ld	a,(ix-1)
 	ld	(bc), a
-;source-doc/scsi-drv/scsi-init.c:30: print_string("\r\nUSB: MASS STORAGE @ $");
+;source-doc/scsi-drv/scsi-init.c:29: print_string("\r\nUSB: MASS STORAGE @ $");
 	push	de
 	ld	hl,scsi_init_str_0
 	call	_print_string
 	pop	de
-;source-doc/scsi-drv/scsi-init.c:31: print_uint16(index);
+;source-doc/scsi-drv/scsi-init.c:30: print_uint16(index);
 	ld	l,(ix-1)
 	ld	h,0x00
+	push	hl
 	push	de
 	call	_print_uint16
-;source-doc/scsi-drv/scsi-init.c:32: print_string(":$");
+;source-doc/scsi-drv/scsi-init.c:31: print_string(":$");
 	ld	hl,scsi_init_str_1
 	call	_print_string
 	pop	de
-;source-doc/scsi-drv/scsi-init.c:33: print_uint16(dev_index + 1);
 	pop	hl
+;source-doc/scsi-drv/scsi-init.c:32: print_uint16(dev_index + 1);
+	inc	de
 	push	hl
-	inc	hl
-	push	de
+	ex	de, hl
 	call	_print_uint16
-;source-doc/scsi-drv/scsi-init.c:34: print_string(" $");
+;source-doc/scsi-drv/scsi-init.c:33: print_string(" $");
 	ld	hl,scsi_init_str_2
 	call	_print_string
-;source-doc/scsi-drv/scsi-init.c:35: scsi_sense_init(storage_device);
+;source-doc/scsi-drv/scsi-init.c:34: scsi_sense_init(index);
 	call	_scsi_sense_init
 	pop	af
-;source-doc/scsi-drv/scsi-init.c:36: dio_add_entry(ch_scsi_fntbl, &hbios_usb_storage_devices[dev_index]);
-	ld	e,(ix-3)
-	ld	d,(ix-2)
+;source-doc/scsi-drv/scsi-init.c:35: dio_add_entry(ch_scsi_fntbl, &hbios_usb_storage_devices[dev_index]);
+	pop	de
+	push	de
 	ld	hl,_ch_scsi_fntbl
 	call	_dio_add_entry
 l_chscsi_init_00106:
-;source-doc/scsi-drv/scsi-init.c:39: } while (++index != MAX_NUMBER_OF_DEVICES + 1);
+;source-doc/scsi-drv/scsi-init.c:38: } while (++index != MAX_NUMBER_OF_DEVICES + 1);
 	inc	(ix-1)
 	ld	a,(ix-1)
 	sub	0x07
-	jp	NZ,l_chscsi_init_00105
+	jr	NZ,l_chscsi_init_00105
 l_chscsi_init_00108:
-;source-doc/scsi-drv/scsi-init.c:40: }
+;source-doc/scsi-drv/scsi-init.c:39: }
 	ld	sp, ix
 	pop	ix
 	ret
diff --git a/Source/HBIOS/ch376-native/source-doc/base-drv/dev_transfers.h b/Source/HBIOS/ch376-native/source-doc/base-drv/dev_transfers.h
index cd7eaa75..54342438 100644
--- a/Source/HBIOS/ch376-native/source-doc/base-drv/dev_transfers.h
+++ b/Source/HBIOS/ch376-native/source-doc/base-drv/dev_transfers.h
@@ -39,7 +39,6 @@ typedef struct {
   COMMON_DEVICE_CONFIG             // bytes: 0-2
       endpoint_param endpoints[3]; // bytes: 3-5, 6-8, 9-11  bulk in/out and interrupt
   uint32_t           current_lba;  // bytes 12-15
-  uint8_t            drive_index;  // byte 16
 } device_config_storage;
 
 typedef struct {
diff --git a/Source/HBIOS/ch376-native/source-doc/base-drv/enumerate.c b/Source/HBIOS/ch376-native/source-doc/base-drv/enumerate.c
index aec85045..f4131d8c 100644
--- a/Source/HBIOS/ch376-native/source-doc/base-drv/enumerate.c
+++ b/Source/HBIOS/ch376-native/source-doc/base-drv/enumerate.c
@@ -186,25 +186,6 @@ done:
   return result;
 }
 
-static uint8_t count_storage_devs(enumeration_state *state) {
-
-  uint8_t index = 1;
-  do {
-    device_config_storage *const storage_device = (device_config_storage *)get_usb_device_config(index);
-
-    if (storage_device == NULL)
-      break;
-
-    const usb_device_type t = storage_device->type;
-
-    if (t == USB_IS_FLOPPY || t == USB_IS_MASS_STORAGE)
-      storage_device->drive_index = state->storage_count++;
-
-  } while (++index != MAX_NUMBER_OF_DEVICES + 1);
-
-  return state->storage_count;
-}
-
 usb_error enumerate_all_devices(void) {
   _usb_state *const work_area = get_usb_work_area();
   enumeration_state state;
@@ -212,8 +193,6 @@ usb_error enumerate_all_devices(void) {
 
   usb_error result = read_all_configs(&state);
 
-  count_storage_devs(&state);
-
   work_area->count_of_detected_usb_devices = state.next_device_address;
 
 done:
diff --git a/Source/HBIOS/ch376-native/source-doc/base-drv/hbios-driver-storage.c b/Source/HBIOS/ch376-native/source-doc/base-drv/hbios-driver-storage.c
index a5a426a4..a0b208b6 100644
--- a/Source/HBIOS/ch376-native/source-doc/base-drv/hbios-driver-storage.c
+++ b/Source/HBIOS/ch376-native/source-doc/base-drv/hbios-driver-storage.c
@@ -3,8 +3,8 @@
 hbios_storage_device_t hbios_usb_storage_devices[MAX_NUMBER_OF_DEVICES] = {{NULL}};
 
 uint8_t find_storage_dev(void) {
-  for(uint8_t i = 0; i < MAX_NUMBER_OF_DEVICES; i++)
-    if (hbios_usb_storage_devices[i].storage_device == NULL)
+  for (uint8_t i = 0; i < MAX_NUMBER_OF_DEVICES; i++)
+    if (hbios_usb_storage_devices[i].drive_index == 0)
       return i;
 
   return -1;
diff --git a/Source/HBIOS/ch376-native/source-doc/base-drv/hbios-driver-storage.h b/Source/HBIOS/ch376-native/source-doc/base-drv/hbios-driver-storage.h
index ec15480d..437bee01 100644
--- a/Source/HBIOS/ch376-native/source-doc/base-drv/hbios-driver-storage.h
+++ b/Source/HBIOS/ch376-native/source-doc/base-drv/hbios-driver-storage.h
@@ -4,7 +4,6 @@
 #include "usb_state.h"
 
 typedef struct _hbios_storage_device {
-  device_config_storage * storage_device;
   uint8_t drive_index;
   uint8_t usb_device;
 } hbios_storage_device_t;
diff --git a/Source/HBIOS/ch376-native/source-doc/base-drv/usb-base-drv.c b/Source/HBIOS/ch376-native/source-doc/base-drv/usb-base-drv.c
index 928b24f4..6f349813 100644
--- a/Source/HBIOS/ch376-native/source-doc/base-drv/usb-base-drv.c
+++ b/Source/HBIOS/ch376-native/source-doc/base-drv/usb-base-drv.c
@@ -1,6 +1,9 @@
 #include "usb-base-drv.h"
+#include "usb_state.h"
 
-uint8_t chnative_seek(const uint32_t lba, device_config_storage *const storage_device) __sdcccall(1) {
-  storage_device->current_lba = lba;
+uint8_t scsi_seek(const uint16_t dev_index, const uint32_t lba) {
+  device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+
+  dev->current_lba = lba;
   return 0;
 }
diff --git a/Source/HBIOS/ch376-native/source-doc/base-drv/usb-base-drv.h b/Source/HBIOS/ch376-native/source-doc/base-drv/usb-base-drv.h
index 3d2abd53..f5039fd2 100644
--- a/Source/HBIOS/ch376-native/source-doc/base-drv/usb-base-drv.h
+++ b/Source/HBIOS/ch376-native/source-doc/base-drv/usb-base-drv.h
@@ -1,11 +1,12 @@
 #ifndef __USB_BASE_DRV
 #define __USB_BASE_DRV
 
+#include "usb_state.h"
 #include <dev_transfers.h>
 #include <stdint.h>
 
-extern uint8_t storage_count;
-
-extern uint8_t chnative_seek(const uint32_t lba, device_config_storage *const storage_device) __sdcccall(1);
+// ufi_seek is an alias for scsi_seek
+extern usb_error scsi_seek(const uint16_t dev_index, const uint32_t lba);
+extern usb_error ufi_seek(const uint16_t dev_index, const uint32_t lba);
 
 #endif
diff --git a/Source/HBIOS/ch376-native/source-doc/scsi-drv/class_scsi.c b/Source/HBIOS/ch376-native/source-doc/scsi-drv/class_scsi.c
index 762e41c2..e5da0b94 100644
--- a/Source/HBIOS/ch376-native/source-doc/scsi-drv/class_scsi.c
+++ b/Source/HBIOS/ch376-native/source-doc/scsi-drv/class_scsi.c
@@ -51,7 +51,9 @@ done:
 
 _scsi_read_capacity scsi_packet_read_capacity = {0x25, 0, {0, 0, 0, 0, 0, 0, 0, 0}, {0, 0}};
 
-usb_error scsi_read_capacity(device_config_storage *const dev, scsi_read_capacity_result *cap_result) {
+usb_error scsi_read_capacity(const uint16_t dev_index, scsi_read_capacity_result *cap_result) {
+  device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+
   cbw_scsi_read_capacity cbw_scsi;
   cbw_scsi.cbw           = scsi_command_block_wrapper;
   cbw_scsi.read_capacity = scsi_packet_read_capacity;
@@ -63,21 +65,23 @@ usb_error scsi_read_capacity(device_config_storage *const dev, scsi_read_capacit
   return do_scsi_cmd(dev, &cbw_scsi.cbw, cap_result, false);
 }
 
-_scsi_packet_inquiry scsi_packet_inquiry = {0x12, 0, 0, 0, 0x24, 0, {0, 0, 0, 0, 0, 0}};
+// _scsi_packet_inquiry scsi_packet_inquiry = {0x12, 0, 0, 0, 0x24, 0, {0, 0, 0, 0, 0, 0}};
 
-usb_error scsi_inquiry(device_config_storage *const dev, scsi_inquiry_result *inq_result) {
-  cbw_scsi_inquiry cbw_scsi;
-  cbw_scsi.cbw     = scsi_command_block_wrapper;
-  cbw_scsi.inquiry = scsi_packet_inquiry;
+// usb_error scsi_inquiry(const uint16_t dev_index, scsi_inquiry_result *inq_result) {
+//   device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
 
-  cbw_scsi.cbw.bCBWLUN                = 0;
-  cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_inquiry);
-  cbw_scsi.cbw.dCBWDataTransferLength = 0x24;
+//   cbw_scsi_inquiry cbw_scsi;
+//   cbw_scsi.cbw     = scsi_command_block_wrapper;
+//   cbw_scsi.inquiry = scsi_packet_inquiry;
 
-  return do_scsi_cmd(dev, &cbw_scsi.cbw, inq_result, false);
-}
+//   cbw_scsi.cbw.bCBWLUN                = 0;
+//   cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_inquiry);
+//   cbw_scsi.cbw.dCBWDataTransferLength = 0x24;
 
-usb_error scsi_test(device_config_storage *const dev) {
+//   return do_scsi_cmd(dev, &cbw_scsi.cbw, inq_result, false);
+// }
+
+static usb_error scsi_test(device_config_storage *const dev) {
   cbw_scsi_test cbw_scsi;
   cbw_scsi.cbw = scsi_command_block_wrapper;
   memset(&cbw_scsi.test, 0, sizeof(_scsi_packet_test));
@@ -91,7 +95,7 @@ usb_error scsi_test(device_config_storage *const dev) {
 
 _scsi_packet_request_sense scsi_packet_request_sense = {0x03, 0, 0, 0, 18, 0, {0, 0, 0, 0, 0, 0}};
 
-usb_error scsi_request_sense(device_config_storage *const dev, scsi_sense_result *const sens_result) {
+static usb_error scsi_request_sense(device_config_storage *const dev, scsi_sense_result *const sens_result) {
   cbw_scsi_request_sense cbw_scsi;
   cbw_scsi.cbw           = scsi_command_block_wrapper;
   cbw_scsi.request_sense = scsi_packet_request_sense;
@@ -103,7 +107,9 @@ usb_error scsi_request_sense(device_config_storage *const dev, scsi_sense_result
   return do_scsi_cmd(dev, &cbw_scsi.cbw, sens_result, false);
 }
 
-usb_error scsi_sense_init(device_config_storage *const dev) {
+usb_error scsi_sense_init(const uint16_t dev_index) {
+  device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+
   scsi_sense_result response;
   uint8_t           counter = 3;
 
@@ -117,11 +123,7 @@ usb_error scsi_sense_init(device_config_storage *const dev) {
 
 static cbw_scsi_read_write cbw = {{{0}}};
 
-void spike_x(void) {
-  scsi_read(5, NULL);
-}
-
-usb_error scsi_read(const uint16_t dev_index, uint8_t *const buffer)  {
+usb_error scsi_read(const uint16_t dev_index, uint8_t *const buffer) {
   device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
 
   memset(&cbw, 0, sizeof(cbw_scsi_read_write));
@@ -145,7 +147,9 @@ usb_error scsi_read(const uint16_t dev_index, uint8_t *const buffer)  {
   return result;
 }
 
-usb_error scsi_write(device_config_storage *const dev, uint8_t *const buffer) {
+usb_error scsi_write(const uint16_t dev_index, uint8_t *const buffer) {
+  device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+
   memset(&cbw, 0, sizeof(cbw_scsi_read_write));
   cbw.cbw = scsi_command_block_wrapper;
 
@@ -167,18 +171,18 @@ usb_error scsi_write(device_config_storage *const dev, uint8_t *const buffer) {
   return result;
 }
 
-usb_error scsi_eject(device_config_storage *const dev) {
-  cbw_scsi_eject cbw_scsi;
-  cbw_scsi.cbw = scsi_command_block_wrapper;
+// usb_error scsi_eject(device_config_storage *const dev) {
+//   cbw_scsi_eject cbw_scsi;
+//   cbw_scsi.cbw = scsi_command_block_wrapper;
 
-  memset(&cbw_scsi.eject, 0, sizeof(_scsi_packet_eject));
+//   memset(&cbw_scsi.eject, 0, sizeof(_scsi_packet_eject));
 
-  cbw_scsi.eject.operation_code = 0x1B;
-  cbw_scsi.eject.loej           = 1;
+//   cbw_scsi.eject.operation_code = 0x1B;
+//   cbw_scsi.eject.loej           = 1;
 
-  cbw_scsi.cbw.bCBWLUN                = 0;
-  cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_eject);
-  cbw_scsi.cbw.dCBWDataTransferLength = 0;
+//   cbw_scsi.cbw.bCBWLUN                = 0;
+//   cbw_scsi.cbw.bCBWCBLength           = sizeof(_scsi_packet_eject);
+//   cbw_scsi.cbw.dCBWDataTransferLength = 0;
 
-  return do_scsi_cmd(dev, &cbw_scsi.cbw, 0, false);
-}
+//   return do_scsi_cmd(dev, &cbw_scsi.cbw, 0, false);
+// }
diff --git a/Source/HBIOS/ch376-native/source-doc/scsi-drv/class_scsi.h b/Source/HBIOS/ch376-native/source-doc/scsi-drv/class_scsi.h
index 5e5b63bf..989e5bec 100644
--- a/Source/HBIOS/ch376-native/source-doc/scsi-drv/class_scsi.h
+++ b/Source/HBIOS/ch376-native/source-doc/scsi-drv/class_scsi.h
@@ -182,12 +182,14 @@ typedef struct {
   _scsi_packet_read_write     scsi_cmd;
 } cbw_scsi_read_write;
 
-extern usb_error scsi_read_capacity(device_config_storage *const dev, scsi_read_capacity_result *result);
-extern usb_error scsi_inquiry(device_config_storage *const dev, scsi_inquiry_result *inq_result);
-extern usb_error scsi_sense_init(device_config_storage *const dev);
-extern usb_error scsi_test(device_config_storage *const dev);
-extern usb_error scsi_request_sense(device_config_storage *const dev, scsi_sense_result *const sens_result);
-extern usb_error scsi_eject(device_config_storage *const dev);
-extern usb_error scsi_read(const uint16_t dev, uint8_t *const buffer);
-extern usb_error scsi_write(device_config_storage *const dev, uint8_t *const buffer);
+extern usb_error scsi_read_capacity(const uint16_t dev_index, scsi_read_capacity_result *result);
+extern usb_error scsi_inquiry(const uint16_t dev_index, scsi_inquiry_result *inq_result);
+extern usb_error scsi_sense_init(const uint16_t dev_index);
+// extern usb_error scsi_request_sense(const uint16_t dev_index, scsi_sense_result *const sens_result);
+// extern usb_error scsi_eject(device_config_storage *const dev);
+extern usb_error scsi_read(const uint16_t dev_index, uint8_t *const buffer);
+extern usb_error scsi_write(const uint16_t dev_index, uint8_t *const buffer);
+
+extern usb_error scsi_seek(const uint16_t dev_index, const uint32_t lba);
+
 #endif
diff --git a/Source/HBIOS/ch376-native/source-doc/scsi-drv/scsi-init.c b/Source/HBIOS/ch376-native/source-doc/scsi-drv/scsi-init.c
index 6438ef4d..e4928d0f 100644
--- a/Source/HBIOS/ch376-native/source-doc/scsi-drv/scsi-init.c
+++ b/Source/HBIOS/ch376-native/source-doc/scsi-drv/scsi-init.c
@@ -1,4 +1,5 @@
 #include "class_scsi.h"
+#include "hbios-driver-storage.h"
 #include <ch376.h>
 #include <enumerate.h>
 #include <hbios.h>
@@ -7,7 +8,6 @@
 #include <usb-base-drv.h>
 #include <work-area.h>
 #include <z80.h>
-#include "hbios-driver-storage.h"
 
 extern const uint16_t const ch_scsi_fntbl[];
 
@@ -22,17 +22,16 @@ void chscsi_init(void) {
     const usb_device_type t = storage_device->type;
 
     if (t == USB_IS_MASS_STORAGE) {
-      const uint8_t dev_index = find_storage_dev();  //index == -1 (no more left) should never happen
-      hbios_usb_storage_devices[dev_index].storage_device = storage_device;
+      const uint8_t dev_index                          = find_storage_dev(); // index == -1 (no more left) should never happen
       hbios_usb_storage_devices[dev_index].drive_index = dev_index + 1;
-      hbios_usb_storage_devices[dev_index].usb_device = index;
+      hbios_usb_storage_devices[dev_index].usb_device  = index;
 
       print_string("\r\nUSB: MASS STORAGE @ $");
       print_uint16(index);
       print_string(":$");
       print_uint16(dev_index + 1);
       print_string(" $");
-      scsi_sense_init(storage_device);
+      scsi_sense_init(index);
       dio_add_entry(ch_scsi_fntbl, &hbios_usb_storage_devices[dev_index]);
     }
 
diff --git a/Source/HBIOS/ch376-native/source-doc/ufi-drv/class_ufi.h b/Source/HBIOS/ch376-native/source-doc/ufi-drv/class_ufi.h
index 1b761bd9..2649fc18 100644
--- a/Source/HBIOS/ch376-native/source-doc/ufi-drv/class_ufi.h
+++ b/Source/HBIOS/ch376-native/source-doc/ufi-drv/class_ufi.h
@@ -204,4 +204,6 @@ usb_error ufi_send_diagnostics(device_config *const storage_device);
 
 uint32_t convert_from_msb_first(const uint8_t *const buffer);
 
+extern usb_error ufi_seek(const uint16_t dev_index, const uint32_t lba);
+
 #endif
diff --git a/Source/HBIOS/ch376-native/source-doc/ufi-drv/ufi-init.c b/Source/HBIOS/ch376-native/source-doc/ufi-drv/ufi-init.c
index ebd6a64f..3a1af894 100644
--- a/Source/HBIOS/ch376-native/source-doc/ufi-drv/ufi-init.c
+++ b/Source/HBIOS/ch376-native/source-doc/ufi-drv/ufi-init.c
@@ -1,11 +1,11 @@
 #include "class_ufi.h"
+#include "hbios-driver-storage.h"
 #include <dev_transfers.h>
 #include <hbios.h>
 #include <print.h>
 #include <string.h>
 #include <usb-base-drv.h>
 #include <work-area.h>
-#include "hbios-driver-storage.h"
 
 extern const uint16_t const ch_ufi_fntbl[];
 
@@ -21,11 +21,10 @@ void chufi_init(void) {
     const usb_device_type t = storage_device->type;
 
     if (t == USB_IS_FLOPPY) {
-      const uint8_t dev_index = find_storage_dev();  //dev_index == -1 (no more left) should never happen
-      hbios_usb_storage_devices[dev_index].storage_device = storage_device;
+      const uint8_t dev_index                          = find_storage_dev(); // dev_index == -1 (no more left) should never happen
       hbios_usb_storage_devices[dev_index].drive_index = dev_index + 1;
-      hbios_usb_storage_devices[dev_index].usb_device = index;
-      
+      hbios_usb_storage_devices[dev_index].usb_device  = index;
+
       print_string("\r\nUSB: FLOPPY @ $");
       print_uint16(index);
       print_string(":$");
@@ -37,7 +36,9 @@ void chufi_init(void) {
   } while (++index != MAX_NUMBER_OF_DEVICES + 1);
 }
 
-uint32_t chufi_get_cap(device_config *const dev) {
+uint32_t chufi_get_cap(const uint16_t dev_index) {
+  device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+
   ufi_format_capacities_response response;
   memset(&response, 0, sizeof(ufi_format_capacities_response));
 
@@ -56,7 +57,8 @@ uint32_t chufi_get_cap(device_config *const dev) {
   return convert_from_msb_first(response.descriptors[0].number_of_blocks);
 }
 
-uint8_t chufi_read(device_config_storage *const dev, uint8_t *const buffer) {
+uint8_t chufi_read(const uint16_t dev_index, uint8_t *const buffer) {
+  device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
 
   if (wait_for_device_ready((device_config *)dev, 20) != 0)
     return -1; // Not READY!
@@ -85,7 +87,8 @@ uint8_t chufi_read(device_config_storage *const dev, uint8_t *const buffer) {
   return USB_ERR_OK;
 }
 
-usb_error chufi_write(device_config_storage *const dev, uint8_t *const buffer) {
+usb_error chufi_write(const uint16_t dev_index, uint8_t *const buffer) {
+  device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
 
   if (wait_for_device_ready((device_config *)dev, 20) != 0)
     return -1; // Not READY!
diff --git a/Source/HBIOS/ch376-native/ufi-drv/ufi-init.c.s b/Source/HBIOS/ch376-native/ufi-drv/ufi-init.c.s
index 377e8fb6..78a119d8 100644
--- a/Source/HBIOS/ch376-native/ufi-drv/ufi-init.c.s
+++ b/Source/HBIOS/ch376-native/ufi-drv/ufi-init.c.s
@@ -64,94 +64,74 @@ l_chufi_init_00105:
 ;source-doc/ufi-drv/ufi-init.c:16: device_config_storage *const storage_device = (device_config_storage *)get_usb_device_config(index);
 	ld	a,(ix-1)
 	call	_get_usb_device_config
+	ld	l, e
 ;source-doc/ufi-drv/ufi-init.c:18: if (storage_device == NULL)
-	ld	a, d
+	ld	a,d
+	ld	h,a
 	or	e
 	jr	Z,l_chufi_init_00108
 ;source-doc/ufi-drv/ufi-init.c:21: const usb_device_type t = storage_device->type;
-	ld	l, e
-	ld	h, d
 	ld	a, (hl)
 	and	0x0f
 ;source-doc/ufi-drv/ufi-init.c:23: if (t == USB_IS_FLOPPY) {
 	dec	a
 	jr	NZ,l_chufi_init_00106
-;source-doc/ufi-drv/ufi-init.c:24: const uint8_t dev_index = find_storage_dev();  //dev_index == -1 (no more left) should never happen
-	push	de
+;source-doc/ufi-drv/ufi-init.c:24: const uint8_t dev_index                          = find_storage_dev(); // dev_index == -1 (no more left) should never happen
 	call	_find_storage_dev
-	ld	c, l
-	pop	de
-;source-doc/ufi-drv/ufi-init.c:25: hbios_usb_storage_devices[dev_index].storage_device = storage_device;
-	ld	(ix-3),c
+;source-doc/ufi-drv/ufi-init.c:25: hbios_usb_storage_devices[dev_index].drive_index = dev_index + 1;
+	ld	(ix-3),l
 	ld	(ix-2),0x00
+	ld	c,l
 	pop	hl
 	push	hl
 	add	hl, hl
-	add	hl, hl
-	ld	a,+((_hbios_usb_storage_devices) & 0xFF)
-	add	a,l
-	ld	l,a
-	ld	a,+((_hbios_usb_storage_devices) / 256)
-	adc	a,h
-	ld	h,a
-	ld	(hl), e
-	inc	hl
-	ld	(hl), d
-	dec	hl
-;source-doc/ufi-drv/ufi-init.c:26: hbios_usb_storage_devices[dev_index].drive_index = dev_index + 1;
-	ld	e, l
-	ld	d, h
-	inc	de
-	inc	de
-	ld	a, c
-	inc	a
-	ld	(de), a
-;source-doc/ufi-drv/ufi-init.c:27: hbios_usb_storage_devices[dev_index].usb_device = index;
-	ld	c, l
-	ld	b, h
-	inc	bc
-	inc	bc
+	ld	de,_hbios_usb_storage_devices
+	add	hl, de
+	ld	e,l
+	ld	d,h
+	inc	c
+	ld	(hl), c
+;source-doc/ufi-drv/ufi-init.c:26: hbios_usb_storage_devices[dev_index].usb_device  = index;
+	ld	c, e
+	ld	b, d
 	inc	bc
 	ld	a,(ix-1)
 	ld	(bc), a
-;source-doc/ufi-drv/ufi-init.c:29: print_string("\r\nUSB: FLOPPY @ $");
-	push	hl
+;source-doc/ufi-drv/ufi-init.c:28: print_string("\r\nUSB: FLOPPY @ $");
+	push	de
 	ld	hl,ufi_init_str_0
 	call	_print_string
-	pop	hl
-;source-doc/ufi-drv/ufi-init.c:30: print_uint16(index);
-	ld	e,(ix-1)
-	ld	d,0x00
-	push	hl
-	ex	de, hl
+	pop	de
+;source-doc/ufi-drv/ufi-init.c:29: print_uint16(index);
+	ld	l,(ix-1)
+	ld	h,0x00
+	push	de
 	call	_print_uint16
-;source-doc/ufi-drv/ufi-init.c:31: print_string(":$");
+;source-doc/ufi-drv/ufi-init.c:30: print_string(":$");
 	ld	hl,ufi_init_str_1
 	call	_print_string
-	pop	hl
-;source-doc/ufi-drv/ufi-init.c:32: print_uint16(dev_index + 1);
 	pop	de
-	push	de
-	inc	de
+;source-doc/ufi-drv/ufi-init.c:31: print_uint16(dev_index + 1);
+	pop	hl
 	push	hl
-	ex	de, hl
+	inc	hl
+	push	de
 	call	_print_uint16
-;source-doc/ufi-drv/ufi-init.c:33: print_string(" $");
+;source-doc/ufi-drv/ufi-init.c:32: print_string(" $");
 	ld	hl,ufi_init_str_2
 	call	_print_string
-	pop	hl
-;source-doc/ufi-drv/ufi-init.c:34: dio_add_entry(ch_ufi_fntbl, &hbios_usb_storage_devices[dev_index]);
-	ex	de, hl
+	pop	de
+;source-doc/ufi-drv/ufi-init.c:33: dio_add_entry(ch_ufi_fntbl, &hbios_usb_storage_devices[dev_index]);
 	ld	hl,_ch_ufi_fntbl
 	call	_dio_add_entry
 l_chufi_init_00106:
-;source-doc/ufi-drv/ufi-init.c:37: } while (++index != MAX_NUMBER_OF_DEVICES + 1);
+;source-doc/ufi-drv/ufi-init.c:36: } while (++index != MAX_NUMBER_OF_DEVICES + 1);
 	inc	(ix-1)
 	ld	a,(ix-1)
 	sub	0x07
 	jr	NZ,l_chufi_init_00105
 l_chufi_init_00108:
-;source-doc/ufi-drv/ufi-init.c:38: }
+;source-doc/ufi-drv/ufi-init.c:37: }
 	ld	sp, ix
 	pop	ix
 	ret
@@ -166,7 +146,7 @@ ufi_init_str_1:
 ufi_init_str_2:
 	DEFM " $"
 	DEFB 0x00
-;source-doc/ufi-drv/ufi-init.c:40: uint32_t chufi_get_cap(device_config *const dev) {
+;source-doc/ufi-drv/ufi-init.c:39: uint32_t chufi_get_cap(const uint16_t dev_index) {
 ; ---------------------------------
 ; Function chufi_get_cap
 ; ---------------------------------
@@ -177,7 +157,10 @@ _chufi_get_cap:
 	ld	hl, -72
 	add	hl, sp
 	ld	sp, hl
-;source-doc/ufi-drv/ufi-init.c:42: memset(&response, 0, sizeof(ufi_format_capacities_response));
+;source-doc/ufi-drv/ufi-init.c:40: device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+	ld	a,(ix+4)
+	call	_get_usb_device_config
+;source-doc/ufi-drv/ufi-init.c:43: memset(&response, 0, sizeof(ufi_format_capacities_response));
 	ld	hl,0
 	add	hl, sp
 	ld	b,0x12
@@ -188,67 +171,66 @@ l_chufi_get_cap_00112:
 	ld	(hl), a
 	inc	hl
 	djnz	l_chufi_get_cap_00112
-;source-doc/ufi-drv/ufi-init.c:44: wait_for_device_ready(dev, 25);
+;source-doc/ufi-drv/ufi-init.c:45: wait_for_device_ready(dev, 25);
+	push	de
 	ld	a,0x19
 	push	af
 	inc	sp
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	push	hl
+	push	de
 	call	_wait_for_device_ready
 	pop	af
 	inc	sp
-;source-doc/ufi-drv/ufi-init.c:48: ufi_inquiry(dev, &inquiry);
-	ld	hl,36
+	pop	de
+;source-doc/ufi-drv/ufi-init.c:49: ufi_inquiry(dev, &inquiry);
+	push	de
+	ld	hl,38
 	add	hl, sp
 	push	hl
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	push	hl
+	push	de
 	call	_ufi_inquiry
 	pop	af
-;source-doc/ufi-drv/ufi-init.c:50: wait_for_device_ready(dev, 15);
-	ld	h,0x0f
-	ex	(sp),hl
+	pop	af
+	pop	de
+;source-doc/ufi-drv/ufi-init.c:51: wait_for_device_ready(dev, 15);
+	push	de
+	ld	a,0x0f
+	push	af
 	inc	sp
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	push	hl
+	push	de
 	call	_wait_for_device_ready
 	pop	af
 	inc	sp
-;source-doc/ufi-drv/ufi-init.c:52: const usb_error result = ufi_read_frmt_caps(dev, &response);
+	pop	de
+;source-doc/ufi-drv/ufi-init.c:53: const usb_error result = ufi_read_frmt_caps(dev, &response);
 	ld	hl,0
 	add	hl, sp
 	push	hl
-	ld	l,(ix+4)
-	ld	h,(ix+5)
-	push	hl
+	push	de
 	call	_ufi_read_frmt_caps
 	pop	af
 	pop	af
 	ld	a, l
-;source-doc/ufi-drv/ufi-init.c:53: if (result != USB_ERR_OK)
+;source-doc/ufi-drv/ufi-init.c:54: if (result != USB_ERR_OK)
 	or	a
 	jr	Z,l_chufi_get_cap_00102
-;source-doc/ufi-drv/ufi-init.c:54: return 0;
+;source-doc/ufi-drv/ufi-init.c:55: return 0;
 	ld	hl,0x0000
 	ld	e, l
 	ld	d, l
 	jr	l_chufi_get_cap_00103
 l_chufi_get_cap_00102:
-;source-doc/ufi-drv/ufi-init.c:56: return convert_from_msb_first(response.descriptors[0].number_of_blocks);
+;source-doc/ufi-drv/ufi-init.c:57: return convert_from_msb_first(response.descriptors[0].number_of_blocks);
 	ld	hl,4
 	add	hl, sp
 	push	hl
 	call	_convert_from_msb_first
 	pop	af
 l_chufi_get_cap_00103:
-;source-doc/ufi-drv/ufi-init.c:57: }
+;source-doc/ufi-drv/ufi-init.c:58: }
 	ld	sp, ix
 	pop	ix
 	ret
-;source-doc/ufi-drv/ufi-init.c:59: uint8_t chufi_read(device_config_storage *const dev, uint8_t *const buffer) {
+;source-doc/ufi-drv/ufi-init.c:60: uint8_t chufi_read(const uint16_t dev_index, uint8_t *const buffer) {
 ; ---------------------------------
 ; Function chufi_read
 ; ---------------------------------
@@ -259,10 +241,14 @@ _chufi_read:
 	ld	hl, -20
 	add	hl, sp
 	ld	sp, hl
-;source-doc/ufi-drv/ufi-init.c:61: if (wait_for_device_ready((device_config *)dev, 20) != 0)
-	ld	c,(ix+4)
-	ld	b,(ix+5)
-	push	bc
+;source-doc/ufi-drv/ufi-init.c:61: device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+	ld	a,(ix+4)
+	call	_get_usb_device_config
+;source-doc/ufi-drv/ufi-init.c:63: if (wait_for_device_ready((device_config *)dev, 20) != 0)
+	push	de
+	ld	c,e
+	ld	b,d
+	push	de
 	ld	a,0x14
 	push	af
 	inc	sp
@@ -271,23 +257,22 @@ _chufi_read:
 	pop	af
 	inc	sp
 	ld	a, l
+	pop	de
 	pop	bc
 	or	a
 	jr	Z,l_chufi_read_00102
-;source-doc/ufi-drv/ufi-init.c:62: return -1; // Not READY!
+;source-doc/ufi-drv/ufi-init.c:64: return -1; // Not READY!
 	ld	l,0xff
 	jr	l_chufi_read_00109
 l_chufi_read_00102:
-;source-doc/ufi-drv/ufi-init.c:67: memset(&sense_codes, 0, sizeof(sense_codes));
+;source-doc/ufi-drv/ufi-init.c:69: memset(&sense_codes, 0, sizeof(sense_codes));
 	ld	hl,0
 	add	hl, sp
 	xor	a
 	ld	(hl), a
 	inc	hl
 	ld	(hl), a
-;source-doc/ufi-drv/ufi-init.c:69: if (ufi_read_write_sector((device_config *)dev, false, dev->current_lba, 1, buffer, (uint8_t *)&sense_codes) != USB_ERR_OK)
-	ld	e,(ix+4)
-	ld	d,(ix+5)
+;source-doc/ufi-drv/ufi-init.c:71: if (ufi_read_write_sector((device_config *)dev, false, dev->current_lba, 1, buffer, (uint8_t *)&sense_codes) != USB_ERR_OK)
 	ld	hl,12
 	add	hl, de
 	ld	e, (hl)
@@ -318,11 +303,11 @@ l_chufi_read_00102:
 	pop	bc
 	or	a
 	jr	Z,l_chufi_read_00104
-;source-doc/ufi-drv/ufi-init.c:70: return -1; // general error
+;source-doc/ufi-drv/ufi-init.c:72: return -1; // general error
 	ld	l,0xff
 	jr	l_chufi_read_00109
 l_chufi_read_00104:
-;source-doc/ufi-drv/ufi-init.c:73: memset(&response, 0, sizeof(response));
+;source-doc/ufi-drv/ufi-init.c:75: memset(&response, 0, sizeof(response));
 	push	bc
 	ld	hl,4
 	add	hl, sp
@@ -335,7 +320,7 @@ l_chufi_read_00139:
 	inc	hl
 	djnz	l_chufi_read_00139
 	pop	bc
-;source-doc/ufi-drv/ufi-init.c:75: if ((result = ufi_request_sense((device_config *)dev, &response)) != USB_ERR_OK)
+;source-doc/ufi-drv/ufi-init.c:77: if ((result = ufi_request_sense((device_config *)dev, &response)) != USB_ERR_OK)
 	ld	hl,2
 	add	hl, sp
 	push	hl
@@ -346,29 +331,29 @@ l_chufi_read_00139:
 	ld	a, l
 	or	a
 	jr	Z,l_chufi_read_00106
-;source-doc/ufi-drv/ufi-init.c:76: return -1; // error
+;source-doc/ufi-drv/ufi-init.c:78: return -1; // error
 	ld	l,0xff
 	jr	l_chufi_read_00109
 l_chufi_read_00106:
-;source-doc/ufi-drv/ufi-init.c:80: const uint8_t sense_key = response.sense_key;
+;source-doc/ufi-drv/ufi-init.c:82: const uint8_t sense_key = response.sense_key;
 	ld	hl,4
 	add	hl, sp
 	ld	a, (hl)
-;source-doc/ufi-drv/ufi-init.c:82: if (sense_key != 0)
+;source-doc/ufi-drv/ufi-init.c:84: if (sense_key != 0)
 	and	0x0f
 	jr	Z,l_chufi_read_00108
-;source-doc/ufi-drv/ufi-init.c:83: return -1;
+;source-doc/ufi-drv/ufi-init.c:85: return -1;
 	ld	l,0xff
 	jr	l_chufi_read_00109
 l_chufi_read_00108:
-;source-doc/ufi-drv/ufi-init.c:85: return USB_ERR_OK;
+;source-doc/ufi-drv/ufi-init.c:87: return USB_ERR_OK;
 	ld	l,0x00
 l_chufi_read_00109:
-;source-doc/ufi-drv/ufi-init.c:86: }
+;source-doc/ufi-drv/ufi-init.c:88: }
 	ld	sp, ix
 	pop	ix
 	ret
-;source-doc/ufi-drv/ufi-init.c:88: usb_error chufi_write(device_config_storage *const dev, uint8_t *const buffer) {
+;source-doc/ufi-drv/ufi-init.c:90: usb_error chufi_write(const uint16_t dev_index, uint8_t *const buffer) {
 ; ---------------------------------
 ; Function chufi_write
 ; ---------------------------------
@@ -379,10 +364,14 @@ _chufi_write:
 	ld	hl, -20
 	add	hl, sp
 	ld	sp, hl
-;source-doc/ufi-drv/ufi-init.c:90: if (wait_for_device_ready((device_config *)dev, 20) != 0)
-	ld	c,(ix+4)
-	ld	b,(ix+5)
-	push	bc
+;source-doc/ufi-drv/ufi-init.c:91: device_config_storage *const dev = (device_config_storage *)get_usb_device_config(dev_index);
+	ld	a,(ix+4)
+	call	_get_usb_device_config
+;source-doc/ufi-drv/ufi-init.c:93: if (wait_for_device_ready((device_config *)dev, 20) != 0)
+	push	de
+	ld	c,e
+	ld	b,d
+	push	de
 	ld	a,0x14
 	push	af
 	inc	sp
@@ -391,23 +380,22 @@ _chufi_write:
 	pop	af
 	inc	sp
 	ld	a, l
+	pop	de
 	pop	bc
 	or	a
 	jr	Z,l_chufi_write_00102
-;source-doc/ufi-drv/ufi-init.c:91: return -1; // Not READY!
+;source-doc/ufi-drv/ufi-init.c:94: return -1; // Not READY!
 	ld	l,0xff
 	jr	l_chufi_write_00109
 l_chufi_write_00102:
-;source-doc/ufi-drv/ufi-init.c:95: memset(&sense_codes, 0, sizeof(sense_codes));
+;source-doc/ufi-drv/ufi-init.c:98: memset(&sense_codes, 0, sizeof(sense_codes));
 	ld	hl,0
 	add	hl, sp
 	xor	a
 	ld	(hl), a
 	inc	hl
 	ld	(hl), a
-;source-doc/ufi-drv/ufi-init.c:96: if ((ufi_read_write_sector((device_config *)dev, true, dev->current_lba, 1, buffer, (uint8_t *)&sense_codes)) != USB_ERR_OK) {
-	ld	e,(ix+4)
-	ld	d,(ix+5)
+;source-doc/ufi-drv/ufi-init.c:99: if ((ufi_read_write_sector((device_config *)dev, true, dev->current_lba, 1, buffer, (uint8_t *)&sense_codes)) != USB_ERR_OK) {
 	ld	hl,12
 	add	hl, de
 	ld	e, (hl)
@@ -438,11 +426,11 @@ l_chufi_write_00102:
 	pop	bc
 	or	a
 	jr	Z,l_chufi_write_00104
-;source-doc/ufi-drv/ufi-init.c:97: return -1;
+;source-doc/ufi-drv/ufi-init.c:100: return -1;
 	ld	l,0xff
 	jr	l_chufi_write_00109
 l_chufi_write_00104:
-;source-doc/ufi-drv/ufi-init.c:101: memset(&response, 0, sizeof(response));
+;source-doc/ufi-drv/ufi-init.c:104: memset(&response, 0, sizeof(response));
 	push	bc
 	ld	hl,4
 	add	hl, sp
@@ -455,7 +443,7 @@ l_chufi_write_00139:
 	inc	hl
 	djnz	l_chufi_write_00139
 	pop	bc
-;source-doc/ufi-drv/ufi-init.c:103: if ((ufi_request_sense((device_config *)dev, &response)) != USB_ERR_OK) {
+;source-doc/ufi-drv/ufi-init.c:106: if ((ufi_request_sense((device_config *)dev, &response)) != USB_ERR_OK) {
 	ld	hl,2
 	add	hl, sp
 	push	hl
@@ -466,25 +454,25 @@ l_chufi_write_00139:
 	ld	a, l
 	or	a
 	jr	Z,l_chufi_write_00106
-;source-doc/ufi-drv/ufi-init.c:104: return -1;
+;source-doc/ufi-drv/ufi-init.c:107: return -1;
 	ld	l,0xff
 	jr	l_chufi_write_00109
 l_chufi_write_00106:
-;source-doc/ufi-drv/ufi-init.c:109: const uint8_t sense_key = response.sense_key;
+;source-doc/ufi-drv/ufi-init.c:112: const uint8_t sense_key = response.sense_key;
 	ld	hl,4
 	add	hl, sp
 	ld	a, (hl)
-;source-doc/ufi-drv/ufi-init.c:111: if (sense_key != 0)
+;source-doc/ufi-drv/ufi-init.c:114: if (sense_key != 0)
 	and	0x0f
 	jr	Z,l_chufi_write_00108
-;source-doc/ufi-drv/ufi-init.c:112: return -1;
+;source-doc/ufi-drv/ufi-init.c:115: return -1;
 	ld	l,0xff
 	jr	l_chufi_write_00109
 l_chufi_write_00108:
-;source-doc/ufi-drv/ufi-init.c:114: return USB_ERR_OK;
+;source-doc/ufi-drv/ufi-init.c:117: return USB_ERR_OK;
 	ld	l,0x00
 l_chufi_write_00109:
-;source-doc/ufi-drv/ufi-init.c:115: }
+;source-doc/ufi-drv/ufi-init.c:118: }
 	ld	sp, ix
 	pop	ix
 	ret
diff --git a/Source/HBIOS/ch376scsi.asm b/Source/HBIOS/ch376scsi.asm
index 74c3283d..1144e48d 100644
--- a/Source/HBIOS/ch376scsi.asm
+++ b/Source/HBIOS/ch376scsi.asm
@@ -61,20 +61,26 @@ CH_SCSI_RESET:
 ; sector) are 0 relative.
 ;
 CH_SCSI_SEEK:
+	EXX
+	LD	D, 0
+	LD	E, (IY+1)		; usb_device
+	PUSH	DE
+	POP	IY
+	EXX
+
 	BIT	7,D			; CHECK FOR LBA FLAG
 	CALL	Z,HB_CHS2LBA		; CLEAR MEANS CHS, CONVERT TO LBA
 	RES	7,D			; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
-	EX	DE, HL
 
-	EXX
-	push	IY
-	POP	HL
-	LD	E, (HL)
-	INC	HL
-	LD	D, (HL)
 	PUSH	DE
-	EXX
-	CALL	_chnative_seek
+	PUSH	HL
+	PUSH	IY
+	CALL	_scsi_seek
+	POP	IY
+	POP	HL
+	POP	DE
+
+	XOR	A
 	RET
 ;
 ; ### Function 0x13 -- Disk Read (DIOREAD)
@@ -95,25 +101,25 @@ CH_SCSI_SEEK:
 ;
 CH_SCSI_READ:
 	EXX
-	ld	d, 0
-	ld	e, (iy+3)
-	push	de
-	pop	iy
+	LD	D, 0
+	LD	E, (IY+1)		; usb_device
+	PUSH	DE
+	POP	IY
 	EXX
 
 	CALL	HB_DSKREAD		; HOOK HBIOS DISK READ SUPERVISOR
 
 	; call scsi_read(IY, HL);
 	; HL = HL + 512
-	push	hl
-	push	iy
+	PUSH	HL
+	PUSH	IY
 	call	_scsi_read
-	ld	a, l
-	pop	iy
-	pop	hl
-	ld	bc, 512
-	add	hl, bc
-	ret
+	LD	A, L
+	POP	IY
+	POP	HL
+	LD	BC, 512
+	ADD	HL, BC
+	RET
 ;
 ; ### Function 0x14 -- Disk Write (DIOWRITE)
 ;
@@ -133,11 +139,8 @@ CH_SCSI_READ:
 ;
 CH_SCSI_WRITE:
 	EXX
-	push	IY
-	POP	HL
-	LD	E, (HL)
-	INC	HL
-	LD	D, (HL)
+	LD	D, 0
+	LD	E, (IY+1)		; usb_device
 	PUSH	DE
 	POP	IY
 	EXX
@@ -146,14 +149,14 @@ CH_SCSI_WRITE:
 
 	; call scsi_write(IY, HL);
 	; HL = HL + 512
-	push	hl
-	push	iy
+	PUSH	HL
+	PUSH	IY
 	call	_scsi_write
-	ld	a, l
-	pop	iy
-	pop	hl
-	ld	bc, 512
-	add	hl, bc
+	LD	A, L
+	POP	IY
+	POP	HL
+	LD	BC, 512
+	ADD	HL, BC
 	ret
 
 CH_SCSI_VERIFY:
@@ -206,7 +209,7 @@ CH_SCSI_FORMAT:
 CH_SCSI_DEVICE:
 	LD	C, %00111010
 	LD	D, DIODEV_USB
-	LD	E, (iy+2) 		; drive_index
+	LD	E, (IY+0) 			; drive_index
 	LD	HL, 0
 	XOR	A
 	RET
@@ -252,40 +255,37 @@ CH_SCSI_DEFMED:
 ;
 CH_SCSI_CAP:
 	EXX
-	push	IY
-	POP	HL
-	LD	E, (HL)
-	INC	HL
-	LD	D, (HL)
+	LD	D, 0
+	LD	E, (IY+1)	; usb_device
 	PUSH	DE
 	POP	IY
 	EXX
 
-	push	ix
-	ld	ix, -8		; reserve 8 bytes for 
-	add	ix, sp		; scsi_read_capacity_result
-	ld	sp, ix
+	PUSH	IX
+	LD	IX, -8		; reserve 8 bytes for 
+	ADD	IX, SP		; scsi_read_capacity_result
+	LD	SP, IX
 
-	push	ix
-	push	iy
+	PUSH	IX
+	PUSH	IY
 	call	_scsi_read_capacity
-	pop	iy
-	pop	ix
+	POP	IY
+	POP	IX
 
-	ld	d, (ix)		; response.number_of_blocks[0]
-	ld	e, (ix+1)	; response.number_of_blocks[1]
-	ld	h, (ix+2)	; response.number_of_blocks[2]
-	ld	l, (ix+3)	; response.number_of_blocks[3]
-	ld	b, (ix+6)	; response.block_size[2]
-	ld	c, (ix+7)	; response.block_size[3]
+	LD	D, (IX)		; response.number_of_blocks[0]
+	LD	E, (IX+1)	; response.number_of_blocks[1]
+	LD	H, (IX+2)	; response.number_of_blocks[2]
+	LD	L, (IX+3)	; response.number_of_blocks[3]
+	LD	B, (IX+6)	; response.block_size[2]
+	LD	C, (IX+7)	; response.block_size[3]
 
-	ld	ix, 8
-	add	ix, sp
-	ld	sp, ix
-	pop	ix
+	LD	IX, 8
+	ADD	IX, SP
+	LD	SP, IX
+	POP	IX
 
-	xor	a		; todo determine a drive status
-	ret
+	XOR	A		; todo determine a drive status
+	RET
 ;
 ; ### Function 0x1B -- Disk Geometry (DIOGEOMETRY)
 ;
@@ -305,16 +305,6 @@ CH_SCSI_CAP:
 ; ** Does not appear to be used??
 ;
 CH_SCSI_GEOM:
-	EXX
-	push	IY
-	POP	HL
-	LD	E, (HL)
-	INC	HL
-	LD	D, (HL)
-	PUSH	DE
-	POP	IY
-	EXX
-
 	; FOR LBA, WE SIMULATE CHS ACCESS USING 16 HEADS AND 16 SECTORS
 	; RETURN HS:CC -> DE:HL, SET HIGH BIT OF D TO INDICATE LBA CAPABLE
 	CALL	CH_SCSI_CAP		; GET TOTAL BLOCKS IN DE:HL, BLOCK SIZE TO BC
diff --git a/Source/HBIOS/ch376ufi.asm b/Source/HBIOS/ch376ufi.asm
index 521e76a9..e8b5c8ac 100644
--- a/Source/HBIOS/ch376ufi.asm
+++ b/Source/HBIOS/ch376ufi.asm
@@ -5,6 +5,7 @@
 ;
 
 #include "./ch376-native/ufi-drv.s"
+_ufi_seek	.EQU	_scsi_seek
 
 	; find and mount all floppy USB drives
 CHUFI_INIT	.EQU	_chufi_init
@@ -61,22 +62,25 @@ CH_UFI_RESET:
 ;
 CH_UFI_SEEK:
 	EXX
-	push	IY
-	POP	HL
-	LD	E, (HL)
-	INC	HL
-	LD	D, (HL)
+	LD	D, 0
+	LD	E, (IY+1)		; usb_device
 	PUSH	DE
 	POP	IY
 	EXX
 
-	BIT	7, D			; CHECK FOR LBA FLAG
-	CALL	Z, HB_CHS2LBA		; CLEAR MEANS CHS, CONVERT TO LBA - never seems to happen?
-	RES	7, D
-	EX	DE, HL
+	BIT	7,D			; CHECK FOR LBA FLAG
+	CALL	Z,HB_CHS2LBA		; CLEAR MEANS CHS, CONVERT TO LBA
+	RES	7,D			; CLEAR FLAG REGARDLESS (DOES NO HARM IF ALREADY LBA)
+
+	PUSH	DE
+	PUSH	HL
+	PUSH	IY
+	CALL	_ufi_seek
+	POP	IY
+	POP	HL
+	POP	DE
 
-	push	IY
-	CALL	_chnative_seek
+	XOR	A
 	RET
 ;
 ; ### Function 0x13 -- Disk Read (DIOREAD)
@@ -97,27 +101,24 @@ CH_UFI_SEEK:
 ;
 CH_UFI_READ:
 	EXX
-	push	IY
-	POP	HL
-	LD	E, (HL)
-	INC	HL
-	LD	D, (HL)
+	LD	D, 0
+	LD	E, (IY+1)		; usb_device
 	PUSH	DE
 	POP	IY
 	EXX
 
 	CALL	HB_DSKREAD		; HOOK HBIOS DISK READ SUPERVISOR
 
-	push	hl
-	push	iy
+	PUSH	HL
+	PUSH	IY
 	call	_chufi_read
-	ld	l, 0
-	ld	a, l
-	pop	iy
-	pop	hl
-	ld	bc, 512
-	add	hl, bc
-	ret
+	LD	L, 0
+	LD	A, L
+	POP	IY
+	POP	HL
+	LD	BC, 512
+	ADD	HL, BC
+	RET
 ;
 ; ### Function 0x14 -- Disk Write (DIOWRITE)
 ;
@@ -137,11 +138,8 @@ CH_UFI_READ:
 ;
 CH_UFI_WRITE:
 	EXX
-	push	IY
-	POP	HL
-	LD	E, (HL)
-	INC	HL
-	LD	D, (HL)
+	LD	D, 0
+	LD	E, (IY+1)		; usb_device
 	PUSH	DE
 	POP	IY
 	EXX
@@ -150,15 +148,15 @@ CH_UFI_WRITE:
 
 	; call scsi_write(IY, HL);
 	; HL = HL + 512
-	push	hl
-	push	iy
+	PUSH	HL
+	PUSH	IY
 	call	_chufi_write
-	ld	a, l
-	pop	iy
-	pop	hl
-	ld	bc, 512
-	add	hl, bc
-	ret
+	LD	A, L
+	POP	IY
+	POP	HL
+	LD	BC, 512
+	ADD	HL, BC
+	RET
 
 CH_UFI_VERIFY:
 CH_UFI_FORMAT:
@@ -213,7 +211,7 @@ CH_UFI_FORMAT:
 CH_UFI_DEVICE:
 	LD	C, %11010110
 	LD	D, DIODEV_USB
-	LD	E, (iy+2)		; drive_index
+	LD	E, (IY+0)			; drive_index
 	LD	HL, 0
 	XOR	A
 	RET
@@ -262,21 +260,18 @@ CH_UFI_DEFMED:
 ;
 CH_UFI_CAP:
 	EXX
-	push	IY
-	POP	HL
-	LD	E, (HL)
-	INC	HL
-	LD	D, (HL)
+	LD	D, 0
+	LD	E, (IY+1)		; usb_device
 	PUSH	DE
 	POP	IY
 	EXX
 
-	push	iy
+	PUSH	IY
 	call	_chufi_get_cap
-	pop	iy
-	ld	bc, 512
-	xor	a
-	ret
+	POP	IY
+	LD	BC, 512
+	XOR	A
+	RET
 
 CH_UFI_GEOM:
 	LD	HL, 0