; Simple include file - ; Select Main.dasm and click assemble to assemble the full program; :screen_addr equ 0xe000 :char_addr equ 0xe180 :screen_width equ 32 nolist if screen_width != 32 error 'screen width must be 32' end_if define jmp_ set pc, define push_ set push, list :cursor dat screen_addr + screen_width * 4 + 4 :colour dat 0x9100 :store_a dat 0 :store_b dat 0; Print out a zero terminated string immediately following the; instruction that called this routine; eg. jsr print; dat 'my String',0; .code continues from here; No registers are affected by this routine; :print jmp_ print_start; Move the cursor to the next line :newline jmp_ do_newline;;;; Set up the monitor, keyboard and clock; At the moment, this simply initialises the screen buffer to ; a known address;; This uses registers a,b,c,x,y,i,j; :setup jmp_ setup_hw;; System error is called if a fatal error occurs;; :system_error jmp_ system_error:setup_hw hwn i:hw_loop ife i, 0 set pc, hw_discovered sub i, 1 hwq i ife a, 0xf615 ife b, 0x7349 set [monitor_idx], i ife a, 0xb402 ife b, 0x12d0 set [clock_idx], i ife a, 0x7406 ife b, 0x30cf set [keyboard_idx], i set pc, hw_loop; These are set up by the hardware discovery loop above:;:NOT_FOUND equ 0xffff:monitor_idx dat NOT_FOUND ; Index of first monitor connected to cpu, or 0xffff:clock_idx dat NOT_FOUND ; Index of first clock connected to cpu, or 0xffff:keyboard_idx dat NOT_FOUND ; Index of first keyboard connected to cpu, or 0xffff; Now set up the screen with default palette and font:hw_discovered ife [monitor_idx], NOT_FOUND set pc, system_error set a, 0 set b, screen_addr hwi [monitor_idx] set pc, pop;-----------------------------------------------:do_newline set [store_a], a set a,[cursor] and a, 0xffe0 add a, screen_width set [cursor],a set a, [store_a] set pc, pop;----------------------------------------------- :print_start set [store_a], a set [store_b], b set a, pop set b, [cursor] loop set [b], [a] add [b], [colour] add a,1 add b,1 ifn [a], 0 jmp_ loop add a,1 push_ a set a, [store_a] set b, [store_b] set pc, pop; End of Kernel;--------------------------------------------