more work towards Mega65 native mode, added NSYS command

Makefile

@@ -16,6 +16,7 @@ SRCDIR_BASIC   = $(SRCDIR_COMMON) \
                  src/basic/basic_commands \
                  src/basic/basic_commands_01 \
                  src/basic/basic_commands_02 \
+                 src/basic/basic_commands_03_m65 \
                  src/basic/basic_operators \
                  src/basic/basic_functions \
                  src/basic/board_m65 \

doc/Extended-BASIC.md

@@ -91,3 +91,11 @@ Clears the screen content.
 ### `DISPOSE` (all)
 
 Runs the garbage collector - disposes outdated strings.
+
+### `NSYS` (Mega65)
+
+A 'native' `SYS` - same as `SYS`, but does not switch to C64 compatibility mode.
+
+### `GO 64`, `GO 65` (Mega65)
+
+Switches machine to C64 compatibility mode or to MEGA65 native mode. Performs `CLR`

src/aliases/,aliases_hardware_m65.s

@@ -11,7 +11,7 @@
 	// VIC-IV registers
 
 	.label VIC_KEY      = $D02F
-
+	.label VIC_CTRLA    = $D030
 	.label VIC_CTRLB    = $D031
 
 	.label VIC_XPOS     = $D050

src/basic/assets/packed_keywords_03.s

@@ -0,0 +1,12 @@
+// #LAYOUT# STD *       #TAKE
+// #LAYOUT# M65 BASIC_1 #TAKE
+// #LAYOUT# X16 BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+#if ROM_LAYOUT_M65
+
+packed_freq_keywords_03:
+
+	put_packed_freq_keywords_03()
+
+#endif

src/basic/basic_commands/cmd_sys.s

@@ -3,15 +3,39 @@
 // #LAYOUT# *   *       #IGNORE
 
 
+#if ROM_LAYOUT_M65
+
+cmd_nsys:
+	
+	// NSYS requires an argument
+
+	jsr is_end_of_statement
+	bcs_16 do_SYNTAX_error
+	bra cmd_sys_nsys_common
+
+#endif
+
 cmd_sys:
 	
-	jsr is_end_of_statement
-	bcc !+
-
 	// SYS requires an argument
-	jmp do_SYNTAX_error
-	
-!:
+
+	jsr is_end_of_statement
+	bcs_16 do_SYNTAX_error
+
+#if ROM_LAYOUT_M65
+
+	// Make sure we are in C64 compatibility mode
+
+	jsr M65_ISMODE65
+	bne cmd_sys_nsys_common
+	jsr M65_MODE64
+
+	// FALLTROUGH
+
+cmd_sys_nsys_common:
+
+#endif
+
 	//
 	// XXX Temporary ugly hack to support 'SYS PI*656'
 	//

src/basic/basic_commands_03_m65/cmd__jumptable_03.s

@@ -0,0 +1,17 @@
+// #LAYOUT# M65 BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+//
+// Jumptable for BASIC commands with tokens prefixed by $03
+//
+
+.const command_03_list = List().add(
+
+	cmd_nsys
+)
+
+
+command_03_jumptable:
+
+	// Note: 65C02 has the page boundary vector bug fixed!
+	put_jumptable(command_03_list)

src/basic/basic_commands_03_m65/cmd_nsys.s

@@ -0,0 +1,7 @@
+// #LAYOUT# M65 BASIC_0 #TAKE
+// #LAYOUT# *   *       #IGNORE
+
+
+// PLACEHOLDER for completeness - jumptable contains direct address
+
+// NSYS command is implemented together with SYS

src/basic/engine_editor/tokenise_line.s

@@ -98,6 +98,18 @@ tokenise_line_loop:
 	jsr tk_search
 	bcc tokenise_line_keyword_02                 // branch if keyword identified
 
+#endif
+
+#if ROM_LAYOUT_M65
+
+	lda #<packed_freq_keywords_03
+	sta FRESPC+0
+	lda #>packed_freq_keywords_03
+	sta FRESPC+1
+
+	jsr tk_search
+	bcc tokenise_line_keyword_03                 // branch if keyword identified
+
 #endif
 
 	// Shorten packed keyword candidate and try again
@@ -173,6 +185,19 @@ tokenise_line_char:
 
 // Support for extended keyword lists
 
+#if ROM_LAYOUT_M65
+
+tokenise_line_keyword_03:
+
+	// Store the token list index
+
+	lda #$03
+	skip_2_bytes_trash_nvz
+
+	// FALLTROUGH
+
+#endif
+
 #if !HAS_SMALL_BASIC
 
 tokenise_line_keyword_02:

src/basic/engine_runtime/execute_line_statements.s

@@ -46,7 +46,11 @@ execute_statements:
 
 #else
 
+#if ROM_LAYOUT_M65
+	cpx #$04
+#else
 	cpx #$03
+#endif
 	bcc execute_statements_extended
 
 #endif
@@ -93,6 +97,13 @@ execute_statements_extended:
 	cpx #$02
 	beq execute_statements_02
 
+#if ROM_LAYOUT_M65
+
+	cpx #$03
+	beq execute_statements_03
+
+#endif
+
 	jmp do_SYNTAX_error
 
 #endif
@@ -171,6 +182,27 @@ execute_statements_02:
 
 #endif // !HAS_SMALL_BASIC
 
+#if ROM_LAYOUT_M65
+
+execute_statements_03:
+
+	// Get the sub-token, check that it is valid
+
+	jsr fetch_character
+	cmp #$00
+	beq_16 do_SYNTAX_error
+
+	cmp #(TK__MAXTOKEN_keywords_03+1)
+	bcs_16 do_SYNTAX_error
+
+	// Use jumptable to go to the command routine
+
+	asl
+	tax
+	jmp (command_03_jumptable - 2, x)
+
+#endif // ROM_LAYOUT_M65
+
 execute_statements_end_of_line:
 
 	// First check, if we are in direct mode - if so,

src/basic/print/list_single_line.s

@@ -94,6 +94,10 @@ list_not_quote:
 	cmp #$02
 	beq list_display_token_02
 #endif
+#if ROM_LAYOUT_M65
+	cmp #$03
+	beq list_display_token_03
+#endif
 
 	// Check for literals
 	cmp #$7F
@@ -228,6 +232,24 @@ list_display_token_02:
 
 #endif
 
+#if ROM_LAYOUT_M65
+
+list_display_token_03:
+
+	// Display a 2-byte token - for extended BASIC
+	jsr list_fetch_subtoken
+
+	// Check if token is known
+	cpx #TK__MAXTOKEN_keywords_03
+	bcs list_is_unknown
+
+	// Now ask for it to be printed
+	phy_trash_a
+	jsr print_packed_keyword_03
+	jmp_8 list_display_token_ext_done
+
+#endif
+
 list_fetch_subtoken:
 
 	// Fetch the sub-token

src/basic/print/print_packed_freq_string.s

@@ -55,6 +55,16 @@ print_packed_keyword_02:               // .X - token number
 
 #endif
 
+#if ROM_LAYOUT_M65
+
+print_packed_keyword_03:               // .X - token number
+
+	lda #<packed_freq_keywords_03
+	ldy #>packed_freq_keywords_03
+	bne print_freq_packed_string       // branch always
+
+#endif
+
 print_packed_keyword_V2:               // .X - token number
 
 	lda #<packed_freq_keywords_V2

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

tools/generate_strings.cc

@@ -206,6 +206,17 @@ const StringEntryList GLOBAL_Keywords_02 =  { ListType::KEYWORDS, "keywords_02",
     // (*) see https://sourceforge.net/p/vice-emu/code/HEAD/tree/trunk/vice/src/petcat.c
 } };
 
+// extended BASIC keywords - list reserved for hardware dependent BASIC commands
+
+const StringEntryList GLOBAL_Keywords_03_M65 =  { ListType::KEYWORDS, "keywords_03",
+{
+    // STD    M65    U64    X16
+
+    { false, true,  false, false, "K03_01",   "NSYS",         }, // Not present in CBM BASIC dialects, Open ROMs specific
+
+} };
+
+
 // BASIC errors - all dialects
 
 /*
@@ -1760,6 +1771,7 @@ void writeStrings()
         dataSetM65.addStrings(GLOBAL_Keywords_V2);
         dataSetM65.addStrings(GLOBAL_Keywords_01);
         dataSetM65.addStrings(GLOBAL_Keywords_02);
+        dataSetM65.addStrings(GLOBAL_Keywords_03_M65);
         dataSetM65.addStrings(GLOBAL_Errors);
         dataSetM65.addStrings(GLOBAL_MiscStrings);