diff --git a/src/mon_m65/bsmon.s b/src/mon_m65/bsmon.s
index 5234d254..ec73f38c 100644
--- a/src/mon_m65/bsmon.s
+++ b/src/mon_m65/bsmon.s
@@ -399,64 +399,6 @@ Fetch:
          AND  #$ff
          RTS
 
-; *********
-Mon_Memory:
-; *********
-
-   lda  #$00
-   sta  Adr_Mode             ; by default use C64-style addressing
-
-   jsr  Get_Addr_To_LAC      ; get 1st parameter (start address)
-   +beq Mon_Error
-   jsr  LAC_To_LPC           ; Long_PC = start address
-
-   jsr  Get_Addr_To_LAC      ; get 2nd parameter (end address)
-   bne  @got_end_address
-   jsr  LPC_Plus_Page_To_LAC ; set default end address by start plus one page
-
-@got_end_address:
-
-   jsr  LAC_Minus_LPC        ; Long_CT = range
-   +bcc Mon_Error            ; error if negative range
-
-@loop:
-
-   jsr Print_CR ; XXX for debug only
-   lda Long_CT+3
-   jsr Print_Hex
-   lda Long_CT+2
-   jsr Print_Hex
-   lda Long_CT+1
-   jsr Print_Hex
-   lda Long_CT+0
-   jsr Print_Hex
-
-   jsr Dump_Row
-
-   jsr Print_CR ; XXX for debug only
-   lda Long_CT+3
-   jsr Print_Hex
-   lda Long_CT+2
-   jsr Print_Hex
-   lda Long_CT+1
-   jsr Print_Hex
-   lda Long_CT+0
-   jsr Print_Hex
-   jsr Print_CR
-
-   jsr  STOP
-   beq  @exit
-
-
-   ; !!! loop till end reached
-
-
-
-
-
-@exit:
-
-   jmp Main
 
 
 ; *********
@@ -623,8 +565,6 @@ Dump_4_Chars: ; XXX to be adapted
 Dump_Row:
 ; *******
 
-         JSR  Set_MODE_80
-
          PHZ
          JSR  Print_CR
          LDA  #'>'
diff --git a/src/mon_m65/mon_imports.s b/src/mon_m65/imports.s
similarity index 100%
rename from src/mon_m65/mon_imports.s
rename to src/mon_m65/imports.s
diff --git a/src/mon_m65/mon_command_memory.s b/src/mon_m65/mon_command_memory.s
new file mode 100644
index 00000000..2e460cbe
--- /dev/null
+++ b/src/mon_m65/mon_command_memory.s
@@ -0,0 +1,65 @@
+
+Mon_Memory:
+
+   jsr  Set_MODE_80
+   lda  #$00
+   sta  Adr_Mode             ; by default use C64-style addressing
+
+   jsr  Get_Addr_To_LAC      ; get 1st parameter (start address)
+   +beq Mon_Error
+   jsr  LAC_To_LPC           ; Long_PC = start address
+
+   jsr  Get_Addr_To_LAC      ; get 2nd parameter (end address)
+   bne  @calcdiff
+
+   lda  #$10                 ; by default display 16 rows
+   sta  Long_CT+0
+   lda  #$00
+   sta  Long_CT+1
+   sta  Long_CT+2
+   sta  Long_CT+3
+
+   bra  @loop
+
+@calcdiff:
+   jsr  LAC_Minus_LPC        ; Long_CT = range
+   +bcc Mon_Error            ; error if negative range
+
+   ldx  #$04                 ; for 80 character mode - 16 (2^4) bytes/line
+   bbr7 MODE_80,@shift
+   dex                       ; for 40 character mode - 8  (2^3) bytes/line
+
+@shift:
+   clc
+   ror  Long_CT+3
+   ror  Long_CT+2
+   ror  Long_CT+1
+   ror  Long_CT+0
+
+   dex
+   bne  @shift               ; at the ned of loop Long_CT contains number of rows to show minus 1
+
+@loop:
+
+   jsr  Dump_Row
+   jsr  STOP
+   beq  @exit                ; end if STOP pressed
+
+   sec                       ; XXX consider moving this to separate subroutine
+   lda  Long_CT+0
+   sbc  #$01
+   sta  Long_CT+0
+   lda  Long_CT+1
+   sbc  #$00
+   sta  Long_CT+1
+   lda  Long_CT+2
+   sbc  #$00
+   sta  Long_CT+2
+   lda  Long_CT+3
+   sbc  #$00
+   sta  Long_CT+3
+   bcs  @loop
+
+@exit:
+
+   jmp Main
diff --git a/src/mon_m65/mon_get_addr_to_lac.s b/src/mon_m65/mon_helper_get_addr_to_lac.s
similarity index 100%
rename from src/mon_m65/mon_get_addr_to_lac.s
rename to src/mon_m65/mon_helper_get_addr_to_lac.s