; Static System Variables ; Name Address Size Status Comment z0 = $0 ; 8 bit All Purpose 16 bit Zero Page Variable z1 = $1 ; 8 bit irq_a = $200 ; 8 bit (internal) IRQ Variable Save irq_x = $201 ; 8 bit (internal) irq_y = $202 ; 8 bit (internal) irq_vector = $203 ; 16 bit (internal) IRQ 16 bit Jump Vector k0 = $205 ; 8 bit General Purpose Kernel Registers, k1 = $206 ; 8 bit usually used as Carry for Sub-Routines k2 = $207 ; 8 bit k3 = $208 ; 8 bit k4 = $209 ; 8 bit k5 = $20a ; 8 bit k6 = $20b ; 8 bit k7 = $20c ; 8 bit keyboard_current = $20d ; 8 bit Held Keyboard Key, without Formatting (shift, etc.) "Scan Key" keyboard_previous = $20e ; 8 bit Previous held "Scan Key" keyboard_format = $20f ; 8 bit Formatted Char, from keyboard_current keyboard_arrow = $210 ; 8 bit Held Arrow Keys keyboard_modifier = $211 ; 8 bit Held Modifier Keys, such as "shift, alt, control" cursor_x = $212 ; 8 bit Current Cursor X Position cursor_y = $213 ; 8 bit Current Cursor Y Position cursor_x_previous = $214 ; 8 bit (internal) Previous Cursor X Position cursor_y_previous = $215 ; 8 bit (internal) Previous Cursor Y Position cursor_value = $216 ; 8 bit cursor_speed = $217 ; 8 bit Cursor Blink Speed (in IRQ Ticks) cursor_speed_count = $218 ; 8 bit (internal) Cursor Blink Speed Counter cursor_delay_interval = $219 ; 8 bit cursor_delay = $21a ; 8 bit cursor_delay_count = $21b ; 8 bit (internal) cursor_delay_switch = $21c ; 8 bit (internal) soft_system_register = $21d ; 8 bit (internal) color = $21e ; 8 bit Fore & Background Color typelength = $21f ; 8 bit Length of typebuffer kernel_stack = $280 ; 256 bytes 256 byte, Kernel Stack, used for offloading Registers typebuffer = $380 ; 256 bytes 256 byte, All Purpose Char Buffer ; END => $480 ; Hardware Registers vidx = $be00 ; 8 bit Video X Register vidy = $be01 ; 8 bit Video Y Register vidm = $be02 ; 8 bit Video Modifier Register vidd = $be03 ; 8 bit Video Data Register porta = $bf80 ; 8 bit VIA Registers portb = $bf81 ; 8 bit ... ddrb = $bf82 ; 8 bit ddra = $bf83 ; 8 bit t1cl = $bf84 ; 8 bit t1ch = $bf85 ; 8 bit acr = $bf8b ; 8 bit ifr = $bf8d ; 8 bit ier = $bf8e ; 8 bit keyboard_port = $bd00 ; 8 bit Keyboard Scan-Row Input system_register = $bc00 ; 8 bit System Register ;----------------------------------------------------------------------------------------------- ; Memory Map ;----------------------------------------------------------------------------------------------- ; $00-$ff: Mostly free Zero page, except for $00 and $01 ;----------------------------------------------------------------------------------------------- ; $100-$1ff: Stack ;----------------------------------------------------------------------------------------------- ; $200-$27f: Kernel Variables ;----------------------------------------------------------------------------------------------- ; $280-$37f: Kernel Stack ;----------------------------------------------------------------------------------------------- ; $380-$47f: Typebuffer ;----------------------------------------------------------------------------------------------- ; ;----------------------------------------------------------------------------------------------- ; ;-----------------------------------------------------------------------------------------------