diff --git a/src/,,config_mega65.s b/src/,,config_mega65.s
index 6dcd28d8..37bca28b 100644
--- a/src/,,config_mega65.s
+++ b/src/,,config_mega65.s
@@ -30,7 +30,6 @@
 ;; #CONFIG# IEC_DOLPHINDOS             NO
 ;; #CONFIG# IEC_DOLPHINDOS_FAST        NO
 ;; #CONFIG# IEC_JIFFYDOS               NO        ; fastloaders do not work on MEGA65 yet!
-;; #CONFIG# IEC_JIFFYDOS_BLANK         NO
 ;; #CONFIG# IEC_BURST_M65              NO        ; please keep disabled for now
 
 
diff --git a/src/aliases/,aliases_config.s b/src/aliases/,aliases_config.s
index 5d00e55f..eaffde27 100644
--- a/src/aliases/,aliases_config.s
+++ b/src/aliases/,aliases_config.s
@@ -112,6 +112,7 @@
 !ifdef CONFIG_MB_MEGA65 {
 	!ifdef CONFIG_IEC_BURST_CIA1 { !error "Do not use CONFIG_IEC_BURST_CIA1 options for MEGA65 motherboard, CONFIG_IEC_BURST_M65 instead" }
 	!ifdef CONFIG_IEC_BURST_CIA2 { !error "Do not use CONFIG_IEC_BURST_CIA2 options for MEGA65 motherboard, CONFIG_IEC_BURST_M65 instead" }
+	!ifdef IEC_JIFFYDOS_BLANK    { !error "Do not use IEC_JIFFYDOS_BLANK option for MEGA65 motherboard, it is not needed"                 }
 	!ifndef CONFIG_DOS_WEDGE     { !error "MEGA65 build requires CONFIG_DOS_WEDGE" }
 }
 !ifndef CONFIG_MB_MEGA65 {
diff --git a/src/kernal/board_m65/mega65_iec_slow_fast.s b/src/kernal/board_m65/mega65_iec_slow_fast.s
deleted file mode 100644
index 310df6e3..00000000
--- a/src/kernal/board_m65/mega65_iec_slow_fast.s
+++ /dev/null
@@ -1,45 +0,0 @@
-;; #LAYOUT# M65 KERNAL_0 #TAKE
-;; #LAYOUT# *   *        #IGNORE
-
-;
-; Checks if system is in MEGA65 native mode; if so, switches CPU speed to fast/slow - for IEC routines;
-; Alters only status bits, all remaining registers preserved
-;
-
-!ifdef CONFIG_IEC {
-
-
-m65_iec_slow:
-
-	jsr M65_MODEGET
-	bcs m65_iec_fast_slow_done
-
-	; Switch CPU speed
-
-	pha
-	lda VIC_CTRLB
-	and #%10111111
-	bra m65_iec_fast_slow_common
-
-m65_iec_fast:
-
-	jsr M65_MODEGET
-	bcs m65_iec_fast_slow_done
-
-	pha
-	lda VIC_CTRLB
-	ora #%01000000
-
-	; FALLTROUGH
-
-m65_iec_fast_slow_common:
-
-	sta VIC_CTRLB
-	pla
-
-	; FALLTROUGH
-
-m65_iec_fast_slow_done:
-
-	rts
-}
diff --git a/src/kernal/board_m65/mega65_speed.s b/src/kernal/board_m65/mega65_speed.s
new file mode 100644
index 00000000..3c274ca3
--- /dev/null
+++ b/src/kernal/board_m65/mega65_speed.s
@@ -0,0 +1,105 @@
+;; #LAYOUT# M65 KERNAL_0 #TAKE
+;; #LAYOUT# *   *        #IGNORE
+
+;
+; Checks if system is in MEGA65 native mode; if so, switches CPU speed to fast/slow for IO routines
+; Alters only status bits, all remaining registers preserved
+;
+
+; Entry points:
+; - m65_speed_iec        - at the start of IEC operations
+; - m65_speed_tape_cbdos - at the start of tape or CBDOS operations
+; - m65_speed_restore    - restore current mode standard speed, hide VIC-IV for compatibility mode
+
+
+!ifdef CONFIG_IEC {
+
+m65_speed_iec:
+
+	; If compatibility mode, unlock VIC-IV
+
+	jsr M65_MODEGET
+	pha
+	bcc @1
+	jsr viciv_unhide
+@1:
+	; Switch CPU speed to approx. 1 MHz
+
+	lda #%01000000
+	trb VIC_CTRLB
+
+	; Disable badlines and slow interrupt emulation
+
+	lda #$00
+	sta MISC_EMU
+
+	; Return
+
+	pla
+	rts
+}
+
+
+m65_speed_tape_cbdos:
+
+	; If compatibility mode, unlock VIC-IV
+
+	jsr M65_MODEGET
+	pha
+	bcc @1
+	jsr viciv_unhide
+@1:
+	; Just set the maximum possible speed
+
+	pha
+	bra m65_speed_restore_native
+
+
+
+m65_speed_restore:
+
+	; Restore proper speed depending on the mode
+
+	jsr M65_MODEGET
+	pha
+	bcc m65_speed_restore_native
+
+	; FALLTROUGH
+
+m65_speed_restore_compat:
+
+	; C64 compatibility mode - approx 1 MHz, badlines and slow interrupts enabled
+
+	lda #%01000000
+	trb VIC_CTRLB
+
+	; FALLTROUGH
+
+m65_speed_ME_compat:
+
+	; Reenable badlines and slow interrupt emulation
+
+	lda #$03
+	sta MISC_EMU
+
+	; Hide the VIC-IV
+
+	sta VIC_KEY
+
+	; Return
+
+	pla
+	rts
+
+m65_speed_restore_native:
+
+	; Native mode - maximum speed
+
+	lda #%01000000
+	tsb VIC_CTRLB
+
+	; All the special speed modes disable badlines and slow interrupts,
+	; so there is no need to restore them
+
+	pla
+	rts
diff --git a/src/kernal/errors.s b/src/kernal/errors.s
index 917317d7..0f4bc83a 100644
--- a/src/kernal/errors.s
+++ b/src/kernal/errors.s
@@ -91,8 +91,8 @@ kernalerror_TOP_MEM_RS232:
 	lda #K_ERR_TOP_MEM_RS232
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch back to fast mode
-	jsr m65_iec_fast
+	; Restore the proper speed
+	jsr m65_speed_restore
 }
 	sec
 	rts
diff --git a/src/kernal/iec/iec_return.s b/src/kernal/iec/iec_return.s
index bf9972f7..c80323b7 100644
--- a/src/kernal/iec/iec_return.s
+++ b/src/kernal/iec/iec_return.s
@@ -26,8 +26,8 @@ iec_return_success:
 	+plx_trash_a
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch back to fast mode
-	jsr m65_iec_fast
+	; Restore the proper speed
+	jsr m65_speed_restore
 }
 
 	; Report success
diff --git a/src/kernal/iec/iec_rx_byte.s b/src/kernal/iec/iec_rx_byte.s
index fc565c85..61a7329c 100644
--- a/src/kernal/iec/iec_rx_byte.s
+++ b/src/kernal/iec/iec_rx_byte.s
@@ -17,8 +17,8 @@
 iec_rx_dispatch:
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch to 1 MHz
-	jsr m65_iec_slow
+	; Ensure 1 Mhz mode and disabled badlines
+	jsr m65_speed_iec
 }
 
 	lda IECPROTO
@@ -33,8 +33,8 @@ iec_rx_dispatch:
 iec_rx_byte:
 
 !ifdef CONFIG_MB_M65 { !ifndef CONFIG_IEC_JIFFYDOS {
-	; If in native mode, switch to 1 MHz
-	jsr m65_iec_slow
+	; Ensure 1 Mhz mode and disabled badlines
+	jsr m65_speed_iec
 } }
 
 	; Store .X and .Y on the stack - preserve them
@@ -161,8 +161,8 @@ iec_rx_acknowledge:
 iec_rx_end:
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch back to fast mode
-	jsr m65_iec_fast
+	; Restore the proper speed
+	jsr m65_speed_restore
 }
 
 	+ply_trash_a
diff --git a/src/kernal/iec/iec_turnaround_to_listen.s b/src/kernal/iec/iec_turnaround_to_listen.s
index dd3971bd..861d7385 100644
--- a/src/kernal/iec/iec_turnaround_to_listen.s
+++ b/src/kernal/iec/iec_turnaround_to_listen.s
@@ -21,8 +21,8 @@ iec_turnaround_to_listen:
 	sei
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch to 1 MHz
-	jsr m65_iec_slow
+	; Ensure 1 Mhz mode and disabled badlines
+	jsr m65_speed_iec
 }
 
 	; Pull DATA, release CLK and ATN (we are not sending commands)
diff --git a/src/kernal/iec/iec_tx_byte.s b/src/kernal/iec/iec_tx_byte.s
index feb4b112..93c42625 100644
--- a/src/kernal/iec/iec_tx_byte.s
+++ b/src/kernal/iec/iec_tx_byte.s
@@ -20,8 +20,8 @@ iec_tx_dispatch:
 	php                                ; preserve C flag for EOI indication
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch to 1 MHz
-	jsr m65_iec_slow
+	; Ensure 1 Mhz mode and disabled badlines
+	jsr m65_speed_iec
 }
 
 	lda IECPROTO
@@ -41,9 +41,9 @@ iec_tx_dispatch:
 iec_tx_byte:
 
 !ifdef CONFIG_MB_M65 { !ifndef CONFIG_IEC_JIFFYDOS {
-	; If in native mode, switch to 1 MHz
+	; Ensure 1 Mhz mode and disabled badlines
 	php
-	jsr m65_iec_slow
+	jsr m65_speed_iec
 	plp
 } }
 
diff --git a/src/kernal/iec/iec_tx_command.s b/src/kernal/iec/iec_tx_command.s
index a6b5bc0e..3e4a223d 100644
--- a/src/kernal/iec/iec_tx_command.s
+++ b/src/kernal/iec/iec_tx_command.s
@@ -39,8 +39,8 @@ iec_tx_command:
 	; and transmits a byte
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch to 1 MHz
-	jsr m65_iec_slow
+	; Ensure 1 Mhz mode and disabled badlines
+	jsr m65_speed_iec
 }
 	clc ; Carry flag set is used for EOI mark
 	jmp iec_tx_common
diff --git a/src/kernal/iec_fast/dolphindos_load.s b/src/kernal/iec_fast/dolphindos_load.s
index 7a8edd07..4785c0e6 100644
--- a/src/kernal/iec_fast/dolphindos_load.s
+++ b/src/kernal/iec_fast/dolphindos_load.s
@@ -29,8 +29,8 @@ dolphindos_load:
 }
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch to 1 MHz
-	jsr m65_iec_slow
+	; Ensure 1 Mhz mode and disabled badlines
+	jsr m65_speed_iec
 }
 	; FALLTROUGH
 
@@ -115,8 +115,8 @@ dolphindos_load_no_eoi:
 dolphindos_load_end:
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch back to fast mode
-	jsr m65_iec_fast
+	; Restore the proper speed
+	jsr m65_speed_restore
 }
 	; Update EAL
 	clc
diff --git a/src/kernal/iec_fast/jiffydos_load.s b/src/kernal/iec_fast/jiffydos_load.s
index 12c59179..6b9dabd7 100644
--- a/src/kernal/iec_fast/jiffydos_load.s
+++ b/src/kernal/iec_fast/jiffydos_load.s
@@ -87,10 +87,6 @@ jiffydos_load:
 	; A trick to shorten EAL update time
 	ldy #$FF
 
-!ifdef CONFIG_MB_M65 {
-	; If in native mode, switch to 1 MHz
-	jsr m65_iec_fast
-}
 	; FALLTROUGH
 
 jiffydos_load_loop_esc:
@@ -195,8 +191,8 @@ jiffydos_load_end:
 	ldy #$FF
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch to 1 MHz
-	jsr m65_iec_slow
+	; Ensure 1 Mhz mode and disabled badlines
+	jsr m65_speed_iec
 }
 	; FALLTROUGH
 
@@ -280,8 +276,8 @@ jiffydos_load_loop:
 jiffydos_load_end:
 
 !ifdef CONFIG_MB_M65 {
-	; If in native mode, switch back to fast mode
-	jsr m65_iec_fast
+	; Restore the proper speed
+	jsr m65_speed_restore
 }
 	; Save last byte
 	tax
diff --git a/src/kernal/iec_fast/jiffydos_wait_line.s b/src/kernal/iec_fast/jiffydos_wait_line.s
index 0fa92846..dbfb4356 100644
--- a/src/kernal/iec_fast/jiffydos_wait_line.s
+++ b/src/kernal/iec_fast/jiffydos_wait_line.s
@@ -13,6 +13,8 @@
 
 jiffydos_wait_line:
 
+!ifdef CONFIG_MB_M65 {                 ; MEGA65 does not need to wait, but has to waste few cycles
+
 	; One might try to optimize the code by checking for disabled screen
 	; (bit 4 of VIC_SCROLY); problem: VIC checks this bit only once per frame:
 	; - https://www.lemon64.com/forum/viewtopic.php?t=56582
@@ -31,5 +33,7 @@ jiffydos_wait_line:
 
 jiffydos_wait_line_done:
 
+}
+
 	rts
 }