;	Names of ZP and low memory locations
;	(Only those of relevance for the KERNAL)
;	(And only those for now that we feel the need to implement initially)
;	(https://www.c64-wiki.com/wiki/Zeropage)

	.alias TXTTAB $2B
	.alias IOSTATUS $90
	; Keys down clears bits. STOP=bit 7, C= bit 6, SPACE bit 4, CTRL bit 2
	.alias BUCKYSTATUS $91
	.alias kernal_load_or_verify_flag $93
	.alias current_file_num $98
	.alias LDTND $98 ; number of entries in LAT / FAT / SAT tables
	.alias DFLTN $99
	.alias input_device_number DFLTN
	; bit 6 = error messages, bit 7 = control messages
	.alias kernal_message_control_flags $9d
	.alias jiffy_clock_24bits $a0
	.alias cassette_buffer_bytes_used $A6
	.alias load_or_scroll_temp_pointer $AC
	;; We also use the following for temp colour pointer when scrolling
	.alias load_save_verify_end_address $AE
	.alias cassette_buffer_ptr $B2
	.alias current_filename_length $B7
	.alias current_logical_filenum $B8
	.alias current_secondary_address $B9
	.alias current_device_number $BA
	.alias current_filename_ptr $BB
	.alias load_save_start_ptr $C1
	.alias load_save_end_ptr $C3
	.alias last_key_matrix_position $C5
	.alias keys_in_key_buffer $C6
	.alias reverse_video_flag $C7
	.alias end_of_input_line $C8
	.alias start_of_keyboard_input $C9
	.alias current_key_index_entry $CB
	.alias cursor_blink_disable $CC
	.alias cursor_blink_countdown $CD
	.alias cursor_saved_character $CE
	.alias cursor_is_visible $CF
	.alias keyboard_input_ready $D0
	.alias current_screen_line_ptr $D1
	.alias current_screen_x $D3
	.alias quote_mode_flag $D4
	.alias logical_line_length $D5
	.alias current_screen_y $D6
	.alias last_printed_character_ascii $D7
	.alias insert_mode $D8
	; Bits 0 -3 = bits 8-11 of screen line address
	; Bit 7 = line spans multiple physical lines
	.alias screen_line_link_table $D9
	.alias current_screen_line_colour_ptr $F3
	.alias keyboard_decoding_table_ptr $F5
	.alias rs232_rx_buffer_ptr $F7
	.alias rs232_tx_buffer_ptr $F9

	;; 2-byte location below seems to be a good place for temporary storage,
	;; it seems used for timing during tape reads only - see:
	;; - 'C64 Programmer's Reference Guide', page 314
	;; - 'Compute's Mapping the Commodore 64', page 32
	.alias CMP0 $B0 ;; $B0-$B1

	;; Kernal tables for opened files, 10 entries each
	.alias LAT $0259 ; logical file numbers
	.alias FAT $0263 ; device numbers
	.alias SAT $026D ; secondary addresses
	
	; "Compute's Mapping the 64" book
	.alias keyboard_buffer $0277
	.alias MEMSTR $0281
	.alias MEMSIZ $0283 	; NOTE: Mapping the 64 erroniously has the hex as $282, while the DEC is correct
	.alias text_colour $0286 ; p55
	.alias colour_under_cursor $0287 ; p56
	.alias HIBASE $0288     ; p56 (high byte of start of screen)
	.alias key_buffer_size $0289 ; p57

	;; 0 = cursor keys, insert, delete and space repeat, but nothing else
	;; 128 = all keys repeat
	;; 64 = no keys repeat
	.alias key_repeat_flags $028A ; p58
	;; https://www.c64-wiki.com/wiki/Page_2
	.alias key_repeat_counter $028B
	.alias key_first_repeat_delay $028C
	;; bit 0 = shift, 1 = Vendor Key, 2 = Control
	.alias key_bucky_state $028D
	.alias key_last_bucky_state $028E
	.alias keyboard_decoding_ptr $028F
	.alias enable_case_switch $0291
	.alias screen_scroll_disable $0292
	.alias RSSTAT $0297 ; RS-232 status
	.alias pal_or_ntsc $02A6

	;; Kernal vectors - interrupts
	.alias CINV      $0314
	.alias CBINV     $0316 
	.alias NMINV     $0318
	
	;; Kernal vectors - routines
	.alias IOPEN     $031A
	.alias ICLOSE    $031C
	.alias ICHKIN    $031E
	.alias ICKOUT    $0320
	.alias ICLRCH    $0322
	.alias IBASIN    $0324
	.alias IBASOUT   $0326
	.alias ISTOP     $0328
	.alias IGETIN    $032A
	.alias ICLALL    $032C
	.alias USRCMD    $032E
	.alias ILOAD     $0330
	.alias ISAVE     $0331

	;; Under-ROM routines
	;; (BASIC also includes them. XXX - We should de-duplicate them in a safe manner)
	.alias missed_nmi_flag         $2A7
	.alias tiny_nmi_handler		$2A8	
	.alias peek_under_roms tiny_nmi_handler+peek_under_roms_routine-tiny_nmi_handler_routine
	.alias poke_under_roms tiny_nmi_handler+poke_under_roms_routine-tiny_nmi_handler_routine
	.alias memmap_allram tiny_nmi_handler+memmap_allram_routine-tiny_nmi_handler_routine
	.alias memmap_normal tiny_nmi_handler+memmap_normal_routine-tiny_nmi_handler_routine

	;; CIA#2 - https://www.c64-wiki.com/wiki/CIA#CIA_2

	.alias CI2PRA $DD00 ; VIC bank switching and IEC port

	.alias BIT_CI2PRA_ATN_OUT $08    ; 1 - low (pulled), 0 - high (released)
	.alias BIT_CI2PRA_CLK_OUT $10    ; 1 - low (pulled), 0 - high (released)
	.alias BIT_CI2PRA_DAT_OUT $20    ; 1 - low (pulled), 0 - high (released)
	.alias BIT_CI2PRA_CLK_IN  $40    ; 0 - low (pulled), 1 - high (released)
	.alias BIT_CI2PRA_DAT_IN  $80    ; 0 - low (pulled), 1 - high (released)