more work towards Mega65 native mode, added NSYS command

src/kernal/board_m65/4000.mega65_vectable_kernal_1.s

@@ -18,10 +18,11 @@
 	.label VK1__load_tape_turbo        = $4000 + 2 * 4
 	.label VK1__load_tape_auto         = $4000 + 2 * 5
 	.label VK1__tape_head_align        = $4000 + 2 * 6
-	.label VK1__M65_MODE64             = $4000 + 2 * 7
-	.label VK1__M65_MODE65             = $4000 + 2 * 8
-	.label VK1__M65_SCRMODEGET         = $4000 + 2 * 9
-	.label VK1__M65_SCRMODESET         = $4000 + 2 * 10
+	.label VK1__m65_chrout_screen      = $4000 + 2 * 7
+	.label VK1__M65_MODE64             = $4000 + 2 * 8
+	.label VK1__M65_MODE65             = $4000 + 2 * 9
+	.label VK1__M65_SCRMODEGET         = $4000 + 2 * 10
+	.label VK1__M65_SCRMODESET         = $4000 + 2 * 11
 
 #else
 
@@ -55,6 +56,8 @@
 	.word $0000
 #endif
 
+	.word m65_chrout_screen
+
 	.word M65_MODE64
 	.word M65_MODE65
 	.word M65_SCRMODEGET

src/kernal/board_m65/mega65_redirect_screen.s

@@ -0,0 +1,15 @@
+// #LAYOUT# M65 KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+//
+// ROM routine call redirect for Mega65 screen routines
+//
+
+
+m65_chrout_screen:
+
+	jsr     map_KERNAL_1
+	jsr_ind VK1__m65_chrout_screen
+	jsr     map_NORMAL
+	jmp chrout_done_success
+

src/kernal/extapi_m65/mega65_mode64.s

@@ -22,6 +22,11 @@ M65_MODE64:
 	lda #$03
 	sta MISC_EMU
 
+	// Set misc VIC-IV flags
+
+	lda %00000000  // enable C64 character set
+	sta VIC_CTRLA
+
 	// Switch to VIC-II mode
 
 	sta VIC_KEY

src/kernal/extapi_m65/mega65_mode65.s

@@ -32,6 +32,11 @@ M65_MODE65:
 	lda #$00
 	sta MISC_EMU
 
+	// Set misc VIC-IV flags
+
+	lda %01000000  // enable C65 character set
+	sta VIC_CTRLA
+
 	// XXX
 
 	// Set screen mode to 80x25

src/kernal/interrupts/ea31.default_irq_handler.s

@@ -15,11 +15,30 @@ default_irq_handler:
 
 #endif // CONFIG_RS232_UP9600
 
+#if ROM_LAYOUT_M65
+
+	jsr M65_ISMODE65
+	bne !+
+
+	jsr m65_cursor_blink
+
+	bra default_irq_handler_common
+!:
+	jsr cursor_blink
+
+default_irq_handler_common:
+
+	jsr JSCNKEY
+	jsr JUDTIM // update jiffy clock
+
+#else
 
 	jsr cursor_blink
 	jsr JSCNKEY
 	jsr JUDTIM // update jiffy clock
 
+#endif
+
 
 #if CONFIG_TAPE_NORMAL || CONFIG_TAPE_TURBO
 

src/kernal/screen/chrout_screen.s

@@ -10,6 +10,13 @@
 
 chrout_screen:
 
+#if ROM_LAYOUT_M65
+
+	jsr M65_ISMODE65
+	beq_16 m65_chrout_screen
+
+#endif
+
 	jsr cursor_hide_if_visible
 
 	lda SCHAR

src/kernal/screen/screen_off.s

@@ -8,7 +8,7 @@
 //
 
 
-#if ((CONFIG_TAPE_NORMAL || CONFIG_TAPE_TURBO) && !CONFIG_MB_MEGA_65) || (CONFIG_IEC_JIFFYDOS && !CONFIG_MEMORY_MODEL_60K)
+#if ((CONFIG_TAPE_NORMAL || CONFIG_TAPE_TURBO)) || (CONFIG_IEC_JIFFYDOS && !CONFIG_MEMORY_MODEL_60K)
 
 
 screen_off:

src/kernal/screen_m65/mega65_chrout_screen.s

@@ -0,0 +1,9 @@
+// #LAYOUT# M65 KERNAL_1 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+m65_chrout_screen:
+
+	// Provide implementation
+
+	rts

src/kernal/screen_m65/mega65_cursor.s

@@ -0,0 +1,9 @@
+// #LAYOUT# M65 KERNAL_0 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+m65_cursor_blink:
+
+	// XXX provide implementation
+
+	rts

src/kernal/screen_m65/mega65_screen_tables.s

@@ -0,0 +1,11 @@
+// #LAYOUT# M65 KERNAL_1 #TAKE
+// #LAYOUT# *   *        #IGNORE
+
+
+// Table of parameters for VIC control register B
+
+m65_scrtab_vic_ctrlb:
+
+	.byte %00100000 // 40x25 + extended attributes
+	.byte %10100000 // 80x25 + extended attributes
+	.byte %10100100 // 80x50 + extended attributes

src/kernal/screen_m65/mega65_scrmodeset.s

@@ -60,7 +60,7 @@ m65_scrmodeset_internal: // entry point for M65_MODE65
 	stx VIC_SCRNPTR+1
 	stx M65_SCRTXTBASE+1
 
-	// Set flags/varaibles for 40/80 columns and 25/50 rows
+	// Set flags/variables for 40/80 columns and 25/50 rows
 
 	tax
 
@@ -68,11 +68,3 @@ m65_scrmodeset_internal: // entry point for M65_MODE65
 	sta VIC_CTRLB
 
 	rts
-
-
-
-m65_scrtab_vic_ctrlb:
-
-	.byte %00000000 // 40x25
-	.byte %10000000 // 80x25
-	.byte %10000100 // 80x50