You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
72 lines
1.7 KiB
72 lines
1.7 KiB
BITS 16 |
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
|
print: |
|
; Prints string in si |
|
; IN si: zero terminated string to print |
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
|
mov ah, 0xE ; Specify 'int 0x10' 'teletype output' function |
|
; [AL = Character, BH = Page Number, BL = Colour (in graphics mode)] |
|
.printchar: |
|
lodsb ; Load byte at address SI into AL, and increment SI |
|
test al, al |
|
jz .done ; If the character is zero (NUL), stop writing the string |
|
int 0x10 ; Otherwise, print the character via 'int 0x10' |
|
jmp .printchar ; Repeat for the next character |
|
.done: |
|
ret |
|
|
|
printCRLF: |
|
mov ah, 0xE |
|
mov al, 13 |
|
int 0x10 |
|
mov al, 10 |
|
int 0x10 |
|
ret |
|
|
|
printSpace: |
|
mov ax, 0xE20 |
|
int 0x10 |
|
ret |
|
|
|
printALChar: |
|
mov ah, 0xE |
|
mov bl, 0x02 ;color |
|
int 0x10 |
|
ret |
|
|
|
; Changing the screen the user i looking at. |
|
; value in 'al' is the screen we want to switch to. |
|
; starting from 0x00 |
|
os_change_screen: |
|
; Here the addresses for the screens stack |
|
; and base pointer has to be set. |
|
mov ah, 0x05 |
|
int 0x10 |
|
ret |
|
|
|
os_clear_screen: |
|
pusha |
|
; move cursor to the bootom |
|
xor ax, ax |
|
xor bx, bx |
|
mov ah, 0x02 |
|
mov bh, 0x00 ; page number 0 |
|
mov dh, 0x18 ; row zero |
|
mov dl, 0x00 ; coloumn zero |
|
int 0x10 |
|
xor cx, cx |
|
.loop: |
|
call printCRLF |
|
add cx, 1 |
|
cmp cx, 0x19 ; until blank screen |
|
jne .loop |
|
; Move curser back to the top of the screen |
|
mov ah, 0x02 |
|
mov bh, 0x00 ; page number 0 |
|
mov dh, 0x00 ; row zero |
|
mov dl, 0x00 ; coloumn zero |
|
int 0x10 |
|
|
|
popa |
|
ret |